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The Environment

By its nature, adventuring involves delving into places that are dark, dangerous, and full of mysteries to be explored. The rules in this section cover some of the most important ways in which adventurers interact with the environment in such places.

Falling

A fall from a great height is one of the most common hazards facing an adventurer. At the end of a fall, a creature takes 1d6 bludgeoning damage for every 10 feet it fell, to a maximum of 20d6. The creature lands prone, unless it avoids taking damage from the fall.

Suffocating

A creature can hold its breath for a number of minutes equal to 1 + its Constitution modifier (minimum of 30 seconds).

When a creature runs out of breath or is choking, it can survive for a number of rounds equal to its Constitution modifier (minimum of 1 round). At the start of its next turn, it drops to 0 hit points and is dying, and it can’t regain hit points or be stabilized until it can breathe again.

For example, a creature with a Constitution of 14 can hold its breath for 3 minutes. If it starts suffocating, it has 2 rounds to reach air before it drops to 0 hit points.

Vision and Light

The most fundamental tasks of adventuring— noticing danger, finding hidden objects, hitting an enemy in combat, and targeting a spell, to name just a few—rely heavily on a character’s ability to see.

Darkness and other effects that obscure vision can prove a significant hindrance.

A given area might be lightly or heavily obscured. In a lightly obscured area, such as dim light, patchy fog, or moderate foliage, creatures have disadvantage on Wisdom (Perception) checks that rely on sight.

A heavily obscured area—such as darkness, opaque fog, or dense foliage—blocks vision entirely. A creature effectively suffers from the blinded condition when trying to see something in that area.

The presence or absence of light in an environment creates three categories of illumination: bright light, dim light, and darkness.

  • Bright light lets most creatures see normally. Even gloomy days provide bright light, as do torches, lanterns, fires, and other sources of illumination within a specific radius.
  • Dim light, also called shadows, creates a lightly obscured area. An area of dim light is usually a boundary between a source of bright light, such as a torch, and surrounding darkness. The soft light of twilight and dawn also counts as dim light. A particularly brilliant full moon might bathe the land in dim light.
  • Darkness creates a heavily obscured area. Characters face darkness outdoors at night (even most moonlit nights), within the confines of an unlit dungeon or a subterranean vault, or in an area of magical darkness.

Special Visual Senses

Blindsight

A creature with blindsight can perceive its surroundings without relying on sight, within a specific radius. Creatures without eyes, such as oozes, and creatures with echolocation or heightened senses, such as bats and true dragons, have this sense.

Darkvision

Many creatures in fantasy gaming worlds, especially those that dwell underground, have darkvision.

Within a specified range, a creature with darkvision can see in darkness as if the darkness were dim light, so areas of darkness are only lightly obscured as far as that creature is concerned. However, the creature can’t discern color in darkness, only shades of gray.

Truesight

A creature with truesight can, out to a specific range, see in normal and magical darkness, see invisible creatures and objects, automatically detect visual illusions and succeed on saving throws against them, and perceives the original form of a shapechanger or a creature that is transformed by magic.

Furthermore, the creature can see into the Ethereal Plane.

Food and Water

Characters who don’t eat or drink suffer the effects of exhaustion. Exhaustion caused by lack of food or water can’t be removed until the character eats and drinks the full required amount.

Food

A character needs one pound of food per day and can make food last longer by subsisting on half rations. Eating half a pound of food in a day counts as half a day without food.

A character can go without food for a number of days equal to 3 + his or her Constitution modifier (minimum 1). At the end of each day beyond that limit, a character automatically suffers one level of exhaustion.

A normal day of eating resets the count of days without food to zero.

Water

A character needs one gallon of water per day, or two gallons per day if the weather is hot. A character who drinks only half that much water must succeed on a DC 15 Constitution saving throw or suffer one level of exhaustion at the end of the day. A character with access to even less water automatically suffers one level of exhaustion at the end of the day.

If the character already has one or more levels of exhaustion, the character takes two levels in either case.

Interacting with Objects

A character’s interaction with objects in an environment is often simple to resolve in the game. The player tells the GM that his or her character is doing something, such as moving a lever, and the GM describes what, if anything, happens.

For example, a character might decide to pull a lever, which might, in turn, raise a portcullis, cause a room to flood with water, or open a secret door in a nearby wall. If the lever is rusted in position, though, a character might need to force it. In such a situation, the GM might call for a Strength check to see whether the character can wrench the lever into place. The GM sets the DC for any such check based on the difficulty of the task.

Characters can also damage objects with their weapons and spells. Objects are immune to poison and psychic damage, but otherwise they can be affected by physical and magical attacks much like creatures can. The GM determines an object’s Armor Class and hit points, and might decide that certain objects have resistance or immunity to certain kinds of attacks. (It’s hard to cut a rope with a club, for example.) Objects always fail Strength and Dexterity saving throws, and they are immune to effects that require other saves. When an object drops to 0 hit points, it breaks.

A character can also attempt a Strength check to break an object. The GM sets the DC for any such check.

Resting

Heroic though they might be, adventurers can’t spend every hour of the day in the thick of exploration, social interaction, and combat. They need rest—time to sleep and eat, tend their wounds, refresh their minds and spirits for spellcasting, and brace themselves for further adventure.

Adventurers can take short rests in the midst of an adventuring day and a long rest to end the day.

Short Rest

A short rest is a period of downtime, at least 1 hour long, during which a character does nothing more strenuous than eating, drinking, reading, and tending to wounds.

A character can spend one or more Hit Dice at the end of a short rest, up to the character’s maximum number of Hit Dice, which is equal to the character’s level. For each Hit Die spent in this way, the player rolls the die and adds the character’s Constitution modifier to it. The character regains hit points equal to the total. The player can decide to spend an additional Hit Die after each roll. A character regains some spent Hit Dice upon finishing a long rest, as explained below.

Long Rest

A long rest is a period of extended downtime, at least 8 hours long, during which a character sleeps or performs light activity: reading, talking, eating, or standing watch for no more than 2 hours. If the rest is interrupted by a period of strenuous activity—at least 1 hour of walking, fighting, casting spells, or similar adventuring activity—the characters must begin the rest again to gain any benefit from it.

At the end of a long rest, a character regains all lost hit points. The character also regains spent Hit Dice, up to a number of dice equal to half of the character’s total number of them (minimum of one die). For example, if a character has eight Hit Dice, he or she can regain four spent Hit Dice upon finishing a long rest.

A character can’t benefit from more than one long rest in a 24-hour period, and a character must have at least 1 hit point at the start of the rest to gain its benefits.

Between Adventures

Between trips to dungeons and battles against ancient evils, adventurers need time to rest, recuperate, and prepare for their next adventure. Many adventurers also use this time to perform other tasks, such as crafting arms and armor, performing research, or spending their hard-earned gold.

In some cases, the passage of time is something that occurs with little fanfare or description. When starting a new adventure, the GM might simply declare that a certain amount of time has passed and allow you to describe in general terms what your character has been doing. At other times, the GM might want to keep track of just how much time is passing as events beyond your perception stay in motion.

Lifestyle Expenses

Between adventures, you choose a particular quality of life and pay the cost of maintaining that lifestyle.

Living a particular lifestyle doesn’t have a huge effect on your character, but your lifestyle can affect the way other individuals and groups react to you. For example, when you lead an aristocratic lifestyle, it might be easier for you to influence the nobles of the city than if you live in poverty.

Downtime Activities

Between adventures, the GM might ask you what your character is doing during his or her downtime. Periods of downtime can vary in duration, but each downtime activity requires a certain number of days to complete before you gain any benefit, and at least 8 hours of each day must be spent on the downtime activity for the day to count. The days do not need to be consecutive. If you have more than the minimum amount of days to spend, you can keep doing the same thing for a longer period of time, or switch to a new downtime activity.

Downtime activities other than the ones presented below are possible. If you want your character to spend his or her downtime performing an activity not covered here, discuss it with your GM.

Craft

You can craft nonmagical objects, including adventuring equipment and works of art. You must be proficient with tools related to the object you are trying to create (typically artisan’s tools). You might also need access to special materials or locations necessary to create it. For example, someone proficient with smith’s tools needs a forge in order to craft a sword or suit of armor.

For every day of downtime you spend crafting, you can craft one or more items with a total market value not exceeding 5 gp, and you must expend raw materials worth half the total market value. If something you want to craft has a market value greater than 5 gp, you make progress every day in 5 gp increments until you reach the market value of the item. For example, a suit of plate armor (market value 1,500 gp) takes 300 days to craft by yourself.

Multiple characters can combine their efforts toward the crafting of a single item, provided that the characters all have proficiency with the requisite tools and are working together in the same place.

Each character contributes 5 gp worth of effort for every day spent helping to craft the item. For example, three characters with the requisite tool proficiency and the proper facilities can craft a suit of plate armor in 100 days, at a total cost of 750 gp.

While crafting, you can maintain a modest lifestyle without having to pay 1 gp per day, or a comfortable lifestyle at half the normal cost.

Practice a Profession

You can work between adventures, allowing you to maintain a modest lifestyle without having to pay 1 gp per day. This benefit lasts as long you continue to practice your profession.

If you are a member of an organization that can provide gainful employment, such as a temple or a thieves’ guild, you earn enough to support a comfortable lifestyle instead.

If you have proficiency in the Performance skill and put your performance skill to use during your downtime, you earn enough to support a wealthy lifestyle instead.

Recuperate

You can use downtime between adventures to recover from a debilitating injury, disease, or poison.

After three days of downtime spent recuperating, you can make a DC 15 Constitution saving throw. On a successful save, you can choose one of the following results:

  • End one effect on you that prevents you from regaining hit points.
  • For the next 24 hours, gain advantage on saving throws against one disease or poison currently affecting you.

Research

The time between adventures is a great chance to perform research, gaining insight into mysteries that have unfurled over the course of the campaign.

Research can include poring over dusty tomes and crumbling scrolls in a library or buying drinks for the locals to pry rumors and gossip from their lips.

When you begin your research, the GM determines whether the information is available, how many days of downtime it will take to find it, and whether there are any restrictions on your research (such as needing to seek out a specific individual, tome, or location). The GM might also require you to make one or more ability checks, such as an Intelligence (Investigation) check to find clues pointing toward the information you seek, or a Charisma (Persuasion) check to secure someone’s aid. Once those conditions are met, you learn the information if it is available.

For each day of research, you must spend 1 gp to cover your expenses. This cost is in addition to your normal lifestyle expenses.

Train

You can spend time between adventures learning a new language or training with a set of tools. Your GM might allow additional training options.

First, you must find an instructor willing to teach you. The GM determines how long it takes, and whether one or more ability checks are required.

The training lasts for 250 days and costs 1 gp per day. After you spend the requisite amount of time and money, you learn the new language or gain proficiency with the new tool.

Weather and Terrain

Some magical and nonmagical terrain types are described below. Each includes a description and what school(s) of magic they radiate (if any) when detect magic is cast on them, followed by the area of effect, powers, duration, suggested monsters, magic items, etc.

Important: Unless noted otherwise, any negative effects of magical terrain damage, exhaustion, conditions, penalties, and/or other effects never apply to creatures native to that terrain type (acid, cold, fire, etc.) or to those otherwise allied with or authorized by the primary monster or villain, or to those who worship the same god or warlock patron as the one who created the altar, artifact, idol, or relic responsible for the terrain. This is what we mean when we say, “hostile creatures encountered in this terrain.”

If the GM wishes, this exclusion can also apply to those who share the same belief or philosophy, cleric domain, druid circle, martial arts tradition, or wizard subclass (etc.) as the primary monster or villain and/or the altar, artifact, idol, or relic.

It depends on who (or what) is responsible for causing the magical terrain and who (or what) it designates as “authorized” to ignore and/or benefit from its effects.

Unless noted otherwise, nonmagical terrain damage, penalties, and /or other effects apply equally to all creatures within their area of effect. There are obvious exceptions, such as air elementals won’t be affected by a tornado or windstorm, but other flying, gaseous, or incorporeal creatures will.

Note that when certain types of magic are penalized in a weather or terrain template, this penalty applies equally to all creatures in it regardless of who is considered native, allied, authorized, etc.

Casting Dispel Magic: If you make a successful DC 20 Arcana or Religion check before casting dispel magic, you realize this magical terrain cannot be permanently dispelled short of defeating or driving out the primary monster or villain responsible, and/or removing the altar, artifact, idol, or relic creating the terrain. Make a second DC 20 Arcana or Religion check. If you succeed, you realize this magical terrain can be temporarily suppressed by casting a successful dispel magic (DC 20). This does not remove the difficult terrain, but negates all other effects (such as damage) for you and a number of willing creatures in a stationary 120 foot radius equal to your proficiency bonus; this lasts a number of rounds equal to your proficiency bonus. Afterward, the full effects of the terrain return. This resets the timer on any time-based effects (such as ongoing damage). If you choose to reduce the radius of your dispel magic to 60 feet, you suppress the effects for a number of minutes equal to your proficiency bonus. This does not increase the number of willing creatures you can protect beyond your proficiency bonus. If you choose to reduce the radius of your dispel magic to 30 feet, you suppress the effects for a number of hours equal to your proficiency bonus. This does not increase the number of willing creatures you can protect beyond your proficiency bonus. Make a third DC 20 Arcana or Religion check. If you succeed, you strongly (and accurately) suspect that if the primary monster or villain (or altar, artifact, idol, or relic) enters the radius of your dispel magic, it will automatically negate your spell and immediately restore the terrain’s full effects.

Consecrated/Desecrated Ground: If you are using the consecrated/desecrated ground rules, those effects stack with any and all of this book’s weather and terrain.

Immunity and Resistance: Unless specified otherwise, creatures with immunity or resistance to a specific damage type (acid, cold, fire, etc.) retain that ability in magical or nonmagical weather and terrain. This protects them from damage, but not necessarily from any other effects…

Initiative: If you introduce a new template (such as a burning building, earthquake, etc.) into an encounter already in progress, you may want to call for new Initiative rolls.

Protection Spells: Unless specified otherwise, all protection spells work as normal.

Saving Throws: Unless specified otherwise, all saving throws equal DC 15 for magical weather and terrain and DC 13 for nonmagical.

Spellcasting Ability Scores: Unless specified otherwise, all spells granted by magical terrain use the casting creature’s Intelligence, Wisdom, or Charisma (whichever is higher) as its spellcasting ability score. If you do not wish to calculate the individual creature type’s spellcasting DC, you can use:

  • DC 11 for creatures with CR 1 or less
  • DC 13 for creatures of CR 2-3
  • DC 15 for creatures of CR 4-6
  • DC 17 for creatures of CR 7-9
  • DC 19 for creatures of CR 10+

Weather and Terrain Descriptions

For the purposes of this site, and simplification, the options below are grouped into some categories.

Terrain: Terrain is a feature of the land or other permanent physical features that must be dealt with. Terrain includes lava fields, mountains, swamps, forests, lakes, rivers etc.

Weather Event: Weather events include temporary environmental effects, which may be mundane or magical. Examples include wind storms, tornadoes, fire rains, and the like.

Terrains (Non-magical)

Following are mundane, non-magical terrains that could be found in any campaign setting.

Terrain entries are, by their nature, usually permanent features of a landscape that must be dealt with. However, some terrains may be overcome by either eliminating the terrain, or by figuring out some way of making it less of a challenge to future visitors.

Beach or Shoreline

Nonmagical terrain, air, earth, radiant, thunder, water, ground-based

This is a coastal area close to a lake or ocean featuring rocks, sand, or a combination of both.

Area of Effect: Any, up to 1d10 miles long.

Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the transition from normal to difficult terrain. If you are successful, you may stop before entering.

Difficult Terrain: Unless riding a mount, you move at half-speed in this terrain as the rocks, sand, and/or water slows you (depending on type of beach and your distance from water). If you are wading in the actual water, you move at onethird speed on foot, or at half-speed mounted.

Radiant Damage: If the beach is in a hot climate or a summer month in colder ones, this terrain deals 1 point of radiant damage to all living creatures for every daylight hour they spend exposed to it between 10 am and 6 pm. For every 3 such hours of exposure (up to 2/day), you must make a DC 13 Constitution saving throw or suffer 1 level of exhaustion and take 1d4 radiant damage from sunburn and the heat. Creatures with resistance to radiant damage are immune to these damage and exhaustion effects.

Air, Earth, Radiant, Thunder, and Water Magic: All such magic has its DC increased by +1 and deals an extra 1d4 damage of its type on a failed save. In addition, its range is doubled. If the beach is in a cold climate or in winter months, then cold spells also gain this.

Acid, Fire, Necrotic, and Poison Magic: All such magic within the beach has its DC reduced by -1. Its range is halved.

Melee Attack Penalty: When fighting in wet sand, in water up to waist-high, or on a rocky beach, non-aquatic creatures suffer disadvantage to melee weapon and spell attack rolls.

Ranged Attack Penalty: Due to the blinding sun coming off the water, all creatures suffer disadvantage to ranged weapon and spell attack rolls during peak hot climate or summer daylight hours (10 am to 6 pm) and ranges are halved. Creatures wearing hats, helms, or protective paint under the eyes to deflect the sun suffer no ranged attack penalty.

Lost to the Tides: Anything dropped on a beach within the tidal zone (where the waves come in) will eventually be washed out to sea. Any pits or other ground-based traps in this zone impose disadvantage to spot them. However, there is a 25% chance the trap does not activate due to the sand and/or water.

Stealth: Stealth rolls made on a sandy beach gain advantage. Stealth rolls made on a rocky beach suffer a -2 penalty due to the loose rocks.

Duration: Permanent.

Frozen Lake or Waterway

Nonmagical, weather, cold, ground-based

This is a frozen lake or river, or perhaps a glacier.

  • Area of Effect: Varies by original body of water.
  • Recognize Danger: Make a DC 13 Investigation, Perception, Nature, or Survival check to test whether the ice is thick enough to support your weight. The DC increases to 15 to detect if the ice can support a horse, cart, wagon, etc.
  • Difficult Terrain: You move at one-third-speed as the slippery ice slows you.
  • Cold Damage: This terrain deals 1 point of cold damage to all living or non-cold creatures for every minute they remain exposed to it with bare feet. In addition, every 10 minutes, you must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion from the mental anxiety and physical stress of traversing the ice. Creatures with resistance to cold are immune to these ongoing damage and exhaustion effects.
  • Cold and Water Magic: All such magic has its DC increased by +1 and deals an extra 1d4 damage on a failed save.
  • Fire Magic: All fire magic over or on the ice has its DC reduced by -1.
  • Melee Attack Penalty: Due to the icy conditions, all living or non-cold creatures suffer disadvantage to melee weapon and touch spell attack rolls.
  • Ice Breaker: If you miss with a bludgeoning or piercing melee weapon attack, or with a ranged spell attack, or use an area effect spell on or over the ice that deals acid, fire, force, lightning, radiant, or thunder damage, make a DC 15 Survival check. For every die of damage you dealt beyond the first, add +1 to the DC. If you succeed, the ice holds and does not break. If you fail by 5 or less, the ice visibly cracks in an alarming fashion but does not break (yet). You and everyone in a 60 foot radius have 1d4+1 rounds to get to safety 60+ feet away before the ice breaks. If the check fails by more than 5, the ice instantly breaks apart. Once the ice breaks, all creatures in a 60 foot radius of the break must make a DC 19 Dexterity save or fall into the freezing water below.
Breaking the Ice

Ice has AC 10 and 10 HP per inch of thickness. Its thickness is up to the GM; assume a default of 1d3 inches in early or late winter, and 2d4 in midwinter. Ice is immune to cold, necrotic, poison, and psychic damage. It is vulnerable to acid, fire, force, lightning, and thunder damage. If you are within 10 feet of safety, you are able to leap onto the unbroken ice but are knocked prone. If your save fails by 5 or less, you are able to land (and be knocked prone) on a 10 foot patch of free-floating ice that can support your weight.

While you are on a free-floating ice patch, there is 1 in 6 chance every round that another “safe” ice patch will drift close enough for you to leap onto if you wish to get closer to shore (or to your enemy). Make a DC 17 Dexterity save to leap onto the new patch (and be knocked prone). If you fall into the icy water, you must make a DC 15 Constitution save to make it back to the surface. If you fail by 5 or less, you are stunned for 1 round as the cold hits you. If you fail by more than 5, you are stunned for 1 round and on the round after, your passage back to the surface is blocked by the floating ice.

Every round, you may make a new Constitution save to get back to the surface but the DC increases by +1 every round, and every round you remain in the water (whether you are submerged or not), you suffer 1d6 cold damage.

  • Duration: 1d4 weeks or months depending on location, temperature, time of year, etc., or permanent if it is a glacier.

Jungle

Nonmagical, terrain, acid, earth, poison, water, ground-based

This is a dense, untamed jungle with thick underbrush. There may be game trails, but no roads lead through this part of the jungle.

Area of Effect: Any tropical jungle or rainforest.

Difficult Terrain: You move at one-third speed in this terrain due to the heat, the under-brush, and low-hanging branches. Large mounts cannot be ridden here. If you Dash, fly, or run through this terrain, every round, you must make a DC 13 Dexterity save. If you fail, you have a 70% chance to trip over or run into roots, vines, or branches. You suffer 2 points of bludgeoning damage and are knocked prone.

The other 30% chance is you run into a poisonous plant. You suffer 2 points of poison damage but may continue at your current speed.

Natives move at half-speed and reduce their saving throw DC to 10 when moving faster. A “native” is any creature that has spent at least 6 months living in this or similar terrain, or was born here.

Can’t Beat the Heat: Due to the humidity and fighting the jungle every step, for every hour you spend in this terrain, you must succeed at a DC 13 Constitution save or suffer 1 level of exhaustion. Natives are immune to this.

Tropical Disease: For every day you spend in this terrain, you must succeed at a DC 11 Constitution save or be infected by sewer plague, a catch-all for dengue, malaria, yellow fever, etc.

Easy to Get Lost: Make a DC 13 Nature, Perception, or Survival check to detect if the direction you’re heading leads in the direction you want. As many jungle areas look different when approached from a different direction, the DC increases to 15 to identify if you’ve been through this particular area of the jungle before.

Fighting On a Slope: If you are descending an area that slopes slightly down (or defending it against creatures trying to come up it), you gain a +1 bonus to attack and creatures below you suffer a -1 penalty to their attack. If you are descending an area that slopes strongly down (or defending it against creatures trying to come up it), you gain a +2 bonus to attack and creatures below you suffer a -2 penalty to their attack.

Acid, Nature, Necrotic, Poison, Water, and Web Magic: All such magic has its DC increased by +1 and deals an extra 1d4 damage of its type on a failed save.

Cold, Fire, Lightning, and Radiant Magic: All such magic has its DC decreased by -1 and its range is halved.

Passive Cover: All ranged weapon or spell attack rolls suffer a -2 penalty to hit. Due to how thick the jungle is, unless resting or stopped for any other reason, all creatures that are in motion (even just walking) are assumed to have half-cover even when not actively seeking it.

Active Cover: You have total cover from ranged weapon and spell attack rolls if you are hidden behind a tree or (in many cases) when you are crawling along the jungle floor. You have three-quarter cover if you are mostly hidden behind a tree, only exposing yourself enough to spy, or to make a ranged weapon or any spell attack. You have half-cover if you are Small or Medium size and hiding behind bushes or other tall foliage, of which there is an abundance.

Note that area effect spells ignore bushes and may be able to wrap their damage around trees, or even destroy them. If an area effect spell deals enough damage to destroy the tree you are hiding behind, you take half damage (no save) from that spell instead. Trees of different ages and types will vary in hit points, but a good average is AC 13 (natural armor) and 50 hit points.

Trees have damage resistance to bludgeoning and piercing damage and vulnerability to fire damage.

Tracking and Stealth: Tracking is normal, but Stealth rolls suffer disadvantage due to snapping twigs and rustling leaves. Natives, beasts, fey, and plant creatures gain a +4 Stealth bonus instead.

Duration: Permanent (until destroyed).

River – Rapids

Nonmagical terrain, force, water, ground-based

The characters arrive at a fast-flowing river with exposed rocks. It appears it may require some special attention to cross safely.

Area of Effect: River section up to 1d4 miles long, though the river may contain 1d3 sets of rapids along its length, with each set separated by 1d4 miles of relatively calm water.

Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the transition from normal to difficult terrain. If you are successful, you have 1d4 minutes to prepare.

Difficult Terrain: You move at double speed in the water or in a water vehicle while in rapids, but only with the current. You move at one-third speed when fighting the current.

Bludgeoning Damage: For every mile you travel through these rapids in a water vehicle, or if you fall or jump into the water, you must make a DC 13 Dexterity saving throw. If you succeed, you suffer 1 level of exhaustion from bouncing up and down and running into and/or over rocks. Creatures with resistance to bludgeoning damage are immune to these damage and exhaustion effects.

If the creature steering the water vehicle fails this save, the vehicle collides with a large boulder and suffers 4d10 bludgeoning damage. Regardless of whether the vehicle survives the impact, everyone in it must make a DC 15 Dexterity save. If you succeed, you stay safe in your seat (assuming the vehicle survives). If you fail, you fall out and are swept away before any of your allies have a chance to react.

Make another DC 15 Dexterity save. If you fail, you smash into another boulder and suffer 2d10 bludgeoning damage. You can now choose to stop where you are, or to put yourself back into the current…

Once you are in the current, you must make a new saving throw every mile you travel in the rapids. When you come to the end of the rapids, you must succeed one more save (DC 15) to put yourself safely on the river bank. If you fail, you continue down the river. Every mile, you can make another save to get out of the river. You make these saves at DC 15 while still in the rapids, and at DC 10 when in calm waters.

Force, Thunder, and Water Magic: All such magic has its DC increased by +2 and deals an extra 1d6 damage of its type on a failed save. In addition, its range is doubled. If the rapids are in a cold climate or in winter months, then cold spells also gain these bonuses.

Acid, Fire, Necrotic, and Poison Magic: All such magic within the rapids has its DC reduced by -2. Its range is halved.

River – Crossing

Nonmagical terrain, radiant, water, ground-based

This “terrain” describes any long river crossing that is believed to be the only place to cross for 10d4 miles in either direction… If it is waist- to chest-high, then the party can cross it themselves but with great difficulty, especially if they are bringing mounts or heavy gear along. If the crossing is deeper than that, and is anywhere near a settlement, there may be a ferry connected by a rope from shore to shore. This ferry service charges a fee to cross, which is often discounted for locals, but raised for strangers. The fee also goes up in times of war or hardship, and passage may be refused if the ferryman is threatened, asked to aid in criminal activity, or simply if the ferryman doesn’t like the party’s looks or manners…

Area of Effect: Any suitably wide and/or deep river. The world’s widest rivers range from 1 mile across to up to 50 miles across for an Amazon River equivalent at the height of the rainy season.

Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the transition from normal to difficult terrain. If you are successful, you may stop before entering.

Shallow: Unless riding a mount, you wade at half-speed in this terrain where the water is waist high. If it reaches chest-high in its center, you wade at one-third speed. Those who can swim use their normal swim speed if the river is slow. If the river is fast, you swim at half-speed fighting the current.

Deep: If there is no ferry available, you can only cross a river of this width and depth if you swim (if you can cross it at all). This requires you to succeed at progressively harder DC 10 Athletics check, adding +1 to the DC and requiring a new save every 90 feet you swim in a slow current, or +2 to the DC every 60 feet in a fast current. If you fail any check, you suffer 1 level of exhaustion. If you are in a fast current, you are swept down river 30 feet too. Large or smaller non-aquatic mounts cannot cross a deep river. Huge mounts move at half-speed if it is shallow or one-third speed if the current is fast. Gargantuan mounts move at normal speed if it is shallow or at half-speed in a fast current.

Radiant Damage: If the crossing is in a hot climate or a summer month in colder ones, this terrain deals 1 point of radiant damage to all living creatures for every daylight hour they spend exposed to it between 10 am and 6 pm. For every 3 such hours of exposure (up to 2/day), you must make a DC 13 Constitution saving throw or suffer 1 level of exhaustion and take 1d4 radiant damage from sunburn and the heat. Creatures with resistance to radiant damage are immune to these damage and exhaustion effects.

Crossing on a Ferry: The ferry is a Large to Huge wooden raft or barge made of lashed together timbers. It is AC 10 and has 50 HP. It has immunity to piercing damage and vulnerability to force and fire. Depending on its size and the strength of the ferryman, the ferry can comfortably transport the following:

  • 2-4 Large creatures or mounts and gear
  • 4-8 Medium creatures or mounts and gear
  • 10-20 Small or Tiny creatures and gear

The ferry has a speed of 20 feet per round with a light to medium load and 10 feet per round carrying at or near its maximum load.

When transporting a mix of creatures, use your best judgment. For example, the average ferry could transport 2 Medium creatures with 2 Large creatures or mounts, plus the ferryman.

The ferry is attached by ropes to poles from bank to bank and propelled by a long pole for pushing off against the bottom. If the river is too deep to allow for that, then another system will be put in place to get it from shore to shore. Note that ferries can only realistically cross rivers up to 1d4+1 miles wide, and you will need to hire a boat to cross anything larger, like the Amazon.

Fighting On a River Bank: If you are descending a river bank that slopes slightly down (or defending it against creatures trying to come up it), you gain a +1 bonus to attack and creatures below you suffer a -1 penalty to their attack. If you are descending a river bank that slopes strongly down (or defending it against creatures trying to come up it), you gain a +2 bonus to attack and creatures below you suffer a -2 penalty to their attack.

Fighting On a Ferry: Due to the limited and/or cramped space, all creatures on a ferry suffer disadvantage to both melee and ranged weapon and spell attack rolls against other creatures on the ferry. The penalty is reduced to -2 for attacking creatures outside the ferry.

Ranged Attack Penalty: Due to the blinding sun coming off the water, all creatures suffer disadvantage to ranged weapon and spell attack rolls during peak hot climate or summer daylight hours (10 am to 6 pm) and ranges are halved. Creatures wearing hats, helms, or protective paint under the eyes to deflect the sun suffer no ranged attack penalty.

Radiant, Thunder, and Water Magic: All such magic cast in, on, over, or within 60 feet of the river has its DC increased by +1 and deals an extra 1d4 damage of its type on a failed save. In addition, its range is doubled. If the river is in a cold climate or in winter months, then cold spells also gain these bonuses.

Acid, Earth, Fire, Necrotic, and Poison Magic: All such magic cast in, on, over, or within 60 feet of the river has its DC reduced by -1. Its range is halved.

Lost to the River: Anything other than large, heavy objects dropped into the river will be washed away immediately if it has a fast-moving current, or sink to the bottom in a slow current. You must make a DC 20 Dexterity save to recover an item before it sinks in a fast current, or a DC 15 Dexterity save in a slow current. Any pits or other ground-based traps in the river impose disadvantage to spot them. However, there is a 25% chance the trap does not activate due to water.

Tracking and Stealth: Tracking in a river is impossible for non-aquatic creatures. Stealth rolls are impossible while swimming against a fast-moving current. Stealth rolls made while wading a shallow river suffer a -2 penalty.

Duration: The river is permanent, not the ferry.

Options: Use the mud or clay template for fighting on a muddy river bank or dry river bed. You could also stack this template with rain, flood, or other templates. You may also want to rule that undead cannot cross running water (except by a water vehicle).

Sand Dunes (Coastal)

Nonmagical terrain, earth, radiant, water, ground-based

These sand dunes stretch all along the beach.

Pale yellow to golden sand is the most common and the default type encountered. White sand is rarely seen outside the tropics. Black sand will always be located near a volcano. Regardless of sand type, coastal sand dunes are never as large or hilly as their desert counterparts, but can still reach impressive heights of up 10d10 feet tall.

Area of Effect: Any sloping beach-adjacent land up to 1d10 miles long. It extends 1d3 miles inland. The further inland it goes, the taller and more strongly sloping the dunes get.

Difficult Terrain: Unless riding a mount, you move at half-speed when traveling across dunes more or less on an even level (or while descending a dune hill), or at one-third speed when climbing a dune hill.

Radiant Damage: If the dunes are in a hot climate or summer month in colder ones, this terrain deals 1 point of radiant damage to all living creatures exposed to them for every daylight hour they spend exposed to it between 10 am and 6 pm. For every 3 such hours of exposure (up to 2/day), you must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion and take 1d4 radiant damage from sunburn and the heat. Creatures with resistance to radiant damage are immune to these effects.

Slopes and Shrubbery: The further back from the beach, the taller the dunes rise and the more they feature thick swathes of hardy shrubbery. Shrubs provide half cover to kneeling Medium size creatures, or total cover when prone. They provide three-quarter cover to standing Small creatures and total cover when kneeling or prone. Large creatures gain no cover from them. These shrubs are extremely dry and flammable so that even 1 point of fire damage sets them ablaze, releasing thick, gray-white smoke in a 20 foot radius. Use stats for the fog cloud spell.

Slopes and Sinkholes: The slopes of coastal sand dunes are notoriously unstable and subject to collapse if subjected to even moderate stress (excluding normal creature movement). Any time an area effect attack or spell that deals bludgeoning, fire, force, lightning, or thunder damage is cast into, over, or around them, there is a 50% chance the slope falls apart. All creatures on it at the time must succeed at a DC 17 Dexterity save or fall from their current slope height into the newly opened sinkhole. You take half-damage from the fall due to the softer landing the sand provides, but are still knocked prone. If you succeed, you jump back and are standing adjacent to the sinkhole. If you take damage from any source while adjacent to the sinkhole, you must succeed at a DC 8 + damage dealt Dexterity save or be knocked into the sinkhole exactly as if you had failed your save when it was created. Creatures caught in the bottom of the sinkhole must make 3 consecutive DC 13 Dexterity saves in order to escape. Any failure sends you tumbling back to the sandy bottom to start over (no falling damage).

Fighting On a Slope: If you are descending a dune that slopes slightly down (or defending it against creatures trying to come up it), you gain a +1 bonus to attack and creatures below you suffer a -1 penalty to their attack. If you are descending a dune that slopes strongly down (or defending it against creatures trying to come up it), you gain a +2 bonus to attack and creatures below you suffer a -2 penalty to their attack.

Air, Earth, Radiant, and Water Magic: All air, earth, radiant, and water magic cast within coastal dunes has its DC increased by +1 and deals an extra 1d4 damage of its type on a failed save. In addition, its range is doubled. If the dunes are in a cold climate or winter months, then cold magic also gains these bonuses.

Tracking in Sand Dunes: Tracking in sand dunes gains advantage with no wind or suffers disadvantage with wind. Creatures with tremorsense ignore penalties.

Acid, Fire, and Poison Magic: All acid and fire magic cast within coastal dunes has its DC decreased by -1. In addition, its range is halved.

Lost to the Ages: Anything dropped on the ground is obscured by the sand, dust, or soil; it requires a DC 12 Perception check and 1d2 rounds to find. Any pits or other ground-based traps impose disadvantage to spot them. However, there is a 25% chance the trap does not activate due to the sand on top of it.

Duration: Permanent (more or less).

Note: Desert sand dunes favor air, earth, fire, poison, and radiant magic and penalize acid, cold, necrotic, and water magic. For sand dune (desert) rules, see Extreme Encounters: Radiant.

Sewer

Nonmagical, terrain, air, earth, poison, water, ground

This is a large underground network of interconnected shafts and tunnels used by a city as its sewer system. It is damp, foul, and full of poison and disease. It may intersect with a cave complex, dungeon, shrine, temple, or tomb, though these will almost always be blocked off or guarded.

Area of Effect: The size of the city, with hundreds of tunnels running in all directions. The sewer is usually restricted to one or two levels, but these stretch on for miles.

Difficult Terrain: You move at half-speed in this terrain. Any creature that has lived or worked in a sewer for at least a month as well as creatures who have spent all or most of their lives living underground (aberrations, drow, dwarves, oozes, etc.) move at normal speed.

Poison Damage: Due to being surrounded by the foul gasses, fluids, and worse, for every hour you spend in this terrain, you must succeed at a DC 13 Constitution save or suffer 1d4 points of poison damage and 1 level of exhaustion. If you end up in the water, the DC is increased +2.

Disease: For every day you spend in this terrain, you must succeed at a DC 11 Constitution save or be infected by sewer plague. If you end up in the water, the DC is increased +2.

Easy to Get Lost: Make a DC 13 Investigation, Nature, Perception, or Survival check to detect if a tunnel leads in the direction you want (including sloping up toward the surface or further down). As many tunnels look different when approached from the opposite direction, the DC increases to 15 to identify if you’ve been down this particular tunnel before. Some tunnels may be marked by signs and direction arrows, but the nature of the symbols the sewer workers used may not be obvious to those unfamiliar with them, especially if you do not share the same language. On average, it requires a DC 13 Intelligence or Wisdom check to correctly read signs in a sewer, or DC 15 if written in an unfamiliar language.

Fighting In Sewers: Due to the cramped conditions, all creatures not using natural weapons or Tiny to Medium melee weapons, suffer disadvantage to melee weapon attack rolls. If you take damage from any source while adjacent to a ledge where you could fall into the sewer water, you must succeed at a DC 8 + damage dealt Dexterity save or fall into the water.

Fighting On a Ramp or Sloping Shaft: If you are descending a ramp or tunnel that slopes slightly down (or defending it against creatures trying to come up it), you gain a +1 bonus to attack and creatures below you suffer a -1 penalty to their attack. If you are descending a ramp or tunnel that slopes strongly down (or defending it against creatures trying to come up it), you gain a +2 bonus to attack and creatures below you suffer a -2 penalty to their attack.

Fighting and Moving On a Ladder: There are numerous iron ladders you can ascend or descend, either to reach the surface or access the lower levels or pump stations. You move at onethird speed while climbing a ladder. While you are on a ladder, you suffer disadvantage on all attack, damage, saving throws, and skill checks.

Air, Earth, Necromancy, Poison, Water, and Web Magic: All such magic has its DC increased by +1 and deals an extra 1d4 poison damage on a failed save regardless of whether it normally deals poison damage.

Radiant Magic: All such magic has its DC reduced by -1 and its range is halved. The thick rock above insulates and interferes with radiant magic.

Tracking and Stealth: Tracking rolls suffer disadvantage unless the creature using the skill is a native to living underground. Stealth rolls gain advantage due to all the dripping and flowing water sounds, as well as the echoing nature of the stone tunnels making it difficult to pinpoint where sounds are coming from.

Duration: Permanent (until caved in).

Swamp

Nonmagical, terrain, acid, poison, water, ground-based

This is a swamp that may be foul and fetid or quite lovely in parts. There may be game trails, but no roads lead through this terrain. You can use this template for fens, marsh, moors, or any swampy area. Moors have less swamp, more fog.

Area of Effect: Any size swamp or wetland.

Difficult Terrain: You move at one-third speed in this terrain due to the partially flooded conditions, the underbrush, and low-hanging branches. Large mounts cannot be ridden here. If you Dash, fly, or run through this terrain, every round, you must make a DC 15 Dexterity save. If you fail, you have a 70% chance to trip over or run into roots, vines, or branches. You suffer 2 points of bludgeoning damage and are knocked prone. The other 30% chance is you run into a poison plant. You suffer 2 points of poison damage but may continue at your current speed. Natives move at half-speed and reduce their saving throw DC to 10 when moving faster. A “native” is any creature that has spent at least 6 months living in this or similar terrain, or was born here.

Swamp Fatigue: Due to fighting the swamp every step, for every hour you spend in this terrain, you must succeed at a DC 11 Constitution save or suffer 1 level of exhaustion. If this is a hot, humid swamp, or a bitter cold one in winter, then the DC is increased to 13.

Disease: For every day you spend in this terrain, you must succeed at a DC 11 Constitution save or be infected by sewer plague.

Easy to Get Lost: Make a DC 13 Nature, Perception, or Survival check to detect if the direction you’re heading leads in the direction you want. As many swamp areas look different when approached from a different direction, the DC increases to 15 to identify if you’ve been through this particular area of the swamp before.

Acid, Nature, Necrotic, Poison, Water, and Web Magic: All such magic has its DC increased by +1 and deals an extra 1d4 damage of its type on a failed save.

Fire, Lightning, and Radiant Magic: All such magic has its DC decreased by -1 and its range is halved.

Gator Bait: If you take damage from any source while adjacent to a bank, ledge, or slope where you could fall into the swamp water, you must succeed at a DC 8 + damage dealt Dexterity save or fall in in.

Passive Cover: All ranged weapon or spell attack rolls suffer a -2 penalty to hit. Due to how lush the terrain is, unless resting or stopped for any other reason, all creatures that are in motion are assumed to have half-cover.

Active Cover: You have total cover from ranged weapon and spell attack rolls if you are hidden behind a tree or (in many cases) when you are crawling along the jungle floor. You have three-quarter cover if you are mostly hidden behind a tree, only exposing yourself enough to spy, or to make a ranged weapon or any spell attack. You have half-cover if you are Small or Medium size and hiding behind bushes or other tall foliage, of which there is an abundance.

Note that area effect spells ignore bushes and may be able to wrap their damage around trees, or even destroy them. If an area effect spell deals enough damage to destroy the tree you are hiding behind, you take half damage (no save) from that spell instead. Trees of different ages and types will vary in hit points, but a good average is AC 13 (natural armor) and 50 hit points. Trees have damage resistance to bludgeoning and piercing damage and vulnerability to fire damage.

Tracking and Stealth: Tracking is normal, but Stealth rolls suffer disadvantage due to snapping twigs and rustling leaves, sloppy swampy soil, and/or moving through the water. Natives, beasts, fey, and plant creatures gain advantage.

Duration: Permanent (until dried up).

Waterfall

Nonmagical terrain, thunder, water, ground-based

This is a majestic waterfall in any climate. There is usually a relatively dry “secret” natural rock cave hidden in the cliff behind the waterfall. This could even be an entire cave complex (see Extreme Encounters: Earth for that template).

Area of Effect: Any river that falls over a cliff. The drop to the bottom of the falls can be anywhere from 50 feet for a small waterfall all the way up to the tallest in the world at 2,500 feet.

Recognize Danger: Make a DC 13 Perception, Nature, or Survival check to recognize the transition from normal to difficult terrain. If you are successful, and you are swimming or in a boat above the falls, you have 1d4+1 rounds to escape or prepare. If you are approaching the falls from below, the DC is only 10 and you may stop before entering the terrain.

Difficult Terrain: You move at half-speed when wading in the lake, river, or pool below the falls, or while directly under the waterfall. If you are swimming below the falls, you move at your normal swim speed unless directly under the waterfall, where you move at half-speed.

Force, Nature, Radiant, Thunder, and Water Magic: All such magic cast within 500 feet of the waterfall has its DC increased by +2 and deals an extra 1d6 damage of its type on a failed save. In addition, its range is doubled. If the beach is in a cold climate or in winter months, then cold spells also gain these bonuses.

Acid, Fire, Necrotic, and Poison Magic: All such magic within 500 feet of the waterfall has its DC reduced by -2. Its range is halved.

Lost to the Falls: Anything dropped into the water, whether above or below the falls, will eventually end up stuck at the bottom of the lake, washed ashore, or if the falls feed into a river, be swept away (GM’s choice). Any pits or other ground-based traps above or below the falls impose disadvantage to spot them.. However, there is a 25% chance the trap does not activate if it is underwater.

Tracking and Stealth: Tracking rolls are made as normal. Stealth rolls made within 500 feet of the falls (either above or below) gain advantage. Regardless of size, the falls are loud!

Duration: Permanent (unless river is dammed).

Options: Use mud or clay from Extreme Encounters: Earth for fighting on muddy shores surrounding the falls. You could also stack this template with rain, flood, or other weather. You may want to rule undead cannot cross running water (including waterfalls) except by way of a raft or other water vehicle.

Weather Events

Following are mundane, non-magical temporary weather events that could occur in any campaign setting.

Weather events are, by their nature, temporary. However, some events may last such long times they may be perceived as permanent to some.

Extreme Heat

Magical, weather, fire, ground-based

This area is permeated by supernatural, scorching heat. It may be the work of a god of fire, forge, or the sun, or the byproduct of a congregation of fire creatures such as devils, efreeti, fire giants, or salamanders, or it could be the result of an altar, artifact, idol, or relic.

  • Radiates: Evocation (fire) magic.
  • Area of Effect: Any, usually confined to a cave complex, crypt, dungeon, shrine, or tomb containing fire creatures.
  • Expanded Area of Effect: If you wish to expand the area of effect beyond its original borders to threaten a wider area, simply expand it by 90 feet per minute (1 mile per hour). This terrain can only potentially expand a number of miles equal to the CR of the primary monster or villain, or up to 1 mile for an idol or relic.
  • Perception: Make a DC 10 Perception, Nature, or Survival check to recognize the transition from normal to difficult terrain (or Arcana or Religion if fiends are present). If you succeed, you may stop before entering.
  • Dispel Magic: Refer to the Casting Dispel Magic Against Magical Terrain rules.
  • Difficult Terrain: Non-fire creatures move at half-speed as the combined heat and smoke sap your strength and make it difficult to breathe. Creatures that don’t need to breathe take a -5 foot penalty to speed (from the heat) instead.
  • Fire Damage: The terrain deals 1 point of fire damage to all non-fire creatures for every 1 minute they remain inside. For every 10 minutes, they must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion and take 1d6 fire damage from smoke inhalation. Creatures with resistance to fire damage are immune to these effects. Creatures who do not need to breathe do not take the extra fire damage or exhaustion.
  • Doubling of the Light: All nonmagical fire (torches, etc.) have their bright and dim light doubled (and so burn twice as fast).
  • Tracking: Tracking rolls suffer a -2 penalty.
  • Fire Magic: All fire magic has its DC increased by +2 and deals an extra 1d6 fire damage regardless of whether the save is successful or not. In addition, the range of fire magic is doubled.
  • Cold and Water Magic: All such magic has its DC decreased by -2.
  • Ranged Attack Penalty: Due to the shimmering air and smoke, as well as the flying cinders, all ranged weapon and spells by non-fire creatures suffer disadvantage to attack rolls.
  • Smoke Screen: Anything dropped on the ground is obscured by the smoke and soot; it requires a DC 13 Perception check to find. If you fail the check, you accidentally touch embers and take 1 point of fire damage. Any pits, trip wires, or other ground-based traps require a DC 15 Perception check to spot.
  • Boss Fight: When the party confronts the primary monster or villain in this area, the unnatural heat intensifies. Living or non-fire creatures within 30 feet of the primary monster or villain take 1 point of fire damage per round instead of every minute. This damage is in addition to any similar abilities, traits, or powers the monster or villain has. Living or non-fire creatures within 5 feet of it take 2 points of fire damage per round instead. Creatures with resistance to fire take no damage unless they come within 5 feet of it; at that point, they take 1 point of fire damage for each round they remain adjacent.
  • Terrain Anchor: If an altar, artifact, idol, or relic is causing the terrain, it has AC 10 and 120 hit points. It is immune to fire, necrotic, poison, and psychic damage, and has resistance to all other damage types. It deals 4d4 fire damage per round to any non-fire creature touching it. Any creature killed by the idol or relic turns to hot ash and cinders. The ashes blow away in 2d4 rounds if not scooped up and saved.
  • Duration: The terrain ends 1d12 hours after the primary monster or villain is driven out or destroyed, and/or the cause for the terrain is removed or destroyed (such as an idol or relic).

If the primary monster or villain and/or cause for the terrain returns to the area, all terrain effects resume as before. However, the area of effect is reduced to half its original radius, centered on the primary monster, villain or cause. The area of effect increases by 10% per hour until it occupies its original radius.

Fire Devil

Nonmagical, terrain, air, fire, weather-based

This is a rare to very rare form of tornado full of whirling ash and flame from a large fire source. It is also known as a firenado, fire tornado, fire twister, or fire whirl. It is formed when high wind meet a firestorm, volcanic eruption, or wildfire.

  • Area of Effect: 1d6 x 10 foot cylinder (rare) or 0.5-1 mile tall cylinder (very rare). The smaller rare ones are only 5 feet wide, while the very rare large ones can be 1d4 x 10 feet wide.
  • Speed: Rare fire devils move 30 feet per round and very rare ones move 60 feet per round.
  • Recognize Danger: Make a DC 10 Perception or Survival check to smell smoke and/or see the flames before they arrive. If you are successful, you have 1d4+1 rounds to escape before the fire devil arrives.
  • Difficult Terrain: You move at half-speed in this terrain as the smoke and fire obstruct you.
  • Fire Damage: This terrain deals 1 point of fire damage to all non-fire creatures for every round you remain exposed to it. For every 10 minutes, you must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion and take 1d6 fire damage from smoke inhalation. Creatures with resistance to fire are immune to these damage and exhaustion effects.
  • Air and Fire Magic (Rare): All air and fire magic in a rare fire devil has its DC increased by +1 and deals an extra 1d4 damage of its type on a failed save. In addition, the range of air and fire magic cast within 120 feet of the fire devil is doubled.
  • Air and Fire Magic (Very Rare): All air and fire magic in a very rare fire devil has its DC increased by +2 and deals an extra 1d6 damage of its type regardless of whether the save is successful or not. In addition, the range of air and fire magic cast within 240 feet of the fire devil is tripled.
  • Cold and Water Magic (Rare): All such magic cast within 120 feet of a rare fire devil has its DC decreased by -1. In addition, its range is halved.
  • Cold and Water Magic (Very Rare): All such magic cast within 240 feet of a very rare fire devil has its DC decreased by -2. In addition, its range is halved.
  • Ranged Attack Penalty: Due to the shimmering air and smoke, as well as the flying cinders, all ranged weapon and spells by non-fire creatures suffer disadvantage to attack rolls.
  • Cover: Any creature behind the fire devil has total cover and any creature off to one side of it by 5-10 feet has three-quarters cover. Nonmagical items as well as any spells or spell-like abilities meant to pass through a fire devil are consumed and destroyed by it instead.
  • Duration: 1d4 minutes for the rare small ones, or 1d2 x 10 minutes for the larger very rare ones.

Firestorm

Nonmagical terrain, air, fire, weather-based

A firestorm is a fire of such intensity it creates its own wind system of storm-like proportions. It is most often formed from a wildfire, and typically requires at least a half-mile of fire to be created. It has a 50% chance per minute to create 1d4+1 fire devils.

  • Area of Effect: 1d8 mile tall by 1d8 mile wide radius sphere.
  • Speed: A firestorm begins in a 240 foot radius sphere and expands 240 feet per round in all directions until it reaches its maximum width.
  • Recognize Danger: Make a DC 13 Perception or Survival check to hear, smell, and/or see the firestorm before it arrives. If you are successful, and depending on your proximity to its point of origin, you have 1d4+1 rounds (on average) to escape or find shelter before the firestorm arrives.
  • Difficult Terrain: You move at one-third speed inside this terrain as the smoke and fire whirl viciously all around you.
  • Fire Damage: This terrain deals 10d10 points of fire damage and 2 levels of exhaustion to non-fire creatures for every round they remain inside it. Non-fire creatures inside the firestorm who make a successful DC 20 Dexterity saving throw take half damage and exhaustion. Non-fire creatures within 240 feet outside the firestorm suffer 10 points of fire damage and 1 level of exhaustion. Non-fire creatures within 500 feet of the firestorm take 5 points of fire damage. Non-fire creatures outside the firestorm but within 500 feet who make a successful DC 17 Dexterity saving throw take half damage.
  • Air and Fire Magic: All such magic cast within 1 mile of a firestorm has its DC increased by +4 and deals an extra 2d10 damage regardless of whether the save is successful or not. In addition, the range of such magic is tripled.
  • Cold and Water Magic: All such magic cast within 1 mile of a firestorm has its DC decreased by -2. In addition, its range is halved.
  • Tracking During a Fire Devil
  • Tracking during a fire devil suffers disadvantage.
  • Fire creatures gain advantage instead.
  • Ranged Attack Penalty: Due to the shimmering air and smoke, as well as the flying cinders, all ranged weapon and spells by non-fire creatures suffer disadvantage to attack rolls.
  • Tracking: Tracking is impossible in a firestorm to non-fire creatures. Fire creatures suffer disadvantage when tracking inside the firestorm.
  • Duration: 1d4 minutes before it burns itself out. Any fire devils spawned by it remain until they burn out (always within a few minutes).

Flood

Nonmagical terrain, force, necrotic, thunder, water, ground-based

Excessive rainfall, snow melt, or broken dams can cause lakes, oceans, or rivers to overflow, resulting in floods that wreak havoc and misery.

Area of Effect: Any, up to 6d10 miles inland from the water source, and 3d10 miles wide. The depth usually varies from 1d10 feet deep.

Recognize Danger: Make a DC 13 Perception, Nature, or Survival check to recognize the impending danger. If you succeed, you have 1d6 hours to escape or find shelter before the flood.

Raging Waters: A large, heavy flood (such as when a dam breaks) can wield incredible destructive power. For the first 5 rounds it hits, it deals 5d10 bludgeoning damage to creatures, objects, and structures directly in its path, and 3d10 bludgeoning damage to anything within 1 mile to either side. Those that make a successful DC 15 Dexterity save only suffer half-damage. Anything incapacitated, killed, or destroyed by this is swept away 1d6 miles.

Difficult Terrain: You move at one-third speed in this terrain as water and debris slow you. You move at half-speed when using a Large mount; Medium and Small mounts cannot be used.

Radiant Damage: If the flood zone is in a hot climate or a summer month in colder ones, this terrain deals 1 point of radiant damage to all living creatures for every daylight hour they spend exposed to it between 10 am and 6 pm. For every 3 such hours of exposure (up to 2/day), you must make a DC 13 Constitution saving throw or suffer 1 level of exhaustion and take 1d4 radiant damage from sunburn and the heat. Creatures with resistance to radiant damage are immune to these damage and exhaustion effects.

Flood Fatigue: For every hour you spend in this terrain, you must make a DC 13 Constitution saving throw or suffer 1 level of exhaustion from trudging or rowing through the flood.

Waterborne Disease: For every day you spend in this terrain, you must make a DC 11 Constitution saving throw or be infected with sewer plague (cholera, malaria, etc.), which is spread by mosquitos and/or the water even without sewers. If in a city with a sewer, raise the save to DC 13.

Force, Necrotic, Thunder, and Water Magic: All such magic has its DC increased by +2 and deals an extra 1d6 damage of its type on an unsuccessful save. In addition, its range is doubled. If the flood is in a cold climate or during winter months, then cold spells also gain these bonuses.

Acid and Fire Magic: All such magic within 1 mile of the flood zone has its DC reduced by -2. Its range is halved.

Melee Attack Penalty: When fighting in water up to waist-high, non-aquatic creatures suffer a -2 penalty to melee weapon and spell attacks. When fighting in water up to chest-high, non-aquatic creatures suffer disadvantage to melee weapon and spell attacks.

Don’t Fall In!: If you take damage from any source while adjacent to a bank, ledge, or slope where you could fall into the flood water, you must succeed at a DC 8 + (damage dealt) Dexterity save or fall into the water.

Lost to the Flood: Anything dropped in the flood is lost for good unless you spend 1d4+1 rounds to recover it and succeed at a DC 15 Dexterity save, or 1d4+2 rounds if the flood water is taller than you are. Ground-based traps will fail to trigger unless unaffected by water. The DC to spot traps underwater is increased by +5.

Stealth: Stealth rolls by non-aquatic creatures suffer disadvantage regardless of water depth since you must displace water to move.

Duration: 1d2 days at minimum for the waters to recede (taking any dropped items and unsecured objects with it). The average is 1d2 weeks, or up to 1d2+2 weeks in the worst cases.

High Elevation

Nonmagical terrain, air, cold, force, radiant, ground-based

Areas 2,500+ feet above sea level create stress on non-native beasts and humanoids. Humans in particular cannot live more than a number of days equal to their Constitution modifier (minimum of 1) at elevations of 20,000 feet or more (like Mount Everest), and no permanent human settlements exist at these heights.

  • Area of Effect: Any, usually hills or mountains, but also cloud castles, floating sky islands, etc.
  • Recognize Danger: Make a DC 13 Perception, Nature, or Survival check to recognize the impending transition from normal to difficult terrain. If you succeed, you can stop before entering.
  • Difficult Terrain: Until you adapt, you move at half-speed in this terrain as the thinner air slows you and makes you tire easily.
  • Thin Air: This terrain deals 1 level of exhaustion for every 3 days you spend in it if you fail a DC 13 Constitution save. Once you accumulate 3 levels of exhaustion, you suffer altitude sickness (see below) and your body can never adapt to this terrain or similar terrain like Cloud Castle.
  • Altitude Training: If you spend 15 days at high elevation without accumulating 3 levels of exhaustion, your body adapts and becomes immune to altitude sickness. You no longer need to make saving throws against thin air. After you adapt to this terrain and while you remain in it, you gain a +2 bonus to Initiative, Dexterity, and Constitution saves, as well as advantage to jump checks and a +2 bonus to any similar short, explosive physical action that requires an Athletics, Acrobatics, or Strength check or save (such as to shove, or to escape a grapple). In addition, you gain a +10 bonus to speed when you run short distances (up to 1,000 feet) or perform the Dash action. However, you suffer disadvantage to Athletics, Acrobatics, or Strength checks or saves for sustained physical activity due to being in a low-oxygen environment. Once you return to a lower elevation, you retain all bonuses gained at high elevation for 14 days + your Constitution modifier (minimum of 1). During this readjustment phase, the -4 penalty for sustained Athletics, Acrobatics, and Strength checks or saves is replaced by a +2 bonus instead. After your body completes its readjustment in 2 weeks + 1d4 days, all your thin air bonuses and penalties are gone, and you return to normal. You may return to any high elevation terrain afterward and only require 3 days for your body to readjust before you regain all the bonuses and penalties, with no need to save against thin air.
  • Altitude Sickness: If you fail to adjust to thin air, you develop altitude sickness and act as if poisoned as long as you remain at high altitude. In addition, you must continue to make a DC 13 Constitution save daily. If you fail, you suffer another level of exhaustion. If you miss your save by 5 or more, you are incapacitated for 24 hours. If you roll a 1, you die. The DC 13 only applies at elevations of 2,500 feet. For every 500 feet above that, the DC increases by +1. Most human settlements are not built higher than 3,500 feet above sea level. Birds (including birdlike humanoids), dwarves, rock gnomes, giants, and beasts or creatures native to high elevations are immune to altitude sickness, as are any creatures who were born, raised, and/or spent time training in this terrain.
  • Air, Cold, Force, Lightning, Radiant, and Thunder Magic: All such magic has its DC increased by +2 and deals an extra 1d4 damage of its type on a failed saving throw. Its range is doubled. This is due to being closer to the sky.
  • Conjuration and Teleportation Magic: The range, distance, and duration of movement and teleportation-based effects is doubled. This includes feather fall, fly, haste, jump, levitate, longstrider, misty step, slow, spider climb, teleport, etc.
  • Fire and Necromancy Magic: All such magic has its DC reduced by -2. Its range is halved. In addition, whenever a fire or necromancy spell or spell-like ability is used in this terrain, the caster must make a DC 15 Arcana or Religion check. If the check fails, the spell fizzles and is lost. If it succeeds, the caster suffers 1 level of exhaustion for wrestling against the high altitude’s thinner air.
  • Dying of the Light: All nonmagical fires have their bright and dim light reduced by half.
  • Duration: Permanent.

Lava Flow

Nonmagical terrain, fire, ground-based

This is an active lake, pool, or river of flowing molten lava from a volcano or other heat source.

  • Area of Effect: 1d6+1 miles unless stopped.
  • Speed: A flow moves 30 feet per round unless blocked by stone (which it goes around) or a lake, river, or ocean, which slows its speed by half.
  • Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to hear, smell, and/or see the lava flow before it arrives. If you are successful, and depending on your proximity to it, you have 2d6+3 minutes (on average) to escape or find shelter before it enters the area.
  • Difficult Terrain: You cannot move through this terrain unless you have immunity to fire damage. If you do, you move at one-third speed inside it.
  • Fire Damage: This terrain deals 10d10 points of fire damage to non-fire creatures for every round they remain inside it. Non-fire creatures within 15 feet of either side of the lava flow suffer 1d4+1 points of fire damage from the intense heat and smoke. A lava flow deals 10d10 points of fire damage per round to flammable objects in its path; Large objects may briefly slow it for 1d2 rounds.
  • Fire Magic: All fire magic has its DC increased by +2 and deals an extra 1d8 fire damage regardless of whether the save is successful for not. In addition, the range of fire magic cast within 1,000 feet of the lava flow is doubled.
  • Cold and Water Magic: All such magic cast within 500 feet of an active lave flow has its DC decreased by -2. In addition, its range is halved.
  • Tracking: Tracking is impossible in a lava flow. Tracking on either side of the lava flow is normal.
  • Ranged Attack Penalty: Due to the hazy air and smoke, all ranged weapon and spells by non-fire creatures in, on, over, or around an active lava flow suffer disadvantage to attack rolls.
  • Lava Screen: Anything dropped on the ground is obscured by ash; it requires a successful DC 15 Perception check and 1d4 rounds to find. Anything dropped into the lava that is not magical is immediately destroyed. Any pits, trip wires, or other ground-based traps impose disadvantage to spot them. However, there is a 50% chance the trap does not activate due to the ash or lava on top of it.
  • Duration: Permanent. If not actively fed by fresh lava, a flow can cool enough to form a walkable crust in 10-15 minutes. However, the area below the crust can take as long as 180 days to cool down. Depending on its depth, it could take 30 years or more to cool down at its lowest point.

Once an active lava flow cools down and drains out, it can leave behind up to 1d6+1 miles of empty lava tubes of volcanic rock that form a cave complex. These tubes vary in size, but most consist of a Large tube with a network of many Small to Medium tubes branching off it.

Lava tubes are difficult terrain, and due to the unique composition of volcanic rock, all radiant spell damage and range is halved inside them.

Poisonous Vapors

Nonmagical, terrain, air, poison, water, airborne

This area is filled with poisonous, translucent vapor. It could be a natural byproduct of poison creating creatures like aberrations, green dragons, hags, oozes, or plants, or the aftermath of a failed alchemical experiment or conjuration spell.

Area of Effect: Any, usually confined to a cave complex, shrine, or tunnels containing aberrations, oozes, or poison-producing creatures.

How to Remove It: The vapors can be dispersed by any high wind, whether magical (such as gust of wind), or nonmagical means.

Recognize Danger: Make a DC 13 Perception, Nature, or Survival check to recognize the transition from normal to difficult terrain. If you succeed, you may stop before entering.

Difficult Terrain: You move at half-speed in this terrain as the poison vapors sting your eyes, your skin, and your lungs, making every breath you draw an agony. You need to spend a minute to rinse your eyes, nose, and mouth out when you exit the vapors, or else you take 1d2 extra points of poison damage (no save) as the poison works its way out of your system on its own. Aberrations, hags, and oozes are immune.

Poison Damage: This terrain deals 1 point of poison damage per minute to non-aberrations.

Ideas: Poison rain could be the result of a green dragon seeding a cloud with its poison chlorine breath, the revenge of evil druids or hags on a farming village to ruin their crops, the aftermath from an alchemical or conjuration experiment, an evil sign or ill omen, etc. and non-oozes and objects that enter its area of effect. In addition, for every 10 minutes creatures are inside the vapors, they must make a DC 15 Constitution saving throw or become poisoned until they either exit the area or spend an action to cough and wash their eyes out. Aberrations, hags, oozes, and creatures with resistance to poison are immune to these ongoing effects.

Air, Poison, and Water Magic: All air, poison, and water magic has its DC increased by +1 and deals an extra 1d6 poison damage on a failed save regardless of whether it normally deals poison damage or not. In addition, its range is doubled.

Ruined Crops: After 10 minutes of exposure, any crops (fruits, grains, etc.) left in these vapors become poisonous, though they may not display any obvious signs. Any creature that eats poisoned crops must succeed at a DC 13 Constitution save or be poisoned for 2d4 days.

Hard to See: Any pits, pressure plates, trip wires, or ground-level traps in the vapors increase the DC to spot them by +1.

Duration: Permanent, as long as whatever is producing the vapors is still in the area and the vapors have nowhere to escape to. Otherwise, the vapors disperse in 2d4 x 10 minutes, unless a high wind comes along, in which case they disperse in 1d4+1 rounds. With only a light wind, they disperse in 2d4+2 rounds.

Rain (Normal)

Nonmagical terrain, thunder, water, ground-based

This is light or heavy rainfall over any terrain.

This is the most versatile of all our templates; you can use it with almost all of them, and as often as you want. Nothing says “grimdark” or communicates sorrow or despair like rain!

Area of Effect: Any, up to 10d10 mile wide, stratosphere high cylinder.

Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the transition from normal to difficult terrain. If you are successful, you have 1d10 minutes to escape or find shelter.

Difficult Terrain: You move at normal speed in a light rain. Unless riding a mount, you move at half-speed in heavy rain.

Fighting On a Wet Ramp, Stairs, or Sloping Shaft: If you are descending a ramp, stairs, or tunnel that slopes slightly down (or defending it against creatures trying to come up it), you gain a +1 bonus to attack and creatures below you suffer a -1 penalty to their attack. If you are descending a ramp, stairs, or tunnel that slopes strongly down (or defending it against creatures trying to come up it), you gain a +2 bonus to attack and creatures below you suffer a -2 penalty to their attack.

Air, Lightning, Thunder, and Water Magic: All such magic has its DC increased by +1 and deals an extra 1d4 damage of its type on a failed save. In addition, its range is doubled. If the rain is in a cold climate or in winter months, then cold spells also gain this.

Acid, Fire, Necrotic, and Poison Magic: All such magic within the rain has its DC reduced by -1. Its range is halved.

Missile Weapons In the Rain: Bows cannot be used in heavy rain, and only for 2d4 rounds in light rain before the string gets too wet to use. Crossbows and other missile weapons may be used in both light or heavy rain.

Ranged Attack Penalty: All non-aquatic creatures suffer a -2 penalty to ranged weapon and spell attack rolls during a heavy rain. In addition, the range of thrown weapons in a heavy rain is halved.

Stealth: Stealth rolls in light rain gain a +2 bonus. Stealth rolls in heavy rain gain advantage.

Duration: 1d4 hours, with a 50% chance the rain repeat in 1d4 hours, with a 25% chance light rain turns to heavy rain or vice versa.

Option: 1 hour into a heavy rain, you may wish to stack this template with the mud or clay template from Extreme Encounters: Earth.

Tracking In the Rain: Tracking in light rain suffers a -2 penalty while tracking in heavy rain suffers disadvantage.

Melee and Ranged Attack Penalty: Due to the bumpy ride, all creatures in water vehicles suffer disadvantage to both melee and ranged weapon and spell attack rolls.

Lost to the Rapids: Anything dropped into the rapids is swept away and lost. Traps in the rapids impose disadvantage to spot them.

Tracking and Stealth: Tracking and Stealth rolls are impossible in the rapids themselves except for aquatic creatures, but they still suffer disadvantage to their rolls.

Duration: Permanent.

Note: You may want to use the waterfall template for when the party comes to the end of their journey… literally.

GM Advice: If you’ve ever watched Deliverance or The River Wild, then you know what to do with this template! I can hear the banjos now…

Tracking in a Flood: Tracking in a flood suffers disadvantage (assuming there is no clear movement in the water to follow, then reduce to -2). Aquatic creatures ignore these penalties.

Tracking on a Beach: Tracking on sandy beaches gains advantage with no wind or in wet sand, but suffers disadvantage with wind or after the ride comes in (if tracks are in the tidal zone. Creatures with tremorsense ignore these penalties. Tracking on rocky beaches suffers a -2 penalty. Creatures with tremorsense ignore this penalty.

Rain (Poison)

Nonmagical terrain, air, poison, water, weather-based

There’s an awful smell like chlorine in the air.

The clouds turn a sickly, venomous shade of green. Poison rain falls from the sky, hitting the ground in toxic splats. Just a few drops at first, then a storm that poisons creatures and crops.

Area of Effect: Any, usually confined to a 4d6 mile radius.

How to Remove It: A control weather spell or similar magic can remove poison rain.

Recognize Danger: Make a DC 13 Perception, Nature, or Survival check to recognize the transition from normal to difficult terrain. If you succeed, you have 1d6+1 rounds to exit the area (if possible) or find shelter before the rain hits.

Difficult Terrain: The poison does not create difficult terrain while it rains. Instead, it remains on the ground afterward and presents a danger to those walking or riding mounts. Poison may seep into badly stitched or damaged footwear, through bare skin, paws, or hooves (shod or unshod). Creatures moving over the poisonous puddles left behind by the rain must make a DC 10 Constitution save or be poisoned for 1d4 hours. The poison dries up in 1d3 days. Add +2 days if sleet or snow falls, or -2 days (minimum of 0) with ordinary rain.

Poison Damage: This terrain deals 1 point of poison damage per minute to creatures and crops (but not objects) that enter its area of effect. In addition, for every 10 minutes creatures are exposed to the rain, they must make a DC 13 Constitution saving throw or become poisoned for 1d4 hours. You need to spend a minute to rinse your eyes, nose, mouth, clothes, and gear when you exit the rain, or else you take 1d2 extra points of poison damage (no save). Aberrations, fey, oozes, and creatures with resistance to poison are immune to these effects.

Poison and Water Magic: All poison and water magic has its DC increased by +1 and deals an extra 1d4 poison damage on a failed save regardless of whether it normally deals poison damage. In addition, its range is tripled.

Ruined Crops: After 10 minutes of exposure, any crops (fruits, grains, etc.) left in this rain become poisonous, though they may not display any obvious signs. Any creature that eats poisoned crops must succeed at a DC 13 Constitution save or be poisoned for 2d4 days.

Tracking and Stealth: Rolls made as normal.

Duration: 1d4 hours.

Storm at Sea

Nonmagical terrain, thunder, water, ground-based

What could be more cinematic than to endure a storm or other rough weather during a long sea voyage? This template simulates the effect weather has on creatures aboard the ship, but does not take into account the specifics of that weather. You should stack this template with a rain (light or heavy) at minimum, or lightning, thunder, or windstorms from Extreme Encounters: Air.

Area of Effect: Any size water vehicle.

Recognize Danger: Make a DC 15 Perception, Nature, or Survival check to recognize the transition from normal to difficult terrain. If you are successful, you cannot avoid it, but have 1d6x10 minutes to “batten down the hatches” and prepare. If your check succeeds by 5 or more, you may change course to avoid the weather entirely; however, this may put you well off-course and so this is not preferred for time-sensitive voyages.

Difficult Terrain: You move at half-speed in a ship during normal rough weather (choppy waves and light or heavy rain). You move at one-third speed in a storm (tall, violent waves that wash over the deck along with being battered by heavy rain, thunder, lightning, and/or wind, etc).

Radiant Damage: If the ship is in a hot climate or summer month in colder ones, this terrain deals 1 point of radiant damage to all living creatures above decks for every daylight hour they spend exposed to it between 10 am and 6 pm. For every 3 such hours of exposure (up to 2/ day), you must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion and take 1d4 radiant damage from sunburn and the heat. Creatures with resistance to radiant damage are immune to these ongoing effects.

Sea Sickness: For every day you spend aboard a ship in calm weather, you must succeed at a DC 13 Constitution save or you become sea sick. The DC increases to 15 in rough weather (heavy rain) or DC 17 in any storm. If you fail, you react as if you were poisoned and must make a DC 13 Constitution save every hour or spend 1d10 minutes vomiting, during which you are incapacitated. Creatures with resistance to poison are immune to these effects, as is any creature with a nautical background, or who succeeds at 3 consecutive saving throws against being sea sick.

Hats and Protective Head Gear: When wearing a hat or similar protective head gear, you automatically make your first saving throw against radiant damage and exhaustion due to sun exposure in hot climates or weather.

Air, Force, Lightning, Radiant, Thunder, and Water Magic: All such magic has its DC increased by +2 within the ocean, and deals an extra 1d6 damage of its type on a failed save. In addition, its range is doubled. If the ship is sailing in a cold climate or during winter months, then cold spells also gain these bonuses.

Acid, Earth, and Poison Magic: All such magic within the ocean has its DC reduced by -2. Its range is halved.

Initiative Penalty: Due to the constant sway of the ship, all non-aquatic creatures or those without a nautical background suffer a -2 penalty to Initiative rolls during calm weather or light rain, or disadvantage during heavy rain or a storm.

Fighting Above Decks: Due to the sway of the ship, all non-aquatic or non-nautical background creatures suffer a -2 penalty to both melee and ranged weapon and spell attack rolls against other creatures during calm weather or light rain, or disadvantage during rough weather (heavy rain) or a storm.

Fighting Below Decks: Due to the cramped conditions in addition to the sway of the ship, only Tiny or Small melee weapons can be used.

Lashed by Waves: During a storm, waves over the sides of the ship. If you are above deck, every 1d4 rounds, you must succeed at a DC 15 Dexterity save or be shoved 20 feet in a straight line toward the other side of the ship and knocked prone. If this is enough to place you off the ship, you are shoved overboard. To determine the direction shoved, roll a d4 and use these results: 1 = North, 2 = East, 3 = South, 4 = West.

Lost to the Deep: Anything dropped into the ocean is usually lost forever (GM’s choice).

Tracking and Stealth: Tracking and Stealth rolls are made as normal when the sea is calm. Tracking suffers disadvantage during rough weather but Stealth gains advantage. This applies to using both skills against other ships as well as against creatures on your ship.

Duration: Length of storm or rough weather.

Storm (Lightning)

Nonmagical, air, lightning, thunder, weather-based

The sky turns black with roiling storm clouds accompanied by bolts of lightning and raging thunder. This is a more or less “dry” storm with little to no rain; it has low winds in summer and high winds in spring or fall.

  • Area of Effect: 1,200 (4d6 x 100) miles.
  • Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the impending transition from thunder storm to lightning storm. If successful, you have 1d3 x10 minutes to find shelter before the first lightning hits.
  • Difficult Terrain: You move at half-speed if this storm is accompanied by high winds. You move normally if there are low winds.
  • Storm Fatigue: For every hour you remain exposed to this storm, you must make a DC 13 Wisdom saving throw or suffer 1 level of exhaustion due to anxiety. Air elementals, nonliving creatures, and those with resistance or immunity to lightning or thunder damage are immune to these ongoing exhaustion effects.
  • High Wind Warning: For every 10 minutes you spend exposed to this storm if it has high winds, make a DC 10 Dexterity saving throw. If you fail, the wind knocks debris into you that deals 1d4 bludgeoning damage.
  • Storm Warning: For every hour you spend exposed to this storm, you must make a DC 10 Dexterity save. If wearing metal armor, the DC increases to 13. If you fail, you are hit by a lightning bolt (as if by the spell) that deals 8d6 lightning damage and knocks you prone. If you fail your save by 5 or more, the lightning bolt arcs and hits an adjacent creature within 5 feet of you for 2d6 lightning damage (4d6 if that creature is wearing metal armor). If you roll a 1, the bolt hits 2 adjacent creatures. Adjacent creatures are allowed a DC 13 Dexterity saving throw for half-damage (or DC 15 if wearing metal armor).
  • Height of the Storm: If any 3rd level or higher lightning magic (call lightning, lightning bolt, chain lightning, etc.) is used within this storm, the random lightning strikes from storm warning increase and intensify in a 240 foot radius around the caster on the round after the triggering spell. All creatures within range other than the caster must succeed at a DC 15 Dexterity save or be hit by a 3d10 bolt as if by a call lightning spell. The caster has no control over who the storm hits.
  • Storm Magic: All air, lightning, and thunder magic has its DC increased by +2 and deals an extra 1d6 damage of its type regardless of whether the saving throw is successful or not.
  • Fire Magic: If the storm has high winds, all fire magic within the storm has its DC reduced by -2, and any damage dealt is reduced by 1d6 on a successful save. If the storm has low winds and/or light rain, the DC is reduced to -1 and the damage is reduced by 1d4 instead.
  • Force and Water Magic: All force and water magic within the storm has its DC reduced by -2. This is because the storm siphons off part of these magics to feed itself.
  • Ranged Attack Penalty: If the storm has high winds (regardless of rain), all living or non-air/ storm creatures suffer disadvantage to ranged weapon and spell attacks. If the storm has low winds and/or light rain, the penalty is only -2.
  • Dying of the Light: If the storm has high winds and/or light rain, all nonmagical fires have their bright and dim light reduced by half.
  • Stealth: Stealth rolls made during this storm are made with advantage.
  • Duration: 1d2 hours. Note that the thunderstorm the lightning grew from lasts up to 1d4 hours before the lightning starts and after it ends.
  • Note: You must stack and overlap this template on top of the thunderstorm, but not vice versa.

Storm (Thunder)

Nonmagical, air, lightning, thunder, weather-based

The sky turns black with roiling storm clouds accompanied by rumbling thunder. This is a more or less “dry” storm with little to no rain; it has low winds in summer and high winds in spring or fall. You may stack a lightning storm on top of this template. For a wet storm, use the rain (light or heavy) or winter storm.

  • Area of Effect: 1,200 (4d6 x 100) miles.
  • Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the impending storm. If successful, you have 1d3 x10 minutes to find shelter before the storm hits.
  • Difficult Terrain: You move at half-speed if this storm is accompanied by high winds. You move normally if there are low winds.

Tracking: Tracking in a lightning or thunderstorm suffers disadvantage. Reliable hearing is limited to 30 feet in high winds, and words are snatched away unless shouted.

Air- and storm-based creatures are immune to these penalties. Nonliving creatures (constructs, undead) reduce the penalty to -2.

  • Storm Fatigue: For every hour you remain exposed to this storm, you must make a DC 13 Wisdom saving throw or suffer 1 level of exhaustion due to anxiety. Air elementals, nonliving creatures, and those with resistance or immunity to lightning or thunder damage are immune to these ongoing exhaustion effects.
  • High Wind Warning: For every 10 minutes you spend exposed to this storm, make a DC 10 Dexterity saving throw. If you fail, the wind knocks debris into you that deals 1d4 bludgeoning damage.
  • Height of Thunder: If any 2nd level or higher thunder magic (shatter, etc.) is used within this storm, all creatures within 240 feet other than the caster who triggered this must succeed at a DC 13 Dexterity save or be hit by a thunderwave spell for 2d8 thunder damage. The caster has no control over who the storm hits.
  • Storm Magic: All air, lightning, and thunder magic has its DC increased by +1 and deals an extra 1d4 damage of its type regardless of whether the saving throw is successful or not.
  • Fire Magic: If the storm has high winds, all fire magic within the storm has its DC reduced by -1, and any damage dealt is reduced by 1d4 on a successful save. If the storm has low winds and/or light rain, the DC is not increased and the damage is reduced by 1d2 instead.
  • Force and Water Magic: All force and water magic within the storm has its DC reduced by -1, and any damage dealt is reduced by 1d4 on a successful save. This is because the storm siphons off part of these magics to feed itself.
  • Ranged Attack Penalty: If the storm has high winds (regardless of rain), all living or non-air/ storm creatures suffer disadvantage to ranged weapon and spell attacks. If the storm has low winds and/or light rain, the penalty is only -2.
  • Dying of the Light: If the storm has high winds and/or light rain, all nonmagical fires have their bright and dim light reduced by half.
  • Stealth: Stealth rolls made during this storm are made with advantage.
  • Duration: 2d4 hours. Note that if you stack a lightning storm template on top of a thunderstorm, the thunderstorm lasts up to 1d4 hours before the lightning starts and after it ends. The thunder and lightning durations overlap.

Volcano/Volcanic Event

Nonmagical terrain, earth, fire, thunder, ground-based

A mountain erupts in a terrifying shower of ash, smoke, and lava. There may be tremors for days before or little to no warning at all (maybe a few hours). Stack the lava flow template on top of this terrain if desired. You could also stack the firestorm and/or fire devil templates on too.

  • Area of Effect: 120 mile wide and stratosphere-high cylinder.
  • Recognize Danger: Make a DC 17 Perception, Nature, or Survival check to sense the impending eruption through the tremors and your sixth sense. If you have tremorsense, you gain advantage to your check. If you are successful, you have 1d3 x 10 minutes to escape or find shelter.
  • Difficult Terrain: You move at half-speed in this terrain due to the tremors, as well as the smoke and shower of hot ash and debris.
  • Thunder Damage: This terrain deals 1 point of thunder damage to all non-earth or non-fire creatures in the first 3 rounds it erupts. It deals 5d10 thunder damage to all buildings and other nonmagical objects in a 20 mile radius.
  • Fire Damage: For the first 1d6+1 days, for every hour you are out in the open within 20 miles of the volcano, you must make a DC 15 Constitution saving throw or suffer 1d6 fire damage and 1 level of exhaustion from breathing in hot ash and smoke. Creatures with resistance to fire are immune to these effects.
  • Earth, Fire, and Thunder Magic: All earth, fire, and thunder magic cast within 20 miles of an eruption has its DC increased by +4 and deals an extra 1d10 damage regardless of whether the save is successful or not. In addition, the range of earth, fire, and thunder magic is tripled.
  • Cold and Water Magic: All cold and water magic cast within 20 miles of an erupting volcano has its DC decreased by -2. In addition, its range is halved.
  • Ranged Attack Penalty: Due to the shimmering air, smoke, and flying cinders, all ranged weapon and spells by non-fire creatures suffer a -2 penalty to attack rolls.
  • Smoke Screen: Anything dropped on the ground is obscured by the smoke and ash; it requires a DC 13 Perception check. Any pits, trip wires, or other ground-based traps increase their DC to spot them by +2.
  • Ashen Disguise: All creatures exposed to the eruption for 20 minutes or more are so covered by ash that anyone trying to recognize them suffers disadvantage to their DC; likewise, any creatures wishing to use the ash as a Disguise gain advantage. Creatures covered by ash must make a successful DC 15 Constitution check or suffer 1 level of exhaustion from breathing ash.
  • Duration: 1 day to 50 years, with an average eruption time of 7 weeks. Not every eruption will be major and require this template, and not every eruption has lava; some shoot ash and/or rocks.

Wildfire

Nonmagical terrain, fire, ground-based

This is an out of control forest or brush fire.

  • Area of Effect: A forest or brush land and any neighboring land within 1d6 x100 miles.
  • Recognize Danger: Make a DC 12 Perception or Survival check to smell smoke and/or see the flames before they have spread. If you are successful, you have 1d3 x 10 minutes to escape before the area is engulfed and you start taking fire damage.
  • Difficult Terrain: You move at half-speed in this terrain as the smoke and fire obstruct you, as well as the undergrowth.
  • Fire Damage: This terrain deals 1 point of fire damage to all non-fire creatures for every round they remain exposed to it. For every 10 minutes, they must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion and take 1d6 fire damage from smoke inhalation. Creatures with resistance to fire are immune to these damage and exhaustion effects.
  • Fire Magic: All fire magic has its DC increased by +2 and deals an extra 1d6 fire damage whether the save is successful or not. In addition, the range of fire magic is tripled.
  • Cold and Water Magic: All cold and water magic has its DC decreased by -2. In addition, its range is halved.
  • Ranged Attack Penalty: Due to the shimmering air and smoke, as well as the flying cinders, plus the possible obstruction of any trees, all ranged weapon and spells by non-fire creatures suffer disadvantage to attack and spell rolls.
  • Smoke Screen: Anything dropped on the ground is swiftly obscured by the smoke; it requires a DC 12 Perception check. Any animal traps, pits, trip wires, or other ground-based traps impose disadvantage to spot them.
  • Duration: The average duration is 6 days, but this is variable, based on a combination of factors including weather, fuel, and efforts to control the fire. The longest wildfires can burn for 1d6 x 10 days and lay waste to up to 600 miles of terrain.

Obstacles or Challenges

Some of the following might resemble terrain or weather events but are different somehow.

Cloud Castle

Magical, terrain, air, force, lightning, thunder, sky

This is an area filled with one or more magical clouds that have substance enough to walk on and that move as directed by their owner. There may or may not be a literal castle or other buildings installed, or it could be a “castle” only in the metaphorical sense owing to its lofty status and relative security. It may be the work of a sky or storm god, a warlock patron, or the byproduct of a congregation of air elementals or cloud giants, or it could be the result of an altar, artifact, idol, or relic that has been installed and activated.

Radiates: Transmutation magic.

Area of Effect: Any, usually confined to one or more large interconnected clouds encompassing a total area of several hundred feet at the smallest all the way up to several miles. The clouds may be stacked to form layers or “levels.” If there are multiple clouds, they connect via bridges either made of the same cloud-like material or connected by stone or woodwork bridges. These bridges can be destroyed or cut loose as needed should the castle come under attack.

Expanded Area of Effect: If you wish to expand the area of effect beyond its original borders to threaten a wider area, simply expand it by 90 feet per minute (1 mile per hour). This terrain can only potentially expand a number of miles equal to the CR of the primary monster or villain, or up to 1 mile for an altar, artifact, idol, or relic.

Recognize Danger: Make a DC 15 Perception, Nature, or Survival check to recognize that the cloud is unusual in some way from the ground, or DC 13 from the sky beneath it. If you are above the cloud or level with it, the check to recognize it is magical is reduced to DC 10.

Dispel Magic: This terrain cannot be dispelled.

Difficult Terrain: Non-flying creatures (or those not native to living in magical clouds) move at half-speed in the actual cloud “ground” because the ground is spongy and dough–like. There is also no way for non-natives to tell which parts but may be solid and which are normal cloud. If you dare to move faster, you must succeed at a DC 15 Dexterity save or fall through a 1d4 x 5 foot gap that is not solid (basically, a pit trap).

These will be marked in some subtle way known only to natives of the cloud. Assuming the cloud is at its default height 1 mile (5,280 feet) above the earth, this is a lot of falling damage and a virtual death sentence without magic (fly, etc.).

Once you are on or in any stone or wood structure within the cloud castle, you may move normally within that terrain only.

To be considered native to the cloud castle, you must either be an air elemental or have lived in the cloud castle for a month or more.

Storm Damage: This terrain deals no damage unless the owner wills it, or it sails into contact with a storm, mountain, or other danger. However, as an action, the owner may command this terrain to deal its choice of 1d6 points of force (wind), lightning, or thunder damage (no save) to a number of creatures per round equal to its CR. It must choose the same damage type for all targets:

  • A creature struck by force damage (wind) must succeed at a DC 15 Dexterity save or be blown 1d4 x 5 feet in a direction of the owner’s choice (off the cloud if possible).
  • A creature struck by lightning damage must succeed at a DC 15 Dexterity save or be paralyzed for 1 round.
  • A creature struck by thunder damage must succeed at a DC 15 Constitution save or be deafened for 1 round and knocked prone.

The owner must be able to see and have line of sight to the creatures it attacks with this power, and they must be on the cloud or its structures, or within 2,000 feet of it if in the air, ground, etc.

  • Storm Magic: All air, cold, force, lightning, radiant, and thunder magic has its DC increased by +2 and deals an extra 1d6 damage of its type regardless of whether the save is successful or not. In addition, its range is tripled.
  • Conjuration and Teleportation Magic: The range, distance, and duration of movement and teleportation effects is doubled. This includes feather fall, fly, haste, jump, levitate, longstrider, misty step, slow, spider climb, teleport, etc.
  • Fire and Necromancy Magic: All such magic has its DC reduced by -2. Its range is halved.
  • Tracking: Tracking rolls on the clouds suffer disadvantage due to the weird, spongy texture. Air elementals, cloud giants, and creatures native to this terrain gain advantage instead. Tracking modifiers are negated inside stone or wood structures.
  • Tremorsense: Creatures with tremorsense suffer a -30 foot penalty while in the cloud parts of this terrain as they do not conduct vibrations well.
  • Cloud Cover: Any item dropped into the clouds is covered by them; it requires a successful DC 15 Perception check and 1d4 rounds to find and recover the item. If you fail your check by 5 or more, the item fell through a hole in the clouds and you are unlikely to ever see it again. Any pits, pressure plates, or ground-level traps covered by clouds impose disadvantage to spot them. (this is already factored into the chance to fall when moving fast over the difficult terrain).
  • Boss Fight: The primary monster or villain in this terrain (always the cloud castle’s owner) gains storm aura. Non-allies within 30 feet of it take 1 point of thunder damage per round. This damage is in addition to any similar abilities, traits, or powers the monster or villain has. Valid targets within 5 feet of the storm aura take 1 point of lightning damage and 1 point of thunder damage per round instead.
  • Terrain Anchor: If an altar, artifact, idol, or relic is causing the terrain, it has AC 10 and 120 hit points. It is immune to acid, cold, necrotic, poison, and psychic damage, and has resistance to all other damage types. It deals 4d4 lightning damage per round to anyone not attuned to it. Any creature killed by it are disintegrated and their soul used to power the cloud castle.
  • Duration: The terrain ends 1d12 hours after the primary monster or villain is driven out or destroyed, and/or the cause for the terrain is removed or destroyed (such as an idol or relic). If the primary monster or villain and/or cause for the terrain returns to the area, all terrain effects resume as before. However, the area of effect is reduced to half its original radius, centered on the primary monster, villain or cause. The area of effect increases by 10% per hour until it occupies its original radius.
  • See: This is a “kingdom in the clouds.”
  • Hear: The wind above, the birds below.
  • Sense (Physical): The clouds consist of a strange, spongy material that is misty and dough-like in consistency. It seems stable enough to support your weight… for now.
  • Sense (Mental): This area is unnatural yet beautiful… It would make a great base!

Fire or Burning Building

Nonmagical terrain, fire, ground-based

This is any wooden building that has caught fire; the longer you stay in it, the deadlier it becomes.

  • Area of Effect: The building, and possibly any neighboring buildings in a city, town, or village. There is a cumulative 25% chance per hour it burns to set 1d4 trees and/or wooden buildings within 120 feet of it on fire. If any wood targets are closer, the chance the fire also sets them ablaze increases to 33% per hour.
  • Recognize Danger: Make a DC 12 Perception or Survival check to smell smoke and/or see the flames before they have spread. If you are successful, you have 1d4+1 minutes to escape before the building is engulfed and you start taking fire damage.
  • Difficult Terrain: You move at half-speed in this terrain as the smoke and fire obstruct you.
  • Fire Damage (First 10 minutes): This terrain deals 1 point of fire damage to all non-fire creatures for every minute they remain exposed to it. After 5 minutes, you must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion and take 1d4 fire damage from smoke inhalation. Creatures with resistance to fire are immune to these ongoing effects.
  • Fire Damage (After 10 minutes): This terrain continues to deal 1 point of fire damage to all non-fire creatures for every round they remain exposed to it. For every 10 minutes, they must make a DC 17 Constitution saving throw or suffer 2 levels of exhaustion and take 2d4 fire damage from smoke inhalation.
  • Floor Collapse: Every round after the first 10 minutes in a multi-story building (including those with basements or cellars), there is a cumulative 10% chance a 10 x 10 foot section of the floor will collapse out from under you. To escape, you must be within 10 feet of a door, window, or exit (such as into the next room), and succeed at a DC 17 Dexterity saving throw. If you fail, you suffer 1d10 bludgeoning damage (from the fall and debris) and 2d6 fire damage and 2 levels of exhaustion. You are also knocked prone and stunned for 1d2 rounds.
  • Ceiling Collapse: Every round after the first 10 minutes, there is a cumulative 5% chance the ceiling will collapse. To escape in time, you must be within 10 feet of a door, window, or other exit, and succeed at a DC 17 Dexterity saving throw. If you fail, you suffer 4d6 bludgeoning damage and 4d6 fire damage and 2 levels of exhaustion. You are also knocked prone and restrained by fallen debris. It requires a DC 17 Strength save for someone else to free you or DC 20 to free yourself. Restrained or not, every round you remain in a burning building with a collapsed ceiling, you suffer 3d6 points of fire damage.

Tracking: Tracking rolls in a burning building suffer disadvantage in a burning building. Fire creatures gain advantage instead. If you introduce a new extreme template (like a burning building, earthquake, flood, etc.) into an encounter that’s already in progress, you may want to call for new Initiative rolls.

  • Fire Magic (First 10 minutes): All fire magic cast either inside or within a 60 foot radius of a burning building has its DC increased by +1 during the first 10 minutes and deals an extra 1d4 fire damage on a failed save.
  • Fire Magic (After 10 minutes): All fire magic cast either inside or within a 120 foot radius of a burning building has its DC increased by +2 after the first 10 minutes and deals an extra 1d6 fire damage regardless of whether the save is successful or not. In addition, the range of fire magic is doubled.
  • Cold and Water Magic (First 10 minutes): All such magic has its DC decreased by -1.
  • Cold and Water Magic (After 10 minutes): All such magic has its DC decreased by -2. In addition, its range is halved.
  • Ranged Attack Penalty: Due to the shimmering air, smoke, and flying cinders, ranged weapon and spells by non-fire creatures suffer a -2 penalty to attack rolls during the first 10 minutes and disadvantage afterward.
  • Smoke Screen: Anything dropped on the ground after the first 10 minutes is obscured by smoke; it requires a DC 10 Perception check to find. Any pits, trip wires, or other traps increase their DC to spot by +2 in the first 10 minutes, and by +4 after that.
  • Duration: 1d4+1 hours. The debris becomes difficult terrain that reduces movement to onethird speed until cleared. It remains hot for 1d4+8 hours after the main fire goes out and continues to deal 1 point of fire damage per round to any creatures that enter it.

Rotting Monster Carcass

Nonmagical terrain, air, necrotic, poison, ground-based

This is the corpse of any Huge or Gigantic monster left to rot. It has split open and is buzzing with flies and the stench of burst organs.

Area of Effect: 60 foot radius around corpse.

How to Remove It: Burn or bury the body.

Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the transition from normal to difficult terrain. If you succeed, you may stop before entering the area.

Difficult Terrain: You move at half-speed in a 60 foot area around the rotting carcass due to all the gore. Creatures moving in this terrain must make a DC 10 Dexterity save or slip in the foul rot and be knocked prone. Creatures who take damage from any source in this terrain must make a Dexterity save with a DC equal to 8 + the damage dealt or slip in a puddle of putrid gore and be knocked prone.

Poison Damage: The carcass is surrounded by a 60 foot poison stench. On every round you end your turn in this terrain, you must make a DC 13 Constitution save or be poisoned. You may make a new save each round until you succeed, or you can choose to spend an action vomiting. If you do, you end the condition but lose your reaction that turn. You may be poisoned by this terrain an unlimited number of times. Aberrations, celestials, elementals, fey, fiends, oozes, plants, undead, and creatures with resistance to poison are immune to these effects.

Air, Necromancy, and Poison Magic: All such magic has its DC increased by +1 and deals an extra 1d4 poison damage on a failed save regardless of whether it normally deals poison damage. In addition, its range is doubled.

Tracking and Stealth: Tracking rolls are made as normal, but Stealth rolls in this terrain suffer a -2 penalty due to all the squelching gore.

Duration: 1d4 weeks, or until removed.

Tornado

Nonmagical, air, force, weather-based

This is a funnel-shaped column of wind and debris that leaves a trail of destruction in its wake. It is also known as a cyclone, twister, or whirlwind.

  • Area of Effect: A 500 foot wide conical cylinder, 120 feet tall, that travels 1d4+1 miles at speeds of 10-20 miles per hour. Larger, faster ones exist that are up to 2 miles wide and travel 220 miles.
  • Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the impending danger. If successful, you have 1d10 minutes to find shelter before the tornado hits.
  • Difficult Terrain: You move at half-speed when the tornado is within 2,000 feet, and at one-third speed when it comes within 1,000 feet.
  • Storm Fatigue: For every round you remain exposed to the tornado, you must make a DC 15 Strength save or suffer 1 level of exhaustion due to fighting the wind and being pummeled by debris. Air elementals, non-living creatures, and those with resistance or immunity to force damage are immune to these ongoing effects.
  • High Wind Warning: For every round you spend exposed to this tornado, you suffer 1 point of bludgeoning damage (no save) as tiny debris slams into you and grit gets into your eyes/lungs. In addition, make a DC 13 Dexterity saving throw. If you fail, the tornado picks up a random object within 60 feet of you that is not being worn or carried; it hurls it into you for 2d6+2 bludgeoning damage. If you fail your roll by 5 or more, the object also strikes an adjacent creature within 10 feet of you. They may make a DC 15 Dexterity save for half damage.
  • Height of Tornado: If any 2nd level or higher air or force magic (gust of wind, spiritual weapon, wind wall, etc.) is used within 1,000 feet of a tornado, all creatures within range other than the caster who triggered this must succeed at a DC 15 Strength or Dexterity save or be hit by a wind wall spell for 1 minute (no concentration is required to maintain, as the storm is casting it). The caster has no control over who the wind hits.
  • Tornado Strike: When the tornado comes within 2,000 feet, you have 2 rounds to escape or find shelter. If you fail to get out of its path, make a DC 17 Strength or Dexterity save. If you succeed, you find something or someone to hold onto. You still take 1d10 force damage (no save) from the wind every round until you are pulled (or pull yourself) to safety. Each round, make a DC 15 Strength or Dexterity save. If you succeed, you pull yourself to the nearest safety. If you fail your save or are reduced to 0 hit points while exposed to the tornado, you lose your grip on whatever (or whoever) you are holding onto. You are violently ripped away and carried off by the tornado for 1d2 miles. You suffer 5d6 points of force and 5d6 points of bludgeoning damage, are knocked prone, and (assuming you survived) are incapacitated for 6 hours minus a number of hours equal to your Constitution modifier if it is positive (or plus if it is negative). The tornado deals 25 points of force and 25 points of bludgeoning damage per round to any objects in its path. Anything that cannot withstand the damage is destroyed and carried off. Anything smaller than a wooden cabin is automatically destroyed and/or carried off for 1d2 miles before smashing down again.
  • The Eye of the Storm: After 1d4+1 rounds, the center of the storm passes over you. This prevents any further damage or need for saves as long as it lasts. This gives any creatures who failed to find shelter a chance to do so, or the opportunity to find a new shelter if theirs was destroyed. After 1d4+1 rounds in the center of the storm, the area is hit by the second half of the tornado strike. Once the second half finishes passing over, all those previously within it are safe.
  • Storm Magic: All air and force magic within 2,000 feet has its DC increased by +2 and deals an extra 2d6 damage of its type regardless of whether the saving throw is successful or not.
  • All Other Magic: All acid, cold, fire, lightning, necrotic, radiant, thunder, and water magic within 2,000 feet have their DC reduced by -2, and any damage dealt is reduced by 2d6 on a successful save. This is because the tornado siphons off some and the winds rip away the rest.
  • Ranged Attack Penalty: If the tornado is within 2,000 feet, all living or non-air/storm creatures suffer a -10 penalty to ranged weapon and spell attack rolls. If the tornado is within 1,000 feet, you can only hit on a critical hit.
  • Dying of the Light: All nonmagical fires have their bright and dim light reduced by half when the tornado is within 2,000 feet and are extinguished when it comes within 1,000 feet.
  • Stealth: Stealth rolls made during a tornado are made with advantage when the storm is within 1,000 feet.
  • Duration: 2d4 hours. Roads will be impassable for 1d2 weeks afterward due to all the debris, then difficult terrain for the next 1d4+1 weeks.
  • Limit: 1d4 tornadoes can exist at the same time, but only one can occupy an area at a time. The same area can be hit by up to 2, but 1d4 hours apart.

Tracking: Tracking in a tornado is impossible. Reliable visibility and hearing is limited to 10 feet, and words are snatched by wind unless shouted.

Air- and storm-based creatures are immune to these penalties.

Combat

Non-air/storm creatures suffer disadvantage to Initiative within 1,000 feet of a tornado.

Windstorm

Nonmagical, air, force, weather-based

The sky turns gray and high winds howl in. This is a more or less “dry” storm with little to no rain; it has low winds in summer and high winds in spring or fall. You may stack a lightning and/or thunderstorm on top of this template.

  • Area of Effect: 1,200 (4d6 x 100) miles.
  • Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the impending storm. If successful, you have 1d3 x10 minutes to find shelter before the storm hits.
  • Difficult Terrain: You move at half-speed in this storm.
  • Storm Fatigue: For every hour you remain exposed to this storm, you must make a DC 13 Wisdom saving throw or suffer 1 level of exhaustion due to anxiety. Air elementals, nonliving creatures, and those with resistance or immunity to force damage are immune to these ongoing exhaustion effects.
  • High Wind Warning: For every 10 minutes you spend exposed to this storm make a DC 10 Dexterity saving throw. If you fail, the wind knocks debris into you that deals 1d4 bludgeoning damage.
  • Height of Wind: If any 2nd level or higher air or force magic (gust of wind, spiritual weapon, wind wall, etc.) is used within this storm, all creatures within 240 feet other than the caster who triggered this must succeed at a DC 13 Dexterity save or be hit by a gust of wind spell for 1 minute (no concentration required to maintain, as the storm is casting it). The caster has no control over who the wind hits.
  • Storm Magic: All air and force magic has its DC increased by +1 and deals an extra 1d4 damage of its type regardless of whether the saving throw is successful or not.
  • Cold, Fire, and Water Magic: All cold, fire, and water magic within the storm has its DC reduced by -1, and any damage dealt is reduced by 1d4 on a successful save. This is because the storm siphons off part of these magics to feed itself.
  • Ranged Attack Penalty: If the storm has high winds (regardless of rain), all living or non-air/ storm creatures suffer disadvantage to ranged weapon and spell attacks. If the storm has low winds and/or light rain, the penalty is only -2.
  • Dying of the Light: All nonmagical fires have their bright and dim light reduced by half.
  • Stealth: Stealth rolls made during this storm are made with a +2 bonus.
  • Duration: 2d4 hours. Forest roads will be impassable due to debris for 1d4 days afterward, and difficult terrain for the next 1d4 days.

Tracking: Tracking in a windstorm suffers disadvantage.

Reliable hearing is limited to 30 feet, and words are snatched away by high winds unless shouted.

Air- and storm-based creatures are immune to these penalties. Nonliving creatures (constructs, undead) reduce the penalty to -2.

Cold as Death

Magical, weather, cold, ground-based

This area is permeated by supernatural, bone-chilling cold. It may be the work of a god of winter, or the byproduct of a congregation of cold creatures such as frost giants, ice devils, or undead, or it could be the result of an altar, artifact, idol, or relic that has been activated and installed.

  • Radiates: Evocation (cold) and/or necromancy (if undead are present).
  • Area of Effect: Any, usually confined to a cave complex, crypt, dungeon, shrine, or tomb containing cold and/or undead creatures.
  • Expanded Area of Effect: If you wish to expand the area of effect beyond its original borders to threaten a wider area, simply expand it by 90 feet per minute (1 mile per hour). This terrain can only potentially expand a number of miles equal to the CR of the primary monster or villain, or up to 1 mile for an idol or relic.
  • Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the transition from normal to difficult terrain (or Arcana or Religion if undead are present). If you succeed, you may stop before entering.
  • Dispel Magic: Refer to the Casting Dispel Magic Against Magical Terrain rules.
  • Difficult Terrain: You move at half-speed in this terrain as its numbing cold slows you.
  • Cold Damage: This terrain deals 1 point of cold damage to all living or non-cold creatures for every minute they remain inside. For every 10 minutes, they must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion and take 1d6 cold damage from frostbite. Creatures with resistance to cold are immune to these ongoing damage and exhaustion effects.
  • Cold and Water Magic: All such magic has its DC increased by +2 and deals an extra 1d6 damage regardless of whether the save is successful or not. In addition, its range is doubled.
  • Fire Magic: All fire magic has its DC reduced by -2. In addition, its range is halved.
  • Ranged Attack Penalty: Due to the piercing blue-white “snow blind” terrain glow, all living or non-cold creatures suffer a -2 penalty to ranged weapon and spell attack rolls.
  • Dying of the Light: All nonmagical fires have their bright and dim light reduced by half.
  • Tracking: Tracking rolls suffer disadvantage.
  • Freezing Fog: Anything dropped on the ground is obscured by the low-lying fog and requires a DC 13 Perception check to find. Likewise, any pits, pressure plates, trip wires, or ground-level traps increase the DC to spot them by +2.
  • Boss Fight: When the party confronts the primary monster or villain in this terrain, its unnatural cold intensifies. Living or non-cold creatures within 30 feet of the primary monster or villain take 1 point of cold damage per round instead of every minute. This damage is in addition to any similar abilities, traits, or powers the monster or villain has. Living or non-cold creatures within 5 feet of it take 2 points of cold damage per round instead. Creatures with resistance to cold take no damage unless they come within 5 feet of it; at that point, they take 1 point of cold damage for each round they remain adjacent.
  • Terrain Anchor: If an altar, artifact, idol, or relic is causing the terrain, it has AC 10 and 120 hit points. It is immune to cold, necrotic, poison, and psychic damage, and has resistance to all other damage types. It deals 4d4 cold damage per round to any non-cold or non-undead creature touching it. Any creature killed by it turns to ice as if petrified. Such ice statues have AC 10 and 10 HP. They are immune to cold, necrotic, piercing, poison, psychic, and slashing damage but vulnerable to acid, bludgeoning, fire, lightning, and thunder damage.
  • Duration: The terrain ends 1d12 hours after the primary monster or villain is driven out or destroyed, and/or the cause for the terrain is removed or destroyed (such as an idol or relic). If the primary monster or villain and/or cause for the terrain returns to the area, all terrain effects resume as before. However, the area of effect is reduced to half its original radius, centered on the primary monster, villain or cause. The area of effect increases by 10% per hour until it occupies its original radius.

Storm (Blizzard)

Nonmagical terrain, air, cold, weather-based

A raging blizzard with 35-99 mile per hour winds piles up 1d4+2 feet of snow per day.

  • Area of Effect: 1,800 (6d6 x 100) miles.
  • Recognize Danger: Make a DC 15 Perception, Nature, or Survival check to recognize the impending transition from a simple snowstorm to a blizzard. If you are successful, you have 1d4 x 10 minutes to find shelter before the blizzard hits and you start taking damage.
  • Difficult Terrain: You move at one-third-speed in this terrain as its epic cold slows you.
  • Cold Damage: This terrain deals 1 point of cold damage to all living or non-cold creatures for every minute they remain exposed to it. For every 10 minutes, they must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion and take 1d6 cold damage from frostbite. Creatures with resistance to cold are immune to these damage and exhaustion effects.
  • Air, Cold, and Water Magic: All such magic has its DC increased by +2 and deals an extra 1d6 damage regardless of whether the save is successful or not. Its range is tripled.
  • Fire Magic: All fire magic within the blizzard has its DC reduced by -2. Its range is halved.
  • Ranged Attack Penalty: Due to the blinding snow and high wind, all creatures suffer a disadvantage to ranged weapon and spell attack rolls and ranges are halved.
  • Dying of the Light: All nonmagical fires have their bright and dim light reduced by half.
  • Stealth: Stealth rolls are made with advantage.
  • Snow Drift: Anything dropped on the ground is obscured by the snow and requires a DC 15 Perception check to find. Likewise, any pits, pressure plates, trip wires, or ground-level traps require a DC 20 Perception check to spot. However, there is a 50% chance the trap does not activate due to all the snow on top of it.
  • Duration: 3d8 hours minimum; if you roll 16+, it lasts up to a week (1d6+1 days). Assume roads become barely passable in 1d4+4 days in early or late winter, and 3d4+2 days in midwinter. Barely passable roads are difficult terrain that allow movement by creatures or vehicles at halfspeed until the snow melts (excluding sleds).

Tracking: Tracking in a blizzard suffers disadvantage. Any tracks are filled in within 1d4+1 minutes by snow, and scents are dispersed by the wind almost instantly. Visibility and hearing is limited to 30 feet at best, and words are snatched away by the wind unless shouted.

Cold creatures and undead only suffer a -2 penalty to track in a blizzard (and their visibility and hearing extends out to 60 feet instead).

Storm (Thunder Snow)

Nonmagical, air, cold, lightning, thunder, weather

This is a rare variety of winter storm that dumps 1d4+2 inches of wet snow (sleet) instead of rain. All other stats remain the same as winter storm, except the aftermath and cleanup will be worse. Assume roads will become barely passable in 1d3+2 days in early or late winter, and 1d4+3 days in midwinter. Barely passable roads allow movement by creatures or vehicles at half-speed until the debris is cleared and the roads dry up.

Storm (Hail)

Nonmagical terrain, cold, thunder, weather-based

A thunderstorm rains hard ice with concussive force that damages creatures, objects, and crops.

  • Area of Effect: 50 (10d10) miles.
  • Recognize Danger: Make a DC 13 Perception, Nature, or Survival check to recognize the impending transition from a few hailstones to a full-on storm. If you are successful, you have 1d4+1 minutes to find shelter before the hailstorm hits.
  • Difficult Terrain: You move at half-speed as the hail pummels you and gets underfoot.
  • Cold Damage: This terrain deals 1d4 points of bludgeoning damage to everything for every 5 minutes you remain exposed to it. For every 10 minutes, you must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion and take 1d2 points of cold damage in addition. Creatures with resistance to cold are immune to these ongoing damage and exhaustion effects.
  • Cold, Thunder, and Water Magic: All such magic has its DC increased by +1 and deals an extra 1d4 damage of its type on an unsuccessful saving throw. Its range doubles.
  • Fire Magic: Fire magic within the hailstorm has its DC reduced by -1.
  • Ranged Attack Penalty: Due to the heavy hail, all creatures suffer a -2 penalty to ranged weapon and spell attack rolls.
  • Duration: 2d6+3 minutes.

Storm (Snow)

Nonmagical terrain, air, cold, weather-based

A wild flurry of white swiftly blankets the area.

  • Area of Effect: 1,200 (4d6 x 100) miles.
  • Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the impending transition from a few flakes to full-on storm. If you are successful, you have 1d3 x10 minutes to find shelter before the storm hits.
  • Difficult Terrain: You move at half-speed in this terrain as the cold and snow slows you. Once the snow’s depth reaches 12 inches or more, you move at one-third speed until it gets lower.
  • Cold Damage: This terrain deals 1 point of cold damage to all living or non-cold creatures for every hour they remain exposed to it. In addition, every hour, they must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion and take 1d3 cold damage from frostbite. Creatures with resistance to cold are immune to these damage and exhaustion effects.
  • Air, Cold, and Water Magic: All such magic has its DC increased by +1 and deals an extra 1d4 damage on an unsuccessful saving throw.
  • Fire Magic: All fire magic within the snowstorm has its DC reduced by -1.
  • Ranged Attack Penalty: Due to heavy snow, all creatures suffer a -2 penalty to ranged weapon and spell attack rolls.
  • Snow Drift: Anything dropped on the ground is obscured by the swiftly falling snow and requires a DC 13 Perception check to find. Likewise, any pits, pressure plates, trip wires, or ground-level traps increase the DC to spot them by +2. However, there is a 25% chance the trap does not activate due to the snow on top of it.
  • Duration: Snow falls off and on for 1d3 hours at a time, and this occurs every 1d6 hours. The cycle repeats every day for 1d3 days. Assume a depth of 1d2 inches for every hour it snows.How long it takes for the snow to melt will depend on location, temperature, time of year, etc. Assume a default melt time of 1d4+1 days in early or late winter, and 2d4+2 days in midwinter.Assume roads will become barely passable in 1d2 days in early or late winter, and in 1d4+1 days in midwinter. Barely passable roads allow movement by creatures or vehicles at half speed until the snow melts (excluding sleds).

Storm (Winter)

Nonmagical, air, cold, lightning, thunder, weather

Bitter cold, heavy rain, and high winds howl in, accompanied by lightning and peals of thunder. Older adventurers claim thunder in winter is a “sure sign” a snowstorm will arrive in 1d6+4 days.

  • Area of Effect: 1,200 (4d6 x 100) miles.
  • Recognize Danger: Make a DC 10 Perception, Nature, or Survival check to recognize the impending transition from a few drops of rain to full-on storm. If successful, you have 1d3 x10 minutes to find shelter before the storm hits.
  • Difficult Terrain: You move at half-speed as the extreme weather and wind slows you.
  • Cold Damage: This terrain deals 1 point of cold damage to all living or non-cold creatures for every hour they remain exposed to it. In addition, every hour, they must make a DC 15 Constitution saving throw or suffer 1 level of exhaustion and take 1d2 cold damage. Undead and creatures with resistance to cold are immune to these ongoing damage and exhaustion effects.
  • Winter’s Warning: For every 10 minutes you spend exposed to this storm, make a DC 10 Dexterity saving throw. If you fail, the wind knocks debris into you that deals 1d4 bludgeoning damage. For every hour you spend exposed to this storm, you must make a DC 10 Dexterity save. If wearing metal armor, the DC increases to 13. If you fail, you are hit by a lightning bolt (as if by the spell) that deals 8d6 lightning damage and knocks you prone.
  • Winter Storm Magic: All air, cold, lightning, thunder, and water magic has its DC increased by +2 and deals an extra 1d4 damage of its type on an unsuccessful saving throw.
  • Fire Magic: All fire magic within the storm has its DC reduced by -1.
  • Ranged Attack Penalty: Due to the rain and wind, all creatures suffer disadvantage to ranged weapon and spell attacks.
  • Duration: Rain falls nonstop in sheets for 3d4 hours, accompanied by 1d4+2 x10 mile per hour winds, thunder, and lightning. It dumps 1d4+4 inches of rain and strews debris everywhere.Assume roads will become barely passable in 1d2+1 days in early or late winter, and 1d4+1 days in midwinter. Barely passable roads allow movement by creatures or vehicles at half-speed until the debris is cleared and the roads dry up.

Tracking: Tracking in a snowstorm suffers disadvantage. Tracks are filled in by snow within 1d4 hours, and scents dispersed by wind. In addition, reliable visibility and hearing is limited to 90 feet at best.

Cold creatures and undead only suffer half penalties to track in a snow storm (-2 to track, and 120 feet for visibility/hearing).

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