Trap Design

Contents

Traps

Hazards

Haunts

Traps have had a place in both adventures and fantasy fiction for years, and have become a staple of the genres. Unfortunately, they also don’t seem to get much attention during the adventures that you and your friends are engaging in around the table, and often they take the backseat to the monsters that the heroes encounter. While that is unlikely to change, we would like for these timeless classics to have more of a role.

Part of the problem with them is a matter of presentation. The way they’re usually presented makes it difficult for a Game Master to implement them quickly at the table. As such we’ve changed the way that they’re presented within this book to make it easier for you to quickly use them at your table.

As such, you’ll find some of the traps that you already know have been recreated in this book, to show how this would work. At the same time there are a number of new traps for you to bedevil and threaten the heroes with.

In many ways, the same issue applies to hazards. There are so many ways that heroes could encounter various non-monster (or trap) threats, in the form of the environment, haunts, and other challenges that needed to be explored.

Traps and hazards were very abstract in how they were run, and how they were handled in terms of danger, save DC and attack bonuses. So we have codified this into a simple system. We also felt that it was necessary that heroes would receive experience points for defeating or even surviving these hazards. So these are as follows.

It is worth noting that traps and hazard Challenge Ratings only go to 20. This is because at that point most traps and hazards become trivial for the heroes to overcome, and should be tailored to the party instead.

  • Challenge Rating (CR) is the level where a group of 4 players can expect to overcome the trap with a bit of effort. If the group is smaller than 4, use a trap with a lower CR. If there are more heroes in the group than 4, use a trap with a higher CR.
  • XP is how many experience points that the heroes receive for overcoming the trap or hazard.
  • Max. Damage is the maximum amount of damage that the trap should do in any single given attack on a single hero. Traps with larger areas of effect can easily do more damage, or have secondary effects.
  • Max. Save DC is the maximum saving throw difficulty class that a trap should have. This might be higher or lower depending on the damage it deals (lower damage with higher Save DC is fine for example).
  • Max. Attack Bonus is the maximum attack bonus that the trap should have at that Challenge Rating, though like the Max Save DC it can go up or down, depending on the damage it can deal.

For both Traps and Hazards, you’ll also find that each type has a specific template that it sticks to, to make it easier for you, as the GM, to use it. These will be explained in each section separately.

Challenge Rating XP Max. Damage Max. Save DC Max. Attack Bonus
1 40 10 11 3
2 90 20 11 3
3 140 30 12 4
4 220 40 12 4
5 360 50 13 5
6 460 60 13 5
7 580 70 14 6
8 780 80 14 6
9 1,000 90 15 7
10 1,180 100 15 7
11 1,440 110 16 8
12 1,680 120 16 8
13 2,000 140 17 9
14 2,300 150 17 9
15 2,600 170 18 10
16 3,000 180 18 10
17 3,600 200 19 11
18 4,000 215 19 11
19 4,400 230 20 12
20 5,000 240 20 12

Traps

Traps are a commonplace occurrence in many dungeons and even in the home of many rich merchants. These are effects, usually mechanical or magical in nature, that are placed purposefully to alert the inhabitants, slow down the intruders, incapacitate or restrain them, or finally, kill the unwary and unwelcome. Most traps are placed so that they escape notice and are triggered accidentally, but some devious traps are created to lure people to trigger them such as by interacting with them, usually by touching them.

Traps are typically separated into two categories: Simple and complex. Simple traps have a single mechanism that they work on, such as a bear trap’s “you step in it, and the jaws close on your leg”. Complex traps are often multistage, performing several actions in a row (or the same ones repeatedly) in order to destroy an intruder. As an example, the Wheel of Death first closes the door, then triggers the blades, and spins them up as the stone in the middle pulses throwing the intruders towards the blades. Complex traps are much more taxing for a GM to run in a game though, and as such, the vast majority of traps in this book are simple ones.

Furthermore, traps are divided into three types, mechanical, magical, and combined. Mechanical traps are purely mechanical in nature (such as a bear trap), magical traps are spells or magical effects that have been placed on an area such as the sphere of annihilation, and finally, there are the rare traps that combine the two, such as the wheel of death.

There are 2 templates for traps within this book, one for simple traps and one for complex traps, and this is how they break down.

Simple Trap Name | CR – Challenge Rating

Description of trap type: simple and magical, mechanical or combination

Appearance This describes what the trap looks like, typically from the viewpoint of the heroes, though not always.

Trigger This is how the trap is activated.

Detection The DC for the Wisdom (Perception) check to find the trap. In some cases, only parts of the trap are revealed. Please also remember that a character who is deliberately searching could swap Intelligence (Investigation) for Wisdom (Perception), if the GM allows it for that specific situation.

Disarming and Destroying These are the steps that allow a hero to destroy a trap.

Damage and Effects What the trap does in mechanical terms when triggered.

Complex Trap Name | CR – Challenge Rating

Description of trap type: complex and magical, mechanical or combination

Appearance This describes what the trap looks like, typically from the viewpoint of the heroes, though not always.

Trigger This is how the trap is activated.

Detection The DC for the Wisdom (Perception) check to find the trap. In some cases, only parts of the trap are revealed. Please also remember that a character who is deliberately searching could swap Intelligence (Investigation) for Wisdom (Perception), if the GM allows it for that specific situation.

Initiative Because of its complexity and the multiple elements of a trap, a complex trap acts as a creature with initiative. Some elements might act with different initiative counts, depending on whether they are active or dynamic (constant elements do not have an initiative, as they are constant).

Active Elements These are the active elements of the trap. These are things like blades that slide out of nowhere or a door that crushes down on any creature nearby.

Dynamic Elements Dynamic elements come from the way that the trap functions. Usually, these changes involve dramatic elements that happen at the end of the trap’s turns (or on the initiative count of that element), or in response to the actions of the heroes. This could be the aforementioned blades speeding up or slowing down, or an effect of the trap that changes.

Constant Elements Even out of turn, a complex trap can still pose a threat. The constant elements are usually passive effects that require an attack roll from the trap, or a saving throw from any creatures within range. These effects usually take place at the end of the creature’s turn.

Disarming and Destroying These are the steps that allow a hero to destroy a trap.

Example Traps

Dart Trap CR 1 — 2

Simple mechanical trap

Appearance Several concealed holes adorn both sides of a room or corridor, with so many openings spread across that it’s impossible to pass without being in front of at least a few of them.

Trigger A creature or object weighing more than 20 pounds steps or lands on the pressure plate that activates the trap.

Detection A successful DC 15 Wisdom (Perception) check reveals the holes in the wall and the presence of a trap, but a separate DC 15 Intelligence (Investigation) check is required to reveal where the pressure plate is.

Disarming or Destroying A successful DC 15 Dexterity check using thieves’ tools disables the lever (if the person attempting it can reach the lever) or the pressure plate.

Damage and Effects When triggered, the Dart Trap fires 4 darts.

Each dart makes a ranged attack with a +8 bonus. These darts target a random creature within 10 feet of the pressure plate. Each creature that is hit takes 2 (1d4) piercing damage.

Some of these traps are poisoned (adding 1 to the CR), in which case any creature hit must succeed on a DC 15 Constitution saving throw, taking 11 (2d10) poison damage on a failed save, or half as much damage on a successful one.

Divide and Conquer CR 1

Simple mechanical trap

Appearance An empty room with a 6-inch deep and 12 inches wide trench dividing the room into two equal sizes, with two doors leading out of the room, diametrically across from each other.

Trigger A minimum of two creatures enter the room and are separated on each side of the room.

Detection A successful DC 11 Wisdom (Perception) check reveals the trap.

Disarming or Destroying A successful DC 11 Dexterity check using thieves’ tools disables it by jamming the wall mechanics. The trap cannot be destroyed, but the wall that slides down can. It has an AC of 17 and 50 hit points. The doors leading out on either side have an AC of 15 and 30 hit points, as they are steel-reinforced.

Damage and Effects When triggered, both doors close, and a wall slowly descends from the roof, separating the room into two. It does this slowly enough that anyone on one side can make it to another without issue.

On the wall is a lock. The lock unlocks the door on the other side of the room, and can be picked with a successful DC 12 Dexterity check using thieves’ tools. There is no other way of opening the doors on either side (i.e. to open the one on the left side, you must pick the lock on the right side, and vice versa). The doors can be opened from the outside of the room as normal, though they are locked. They can still be picked as normal.

The trap resets when the doors are opened at the same time.

GM’s Note: This trap is deliberately designed to slow down or restrain the heroes from going anywhere. Not all trap-makers want to kill people.

Elevator Room CR 1

Simple mechanical trap

Appearance An empty room with 4 doors, one on each wall.

Trigger A minimum of one creature enters the room and spends 1 round in the room.

Detection A successful DC 12 Wisdom (Perception) check reveals the trap.

Disarming or Destroying A successful DC 12 Dexterity check using thieves’ tools disables it by jamming the elevator mechanics. The doors can be destroyed. Each has an AC of 17 and 20 hit points. They can also be forced open with a DC 20 Strength (Athletics) check.

Damage and Effects When triggered, any open doors close 1round later, to trap as many people as possible.

Once the doors close, they lock and the room descends, one level (or 20 feet) per round. This continues until the Elevator Room reaches the bottom at which time the doors open.

GM’s Note: This trap is deliberately designed to bring creatures in over their heads and is only used in dungeons and other areas where there is a significant increase in danger the further one goes. As such, it is not unusual to find these in the lairs of liches and dragons, who often find that those caught in such a simple trap make for easy fodder.

Falling Net CR 1

Simple mechanical trap

Appearance A net is suspended from above, with a tripwire activating the trap, capturing those caught beneath it.

Trigger When a creature moves the tripwire the trap triggers.

Detection A successful DC 10 Wisdom (Perception) reveals the tripwire and the net.

Disarming or Destroying A successful DC 15 Dexterity check using thieves’ tools breaks the tripwire harmlessly.

Anyone with an edged weapon or tool can attempt the check, but they have disadvantage when doing so.

Failing the check triggers the trap.

Damage and Effects When the trap is triggered, the net releases, covering a 10-foot-by-10-foot area.

Those within that area are restrained and those that fail a DC 10 Strength saving throw are knocked prone.

A creature can free itself (or any creature in range) by using an action to make a DC 10 Strength (Athletics) check and succeeding.

The net has AC 10 and 20 hit points, and for each 5 slashing damage dealt, a 5-foot square section is destroyed, which frees any creatures trapped in that section.

GM’s Note: An alternate version of this has the net spread on the ground, and when triggered, pulls the creatures in the area into the air, suspending them from above, at least 20 feet up. This works similarly to the falling net, but any creatures who free themselves (or where the net is destroyed) fall to the ground taking 7 (2d6) bludgeoning damage (this increases the CR of the trap to 2).

Falling Wasp Nest CR 1

Simple mechanical trap

Appearance A small wire or string is stretched across the ground, set to trip anyone crossing it. Once tripped, a wasp nest falls from a perch above, pulled down by the string, breaking it open and unleashing the angry wasps.

Trigger A creature triggers the wire.

Detection A successful DC 12 Wisdom (Perception) check reveals the trap.

Disarming or Destroying A successful DC 10 Dexterity check using thieves’ tools disables it. The trap can be destroyed by dealing 1 point of damage to it. It has an AC of 12.

Damage and Effects The trap drops a wasp nest from at least 10 feet above, breaking it open upon impact with the ground. The wasps immediately stream out and sting anyone within a 10 foot radius.

Anyone within a 10 foot radius must make a DC 10 Dexterity saving throw. On a failed save, a creature takes 3 (1d6) piercing damage, or half as much on a successful one. The wasps remain in the area for 1 minute, attacking anyone who comes into the radius. After 1 minute they disperse automatically.

Ladder To Nowhere CR 1

Simple mechanical trap

Appearance A square trapdoor with 2-½-foot long sides in a scuffed wooden floor reveals a metal ladder that descends to an unlit room below. The ladder is bolted to the wall of the room below.

Trigger A lever disguised to look like a ladder rung is located 50 feet down the 70-foot long ladder.

When five pounds of pressure is applied to the rung, it triggers a mechanism hidden behind the wall that releases a block of stone concealed in the ceiling in the room above.

Detection If a creature examines the ceiling, a successful DC 15 Wisdom (Perception) check reveals the seams of a square outline with 3-foot long sides. If a creature examines the ladder as they descend it, a successful DC 15 Wisdom (Perception) check reveals the false ladder rung.

Disarming or Destroying A successful DC 5 Dexterity check allows a creature to avoid the ladder rung that triggers the trap. A successful DC 10 Dexterity check using thieves’ tools disarms the trap as the hero stabilizes the false rung.

Damage and Effects When the lever activates, a 3-foot long by 3-foot wide by 6 inches thick cut-out section of the stone ceiling in the top room is released and lands over the trapdoor sealing off the room’s only exit. The stone slab weighs 800 pounds, which can be pushed, dragged, or lifted as normal.

Pit Trap CR 1 — 5

Simple mechanical trap

GM’s Note: Pit Traps are generally put into three categories: Standard (CR 1), Hidden (CR 2), and Locking (CR 3). Any of these can have spikes and other nasty effects added to them (Adding 1 to the CR). Finally, a spiked pit can have an injury poison on the spikes (which adds a further 1 to the CR for a total of 2 for spikes and poison).

Appearance A hole in the ground hidden beneath a carpet, blanket, or similar material that hides the opening. The hole drops down at least 10 feet.

Trigger A creature steps on the covering material.

Detection Standard: A successful DC 10 Wisdom (Perception) check reveals the trap.

Hidden: A successful DC 15 Wisdom (Perception) check reveals the trap as the hero discerns the lack of traffic across that section of ground. For the hidden pit, it is always a trapdoor that covers the hole, making it blend almost seamlessly with the ground.

Locking: A locking pit is similar to a hidden pit for detection purposes.

Disarming or Destroying Standard: A standard pit trap cannot be disarmed, and destroying it is a simple matter of filling the hole with dirt or some other material.

Hidden: The trapdoor of a hidden pit can be disabled with a DC 11 Dexterity check using thieves’ tools to jam the trapdoor, preventing it from opening. The trapdoor can also be destroyed. The AC and hit points depend on its material, but in most dungeons, it is made of stone and has an AC of 17 and 20 hit points.

Locking: The trapdoor of a locking pit functions like the trapdoor of a hidden pit, but opening the lock requires a DC 15 Dexterity check using thieves’ tools if the trap has already been triggered (before this point, it can be disabled like a hidden pit). It has the same AC and hit points as a hidden pit, but the trapdoor can be pried open with a successful DC 20 Strength (Athletics) check.

Damage and Effects All pits deal damage to those who fall into them, depending on the depth. For every 10 feet deep that the pit is, it deals 3 (1d6) bludgeoning damage (Up to a maximum of 20d6). Most pits are between 10 and 20 feet deep.

Spiked pits have sharpened stakes at the bottom of the pit, often made from wooden stakes or iron spikes. These deal an additional 11 (2d10) piercing damage on top of the falling damage.

Finally, some of the spiked traps have poison smeared on them. This can be any poison of the creator’s choice, but the most typical one requires a DC 13 Constitution saving throw, taking 22 (4d10) poison damage on a failed save, or half as much damage on a successful one.

Ankle Chopper CR 2

Simple mechanical trap

Appearance A set of wooden stairs leads up to an open door.

Trigger When stepped on, the tread halfway up the staircase is a pressure plate that pulls the panel on the step’s riser down.

Detection If a creature examines the step, a successful DC 10 Wisdom (Perception) check reveals a different sound behind the trapped riser.

Disarming or Destroying A successful DC 5 Dexterity check allows a creature to skip the trapped step to avoid triggering the trap. A DC 10 Dexterity check using thieves’ tools will successfully support the pressure plate to keep it from depressing and prevent the trap from tripping.

Damage and Effects A handaxe springs out from under the stair and strikes the shin of the creature that stepped on the pressure plate dealing 1d6 + 1 point of slashing damage. Simultaneously, grease is released that flows down the stairs.

Each creature on the staircase must make a successful DC 11 Dexterity save or slip and tumble down to the base of the stairs taking the appropriate amount of damage for the distance fallen.

Bear Trap CR 2

Simple mechanical trap

Appearance A set of iron jaws, in the form of a bear trap, are set upon the ground and covered.

Trigger A creature steps on the bear trap.

Detection A successful DC 10 Wisdom (Perception) check reveals the trap.

Disarming or Destroying A successful DC 10 Dexterity check using thieves’ tools disables it. The trap can be destroyed by dealing 5 points of damage to it. It has an AC of 12.

Damage and Effects The trap makes an attack against the triggering creature. The attack has a +8 attack bonus and deals 5 (1d10) piercing damage on a hit. This attack can’t gain advantage or disadvantage. A creature hit by the trap has its speed reduced to 0. It can’t move until it breaks free of the trap, which requires a successful DC 15 Strength check by the creature or another creature adjacent to the trap.

Crushing Door CR 2

Simple mechanical trap

Appearance A closed wooden door.

Trigger Turning the door handle.

Detection A successful DC 10 Wisdom (Perception) check reveals deteriorated hinges and no airflow coming from under the crack of the door.

GM’s Note: There’s no airflow because it’s a false door. There is no room behind the door, only a wall.

Disarming or Destroying A successful DC 10 Dexterity check using thieves’ tools jambs the mechanism in the handle so it can’t release acid onto the hinges.

Damage and Effects Acid coats the hinges causing them to dissolve which releases the door that falls forward onto the creature that triggered the trap. The creature must make a DC 10 Dexterity saving throw. On a failed save, the creature takes 11 (2d10) bludgeoning damage and is pinned under the door, or half as much damage on a successful save. A creature is not pinned on a successful save. Every round a creature starts its turn pinned under the door, it takes 1d6 points of bludgeoning damage. A creature can use its action to push the door off a pinned creature with a successful DC 15 Strength (Athletics) check.

Seat of Entrapment CR 2

Simple mechanical trap

Appearance An ornate, stone throne sized for an adult humanoid with a coin-sized ruby embedded on each of its arms.

Trigger Sitting on the throne with at least 50 pounds of weight releases a concealed catch underneath the seat that is holding the stone arms in place.

Detection A successful DC 10 Wisdom (Perception) or Intelligence (Investigation) reveals the concealed catch under the seat and the sliver of a groove where the hinges are located at the spots where the arms and the back of the chair meet.

Disarming or Destroying A successful DC 10 Dexterity check using thieves’ tools to block the catch from releasing will prevent the trap from tripping. If the trap is tripped, a creature that is not pinned in the throne can make a successful DC 12 Strength (Athletics) check to manually reset the catch under the seat which will release the arms and reset them to their original open position.

A creature pinned in the chair can make a successful DC 12 Dexterity (Acrobatics) check to wriggle free from the arms. A creature larger than Medium makes the check at disadvantage.

Damage and Effects When the trap triggers, a creature sitting on the throne can make a DC 12 Dexterity saving throw to leave the throne before the released arms come together to entrap the creature on the throne. A creature sitting on the throne when the arms come together takes 11 (2d10) points of bludgeoning damage and gains the restrained condition.

Corpse Box CR 3

Simple combination trap

Appearance An ornate stone coffin decorated with images of people being trapped alive inside it.

Trigger A creature opens the trap.

Detection A successful DC 14 Wisdom (Perception) check reveals the trap. Detect magic reveals an aura of conjuration magic emanating from inside the coffin.

Disarming or Destroying The Corpse Box cannot be disabled through mechanical means, though it can be opened after it has triggered with a successful DC 14 Dexterity check using thieves’ tools. The trap can be destroyed by dealing 15 points of damage to it. It has an AC of 16. This destroys the lid, and if there is a trapped occupant, they can escape.

Damage and Effects As tentacles emerge, the trap makes an attack against the triggering creature. The attack has a +5 attack bonus and deals 5 (1d10) bludgeoning damage and the target is grappled (escape DC 17). Until this grapple ends, the creature is restrained.

The target is then dragged into the coffin which slams shut revealing that it is lined with spikes, which pierce the trapped occupant.

This automatically causes 10 (2d10) piercing damage on each round that the creature is trapped.

Once the occupant is dead, the trap opens and the corpse is expelled. This resets the trap.

Deterring Door CR 3

Simple magical trap

Appearance An immobile door with no obvious knob or lock has an intricate brass knocker on it in the form of a jester’s head.

Trigger A creature that uses the knocker triggers the trap.

Detection A successful DC 15 Wisdom (Perception) check or DC 15 Intelligence (Arcana) check reveals an arcane symbol on the underside of the door knocker incorporated into its elaborate design. Detect magic reveals abjuration and enchantment auras on the door.

Disarming or Destroying Dispel magic (DC 12) will dispel the enchantment magic and the arcane lock on the door.

Damage and Effects The arcane lock spell doesn’t deal damage to nearby creatures, but it does keep them from entering unless they employ a knock spell or physically destroy the door.

After a creature uses the door knocker, they hear the following words (in Common) in their mind: “Travel as far away from here as you possibly can.” If the creature doesn’t understand common or can’t be charmed, it is immune to the effects. Otherwise, it must make a DC 12 Wisdom saving throw. On a failed save, the creature must comply with the request to the best of its ability for the next hour.

Hall of Mirrors CR 3

Simple magical trap

Appearance A hallway (25-feet long & 5-feet wide) with an arch at both ends has several paintings, ornate mirrors, and clay busts lining the walls. A thin red carpet runs down the center of the hall. A carved lion’s head adorns the top of the first arch. When a creature approaches within 5-feet of the lion’s head, a magic mouth spell activates and the lion says, “speak the password or go no further”.

Trigger A creature passes under the exit arch without having said “the password” aloud.

Detection Detect magic on the second arch reveals an aura of evocation magic. A successful DC 15 Intelligence (Investigation) or Intelligence (Arcana) check reveals a glyph inscribed on the underside of the exit arch.

Disarming or Destroying Dispel magic (DC 12) dispels the glyph. A successful DC 15 Intelligence (Arcana) ability check also destroys the glyph as the hero disrupts the magic pattern of the glyph.

Detect magic reveals an aura of illusion magic centered on the sigil.

Damage and Effects As the glyph triggers, it releases a shatter spell.

All creatures within 10 feet of the exit arch must make a DC 12 Constitution saving throw.

A creature takes 13 (3d8) thunder damage on a failed save, or half as much on a successful save. Simultaneously, the mirrors shatter and send flying glass shards into the hallway.

All creatures within 10 feet of the exit arch must make a DC 15 Dexterity saving throw. A creature takes 13 (3d8) slashing and piercing damage on a failed save, or half as much on a successful save.

Lure of Greed CR 3

Simple mechanical trap

Appearance A backpack, sack, or chest that has been badly hidden.

Trigger A creature opens or moves the container.

Detection A successful DC 13 Wisdom (Perception) check reveals the trap.

Disarming or Destroying A successful DC 15 Dexterity check disables it. Failing the check triggers the trap. The trap cannot be destroyed without destroying the container.

Damage and Effects The trap unleashes a cloud of poison in a cone 10 feet long, centered on the container, in the direction of the creature opening it. All creatures within the cone must make a DC 12 Constitution saving throw. On a failed save, it takes 6 (1d12) poison damage and is poisoned for 24 hours. On a successful save, the creature takes half damage and isn’t poisoned.

The container may or may not be full at the GM’s discretion, but it is likely empty as it was badly hidden on purpose to tempt would-be thieves into disturbing it.

Needle Trap CR 3

Simple mechanical trap

Appearance A chest or door, or similar object that a creature would want to open.

Trigger The object is opened, triggering the trap.

Detection A successful DC 20 Intelligence (Investigation) check reveals the presence of the trap, as alterations are made to the locking mechanism of the object. Casual inspection, such as with a Wisdom (Perception) check, is not enough to reveal the presence of the trap.

Disarming or Destroying A successful DC 15 Dexterity check using thieves’ tools disarms the trap, allowing the object to be opened safely. Failure triggers the trap.

Damage and Effects When the trap is triggered a needle extends 3 inches straight out from the lock, damaging the creature manipulating the object. That creature takes 1 piercing damage and 11 (2d10) poison damage and must succeed on a DC 15 Constitution saving throw or be poisoned for 1 hour.

Punji Sticks CR 3

Simple mechanical trap

Appearance Several sharpened sticks, usually smeared with sewage or other diseased filth, strike from tension, impaling a victim.

Trigger When a creature moves the tripwire the trap triggers.

Detection A successful DC 15 Wisdom (Perception) check reveals the tripwire.

Disarming or Destroying A successful DC 15 Dexterity check using thieves’ tools cuts or disables the trip wire safely (the person making the check can reset the trap if they wish). Anyone with an edged weapon or tool can attempt the check, but they have disadvantage when doing so. Failing the check triggers the trap.

Damage and Effects When triggered, the punji sticks strike out, attacking the triggering creature. The sticks make a single melee attack with a +8 bonus.

The triggering creature takes 6 (3d4) piercing damage if they are hit.

They must also make a DC 10 Constitution saving throw or contract a nasty disease. If they fail the saving throw, they become poisoned until the disease is cured. For every 24 hours that elapse, the target must repeat the saving throw, reducing its hit point maximum by 2 (1d4) on a failure. The disease is cured on a success. The target dies if the disease reduces its hit point maximum to 0. This reduction to the target’s hit point maximum lasts until the disease is cured.

This trap must be manually reset.

Rope Bridge Trap CR 3

Simple mechanical trap

Appearance A rickety bridge crosses a large chasm.

Trigger When more than two Medium-sized creatures step on the bridge, it collapses, or it is activated by a creature cutting one of the ropes.

Detection A successful DC 12 Wisdom (Perception) reveals that the bridge is unstable and could collapse if too much weight is put on it.

Disarming or Destroying The trap cannot be disarmed. Destroying it is a simple matter of cutting the ropes, which have an AC of 5 and 2 hit points. This drops any creatures currently on the bridge into the chasm below.

Damage and Effects When activated, the triggering creatures are dropped to the chasm below unless they succeed on a DC 17 Dexterity saving throw.

Each creature takes falling damage from the drop (typically this drop is at least 50 feet, meaning they take 17 (5d6) bludgeoning damage). Some trapmakers fill the chasm below with spikes like a pit trap. These deal an additional 11 (2d10) piercing damage on top of the falling damage. (and increases the CR by 1) Finally, some of the spikes may have poison smeared on them. This can be any poison of the creator’s choice, but the most typical one requires a DC 13 Constitution saving throw, taking 22 (4d10) poison damage on a failed save, or half as much damage on a successful one. (which increases the CR by a further 2, to a total of 6).

Sewer Pit CR 3—4

Simple mechanical trap

Appearance A trap door drops the heroes into a pit. The door then closes and the pit trap fills with sewage.

Trigger A creature steps on the trap door.

Detection A successful DC 12 Wisdom (Perception) check reveals the trap.

Disarming or Destroying A successful DC 12 Dexterity check using thieves’ tools disables it by jamming the trap door closed. The trap door can be destroyed (AC 14 and 15 hit points), but this only leaves the pit open and creatures can still fall into it.

Damage and Effects Any creature that falls into the 30-foot deep pit takes 3d6 bludgeoning damage from the fall.

Immediately thereafter the cover closes, and the pit begins to fill with a mix of sewage and water.

After 2 rounds the pit is filled, and the creature must hold its breath or begin drowning.

They must also make a DC 10 Constitution saving throw or contract a nasty disease. If they fail the saving throw, they become poisoned until the disease is cured. Every 24 hours that elapse, the target must repeat the saving throw, reducing its hit point maximum by 2 (1d4) on a failure. The disease is cured on a success. The target dies if the disease reduces its hit point maximum to 0. This reduction to the target’s hit point maximum lasts until the disease is cured.

A successful DC 20 Strength (Athletics) check is necessary to pry the cover open. The cover can also be smashed open. A character in the pit can also attempt to disable the spring mechanism from the inside with a DC 15 Dexterity check using thieves’ tools, provided that the mechanism can be reached and the character can see. In some cases, a mechanism (usually hidden behind a secret door nearby) opens the pit.

GM’s Note: Some of these only fill with normal water, drowning the triggering creature. These are CR 3.

Smoke & Arrows CR 3

Simple mechanical trap

Appearance A 15-feet-by-15-feet torch-lit foyer has two wooden statues armed with light crossbows.

The statues stand on opposite walls 5 feet into the room.

Trigger A trip wire stretched between the two statues causes the crossbows to fire.

Additionally, a pressure plate is located directly in front of the exit door at the other end of the foyer.

Detection A DC 5 Wisdom (Perception) check reveals that the crossbows are functioning.

GM’s Note: This is the “red herring”. The heroes are supposed to discover this part of the trap, to lure them into missing the second one.

A successful DC 8 Wisdom (Perception) check reveals the trip wire.

A successful DC 15 Wisdom (Perception) check reveals all of the following: the pressure plate, the secret compartment on the wall behind the lit torch at the exit door, and a scorch mark on the wall near the torch.

Disarming or Destroying A successful DC 13 Dexterity check using thieves’ tools allows a creature to snip the trip wire without triggering the first part of the trap.

The crossbows can be removed and used as functioning weapons.

A successful DC 13 Dexterity check using thieves’ tools will prevent either the pressure plate or the secret compartment from functioning as the hero jams them in place.

Damage and Effects One crossbow bolt from each statue attacks the creature activating the trip wire. Each bolt makes a ranged attack with a +8 bonus, and deals 1d8 piercing damage.

As the pressure plate depresses, a secret compartment on the wall behind the lit torch slides open, and oil is sprayed onto the torches causing a burst of fire to flare up in a 5-foot radius. Creatures in the radius must make a DC 12 Dexterity saving throw. On a failed save, the creature takes 12 (2d10) fire damage, or half as much on a successful save.

Stairway to Pain CR 4

Simple mechanical trap

Appearance A set of wooden stairs leading up at a steep angle, at least 20 feet long.

Trigger A creature steps on the second step from the top.

Detection A successful DC 13 Wisdom (Perception) check reveals the trap.

Disarming or Destroying A successful DC 12 Dexterity check using thieves’ tools disables it. The trap can be destroyed by damaging the triggering step. This step has an AC of 8 and 10 hits points. If it is not destroyed in a single successful hit, it will activate the trap.

Damage and Effects When a creature steps on the “trigger step”, which is the second step from the top, the trap activates and every step on the stairs rotates and reveals razor-sharp blades mounted on them. Each step is now at an angle causing every creature to slide down the stairs, taking damage from each individual set of blades. The amount of damage varies by creature position.

Creatures in the bottom 5 feet of the stairs take no damage as they jump off the stairs.

Creatures above take 3 (1d6) slashing damage per 5 feet that they slide down and do not ignore the last 5 feet (on a typical set of stairs, that is 12 (4d6) slashing damage for sliding 20 feet down). The creatures must make a DC 12 Dexterity saving throw taking full damage on a failed save, or half as much damage on a successful one.

As soon as there are no more creatures on the stairs, the trap resets.

Fire Jets CR 4

Simple magical OR mechanical trap

Appearance Holes in the walls or nearby statues show a slight bit of charring from heavy flames at some point in the past.

Trigger A creature steps on a hidden pressure plate or activation tile, releasing gouts of flame from the nearby holes (often camouflaged as the mouth of statues).

Detection A successful DC 15 Wisdom (Perception) reveals the pressure plate or activation tile.

Detect magic reveals an aura of evocation magic from the statues (though this only applies to the magical version of trap).

Disarming or Destroying A successful DC 15 Dexterity check using thieves’ tools cuts or disables the pressure plate for the mechanical trap. For the magical version of the trap a successful dispel magic (DC 13) cast on the statue or the activation tile destroys the trap.

Damage and Effects When activated by a weight of more than 20 pounds, the fire holes (mouth of the statues if such are present) release a 30-foot cone of fire.

Each creature in the fire must make a DC 13 Dexterity saving throw, taking 22 (4d10) fire damage on a failed save, or half as much on a successful one.

Dead Heads CR 4

Simple magical trap

Appearance A corridor, 80-feet long by 5-feet wide by 15-feet high. There is a lit torch at the start and end of the corridor.

Trigger A pressure plate 50 feet down the corridor opens the hidden trapdoor in the ceiling and activates the magical rune inscribed underneath it.

Detection A successful DC 15 Wisdom (Perception) or Intelligence (Investigation) check will reveal the pressure plate on the floor or the trapdoor in the ceiling. Detect magic reveals a faint aura of necromantic magic around the edges of the pressure plate. Detect magic reveals an aura of necromancy magic emanating from the ceiling.

Disarming or Destroying A successful DC 15 Dexterity check using thieves’ tools will disarm the trap as the hero wedges the pressure plate in place. Dispel magic (DC 12) destroys the magical rune, but has no effect on the trapdoor.

Damage and Effects Necromantic magic imbues the twelve preserved heads hidden in the ceiling with a semblance of life for 1 round. As the trapdoor opens, the heads fall to the floor, attempting to bite the nearest creature on the way down.

If a creature is between 30 and 50 feet into the corridor, one falling head will attempt to bite it. Each head makes a melee attack with a +8 bonus. It deals 2 (1d4) piercing damage plus 9 (2d8) poison damage.

If the magical rune is dispelled but the trapdoor is still triggered, the twelve heads fall to the floor and all creatures 30 to 50 feet into the corridor must make a DC 10 Dexterity save or be struck by a falling head for 1 point of bludgeoning damage.

Dead Herring CR 4

Simple mechanical trap

Appearance A corpse lies rotting on the floor. At first glance, it appears to be garbed in fine quality clothing and the hilt of a long sword sticks out from underneath the body.

Trigger Jostling the body to loot or move it causes the dagger concealed under the body to slice open the bladder, releasing the poison.

Detection A successful DC 15 Wisdom (Perception) check notices the unusual angle at which the body is resting — almost as though it is posed.

Disarming or Destroying A successful DC 13 Dexterity check disarms the trap as the hero prevents the alchemical reagents from mixing. Anyone using alchemist’s supplies to disarm the trap gains advantage on the check.

Damage and Effects When the liquid alchemical component seeps from its container, it mixes with the powdered alchemical component on the floor below it and produces poisonous gas fumes. All creatures within a 15-foot-radius of the corpse must make a DC 13 Constitution saving throw.

On a failed save, the creature takes 16 (4d6) poison damage and is poisoned for 1 hour. On a successful save, the creature takes half as much damage and is not poisoned.

Greedy Fountain CR 4

Simple magical trap

Appearance A functioning water fountain where gold coins can be seen at the bottom.

Trigger Any living creature that is adjacent to the fountain hears a magical suggestion in their mind.

Detection A successful DC 15 Wisdom (Perception), Intelligence (Investigation), or DC 15 Intelligence (Arcana) check reveals the presence of sigils painted onto the inside bowl of the fountain under the shallow water. Detect magic reveals auras of enchantment, illusion, and conjuration around the fountain.

Disarming or Destroying A DC 15 Intelligence (Arcana) check reveals that the trap can be destroyed by physically damaging the bowl of the fountain, which has an AC of 10 and 5 hit points, cracking and destroying the magical script. Dispel magic (DC 15) dispels the magical sigils.

Damage and Effects A creature adjacent to the fountain hears the following words (spoken in their native tongue) in their mind: “Place your weapons in the fountain.” If the creature can’t be charmed, it is immune to the effects. Otherwise, it must make a DC 16 Wisdom saving throw. On a failed save, the creature must immediately spend 1 round putting any handheld weapon(s) and up to two sheathed weapons it may have into the fountain. At the end of the round, any weapons the creature deposited in the fountain are teleported away to a locked chest within 100 feet.

The coins at the bottom of the fountain are illusory.

Sandwiched In Stone CR 4

Simple mechanical trap

Appearance An unlit 10-foot long by 5-foot wide underground hallway with a closed door at the end. The walls and floor of this hallway are made of rough, unworked stone. The unworked nature of the floor results in uneven areas of elevation and occasional small rocks dotting the path— the floor is difficult terrain.

Trigger Touching and turning the unlocked door’s handle.

Detection A successful DC 10 Wisdom (Perception) check reveals the slight smell of rotting garbage tinged with sulfuric acid typical of crawler mucus coming from the door handle. Additionally, a successful DC 13 Wisdom (Perception) check reveals thin tracks embedded in the natural stone ceiling and floor that run from both sides of the walls into the center of the room.

Disarming or Destroying A successful DC 10 Dexterity check allows a creature to wipe the carrion crawler mucus off the door handle without poisoning itself. A successful DC 15 Dexterity check using thieves’ tools allows the hero to jamb the tracks to keep the crushing stones at bay.

Damage and Effects A creature subjected to the poison must succeed on a DC 13 Constitution saving throw or be poisoned for 1 minute. The poisoned creature is paralyzed. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

As the door handle turns, 2-foot sections of wall (one on each side of the hall) slide along the tracks and slam together in the center of the hallway, crushing any creature standing in front of the door before retracting and resuming their original position. A mobile (non-paralyzed) creature that is standing in front of the door when this occurs can make a DC 10 Dexterity saving throw. The creature takes 22 (4d10) bludgeoning damage on a failed save, or half as much on a successful save.

Bard’s Bane CR 5

Simple mechanical trap

Appearance A finely crafted harp.

Trigger One string is off-key, and when its hollowedout tuning head is turned, the poison dust stored within is released.

Detection Because the poison dust is minuscule in size and weight and it is concealed within the tuning head, it is very difficult to detect.

A successful DC 20 Wisdom (Perception) or Intelligence (Investigation) check reveals a pinsized hole in the tuning head.

Disarming or Destroying A successful DC 10 Dexterity check using thieves’ tools will plug the hole and keep the dust from contaminating the harp.

Damage and Effects Once the trap is triggered, a few particles of poison dust (invisible to the naked eye) trickle down and coat the out-of-tune string. The poison remains potent until it is absorbed by contact with skin. When the string is plucked, the player of the harp must make a DC 15 Constitution saving throw. On a successful save, the creature takes 22 (4d10) necrotic damage or half as much on a failed save. The tuning head holds one dose of poison.

Spear Trap CR 5 — 6

Simple mechanical trap

Appearance Two lattice works made from spears spring from either side of a corridor when a beam of light is crossed.

Trigger A creature or object that’s Small or bigger passed through a beam of light.

Detection A successful DC 13 Wisdom (Perception) check reveals the presence of the trap, and that it’s activated by moving through the beam of light.

Disarming or Destroying A successful DC 15 Dexterity check using thieves’ tools disarms the trap. Anyone without thieves’ tools can attempt to disarm the trap, but they have disadvantage when doing so.

Failing the check triggers the trap.

Damage and Effects When triggered, the spears shoot out from either side, with 5 (1d10) spears attacking the triggering creature. Each spear makes a melee attack with a +8 bonus. The triggering creature takes 4 (1d8) piercing damage from each spear that hits.

Some of these traps are poisoned (adding 1 to the CR), in which case any creature hit must succeed on a DC 15 Constitution saving throw, taking 11 (2d10) poison damage on a failed save, or half as much damage on a successful one.

The trap resets on the following round.

GM’s Note: This is the trap you see on the front of this book.

Suffocating Room CR 5

Simple mechanical trap

Appearance An underground complex where the rooms are carved into the stone. The door to a 15-foot square library stands open. A rocking chair, a bearskin rug, and a pedestal with a pipe, a pewter goblet, and an empty glass decanter resting upon it occupy the center of the room.

The walls to the right and left and opposite the door are covered from floor to ceiling with bookcases packed with books.

Trigger When the heavy pewter chalice is moved, the switch that it depresses will pop up and trigger the air removal trap sequence.

Detection A successful DC 15 Wisdom (Perception) or Intelligence (Investigation) check reveals scuff marks on the floor just inside the room’s threshold in front of the door. If a creature examines the bookcase behind the books, a successful DC 15 Intelligence (Investigation) check reveals numerous pinhead-sized holes bored into the wooden bookcase that continue through the stone wall behind it.

Disarming or Destroying A successful DC 15 Dexterity check allows a creature to substitute an appropriately weighted object for the chalice so that the switch remains depressed, keeping the trap from triggering. Alternatively, a successful DC 10 Dexterity check using thieves’ tools made in conjunction with a DC 15 Intelligence (Investigation) check to find and plug all of the tiny holes will keep the air from being sucked out of the room.

Damage and Effects As the trigger switch activates, a panel of the stone wall to the left of the door slides in front of the door making an airtight seal and the mechanisms hidden within the walls simultaneously suck the air from the room. It takes 1 minute before all the air is sucked from the room. At that time, creatures in the room are subject to suffocation.

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, 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.

The stone panel barring the exit has an AC 17 and 510 hit points. It has immunity to cold, fire, poison, psychic, radiant, slashing, and thunder damage and resistance to necrotic damage.

Swinging Blades CR 5

Simple mechanical trap

Appearance Large blades, shaped like crescent axes, swing like pendulums across a corridor, cutting any creatures caught in it to shreds.

Trigger Activated by pulling a lever or by stepping on a pressure plate in the middle of the area of effect, attacking any creatures in an area 10 feet ahead and behind the activating creature.

Detection A successful DC 15 Wisdom (Perception) check reveals the location of the lever, which is normally somewhat out of sight (but normally within 100 feet) of the pressure plate.

Disarming or Destroying A successful DC 15 Dexterity check using thieves’ tools disables the lever (if the person attempting it can reach the lever) or the pressure plate.

Damage and Effects All Medium or larger creatures within a 5-footwide and 20-foot-long area must make a DC 15 Dexterity saving throw or take 14 (4d6) slashing damage on a failed save, or half as much damage on a successful one. The damage continues each round following activation unless the trap is turned off or disabled.

If triggered by the pressure plate, the area of effect is centered on the pressure plate itself.

Divide & Conquer CR 6

Simple magical trap

Appearance A metal chest secured with an average lock requiring a DC 10 Dexterity check using thieves’ tools to open.

Trigger The chest holds four ornate chalices which rest atop a false bottom. A successful DC 5 Wisdom (Perception) or Intelligence (Investigation) check reveals the false bottom. The top panel (or lid) of the false bottom is made of a thin sheet of lead. A magical insignia is penned on the underside of it. Opening the false bottom changes the orientation of the insignia from horizontal to vertical. This change in orientation triggers a teleportation spell.

Detection Because the insignia is inscribed on the inside of an object, it is not readily visible, so it cannot be detected until triggered. A successful DC 15 Wisdom (Perception) or Intelligence (Investigation) check reveals the magical insignia only if these checks are made in conjunction with magic. Detect magic does not function in this case because of the thin sheet of lead. If a creature that is aware of the lead sheet makes a successful DC 15 Intelligence (Arcana) check, they determine that a magical trap or valuable magic item may be underneath.

Disarming or Destroying Dispel magic (DC 16) destroys the insignia.

Damage and Effects One random creature in contact with the lead panel when the trap is triggered is teleported into a stone sarcophagus located in a different location within 100 feet. The sarcophagus can accommodate a Large or smaller creature.

Any creature that doesn’t fit these parameters is immediately shunted out of the coffin and suffers 22 (4d10) force damage. The stone panels of the sarcophagus are 4 inches thick.

The sarcophagus has 50 HP, a 17 AC, and resistance to acid and piercing damage. It has immunity to cold, fire, necrotic, poison, psychic, radiant, and slashing damage. A successful DC 20 Strength (Athletics) check will slide the stone cover off. A creature inside the sarcophagus suffers a -2 penalty on the check due to the cramped space. After 4 hours, air runs out in the sarcophagus and a creature inside begins to suffocate.

Drowning Tentacles CR 6

Complex magical trap

Appearance A magical sigil on the bucket is activated by being disturbed, summoning tentacles that attack any creatures adjacent to the well. They attempt to drag the hero down and drown them.

Trigger The hemp fibers of the rope are woven in a pattern that forms a magical sigil. When the windlass is operated to lower the bucket, the sigil is activated and the spell is completed.

Detection A successful DC 15 Wisdom (Perception) or Intelligence (Arcana) check reveals the magical sigil. Detect magic reveals an aura of conjuration magic on the rope.

Initiative The tentacles act on initiative 20.

Active Elements Three rubbery tentacles reach up from the water in the well and randomly attempt to grab a creature in a square adjacent to the well. A targeted creature must succeed on a DC 15 Dexterity saving throw or take 16 (4d6) bludgeoning damage and be restrained by the tentacle.

Dynamic Elements Once a tentacle has restrained a target, it will retract on the next round, dragging the target underwater. On all subsequent rounds, the target automatically takes 16 (4d6) bludgeoning damage until the tentacles disappear or the 227277 target frees itself from the tentacles (whichever comes first). A creature restrained by the tentacles can use its action to make a DC 15 Strength (Athletics) or Dexterity (Acrobatics) check (its choice). On a success, it frees itself.

Constant Elements While restrained by the tentacles, the grabbed creature is dragged into the well and starts to drown. While a creature can normally hold its breath for a number of minutes equal to 1 + Conbonus, due to the strangling nature and tossing and twisting from the tentacles, this is reduced to a number of rounds equal to 3 + Conbonus.

Disarming or Destroying Dispel magic (DC 15) destroys the sigil. A successful DC 16 Intelligence (Arcana) check also destroys the sigil as the hero snips the rope fibers, unraveling the sigil. Failing the check triggers the trap.

last for 1 minute, after which time they dissolve harmlessly into water. The tentacles can’t be dispelled with dispel magic and are immune to all forms of damage except cold. Taking 5 points of cold damage immobilizes a tentacle (which has AC 10 and 30 hit points) for 1 round which prevents it from squeezing a creature and grants the creature advantage on its Strength or Dexterity check made to free itself.

Dumbwaiter Disaster CR 6

Simple mechanical trap

Appearance A set of muddy footprints belonging to a barefoot humanoid leads up and into a dumbwaiter but the dumbwaiter is currently empty. The dumbwaiter is large enough to accommodate a Small creature and the ropes for operating it on either side are intact.

Trigger Raising the two-story dumbwaiter.

Detection A successful DC 20 Wisdom (Perception) check reveals the remnants of a fine dust below the dumbwaiter where the base of the wall and the floor meet. The mechanism that houses and triggers the trap is behind the dumbwaiter box in the shaft and can’t be inspected by normal means while the dumbwaiter is on the first floor.

There is a 1-inch gap between the inner box and the outer wall of the shaft that would allow something minuscule to fit through such as an arcane eye. This strategy would allow the caster to look behind the inner box of the dumbwaiter and see the hook and the outline of the sliding door in the shaft that contains the hammer.

Disarming or Destroying When the inner box housing of the dumbwaiter is raised, a hook on the back of the box lifts a panel in the shaft that releases a spring-loaded hammer attached to a vial of blinding dust.

When the hammer slams down onto the shelf at the base of the dumbwaiter, the vial explodes, dispersing the blinding powder into the 5-foot space adjacent to the dumbwaiter. A successful DC 15 Dexterity check using thieves’ tools allows a creature to deconstruct the inner box housing of the dumbwaiter. Failing to disarm the trap triggers it.

Damage and Effects Any creatures in the 5-foot square adjacent to the dumbwaiter opening when the vial of blinding powder shatters must make a DC 13 Dexterity saving throw. A creature gains the blinded condition for 1 hour and takes 22 (4d10) slashing and piercing damage from tiny slivers of glass and chalk dust that coat their eyes and throat on a failed save. On a successful save, a creature takes half as much damage and is not blinded.

Roof Collapse CR 6

Simple mechanical trap

Appearance An unstable section of the ceiling is held up with rudimentary supports.

Trigger A creature moves a tripwire stretched across the ground between two support beams that are set very loosely, dislodging them.

Detection A successful DC 10 Wisdom (Perception) reveals the tripwire.

Disarming or Destroying A successful DC 15 Dexterity check using thieves’ tools cuts or disables the trip wire safely (the person making the check can reset the trap if they wish). Anyone with an edged weapon or tool can attempt the check, but they have disadvantage when doing so. Failing the check triggers the trap.

Damage and Effects When triggered, the ceiling collapses and any creature in the area (typically a 20-foot deep area that’s as wide as the room or corridor) beneath the unstable ceiling must attempt a DC 15 Dexterity saving throw, taking 22 (4d10) bludgeoning damage on a failed save, or half as much damage on a successful one. Once the trap is triggered, the floor of the area is filled with rubble and becomes difficult terrain.

GM’s note: Some of these traps drop far more debris than normal, as they are intended to collapse the tunnel, blocking off any entry completely. These traps deal 44 (8d10) bludgeoning damage on a failed save, or half as much on a successful one. When triggered, the area under the collapsed ceiling becomes impassable terrain. This version of the trap has a CR of 8.

This particular trap can also be used to simulate natural hazards such as mineshaft cave-ins or tumbling rocks on a mountainside.

Screaming Book CR 6

Simple magical trap

Appearance A tattered ledger or diary on the table. It has no title, but a pen and vial of ink rest on the table beside the book.

Trigger Exposing the magical inscription on the first page by opening the book.

Detection Detect magic reveals an aura of evocation magic around the book.

Disarming or Destroying Dispel magic (DC 13) destroys the magical inscription.

Damage and Effects A loud boom rips from the pages. All creatures within a 20-foot-radius must make a DC 15 Constitution saving throw. On a failed save, a creature takes 16 (4d6) thunder damage and is deafened for 1 hour. On a successful save, the creature takes half as much damage and is not deafened.

GM’s Note: This trap is often used to alert sentries posted nearby of the presence of intruders.

Rust Dust CR 7

Simple mechanical trap

Appearance An underground cavern.

Trigger A trip wire strung between two boulders is rigged to release a net overhead.

Detection A successful DC 15 Wisdom (Perception) check reveals the trip wire and the net.

Disarming or Destroying A successful DC 15 Dexterity check using thieves’ tools disables the trip wire without causing the net to drop.

Damage and Effects The net is coated with rust dust and covers a 10-foot-by-10-foot area centered on the trip wire. Any creature within this area must succeed on a DC 15 Dexterity saving throw or be restrained.

Rust dust affected any nonmagical ferrous metal items worn or carried such as armor, shields, weapons, etc, automatically suffer a penalty at the start of every round that a creature is restrained in the net. Armor and shields suffer a permanent and cumulative -1 penalty to the AC they provide. Armor reduced to an AC of 10 is destroyed. A shield that drops to a +0 bonus is destroyed. Weapons take a permanent and cumulative -1 penalty to damage rolls. If a weapon’s penalty drops to -5, the weapon is destroyed.

Using an action to make a DC 10 Strength (Athletics) check successfully frees a creature from the net. Dealing at least 5 points of slashing damage (AC 10) to the net where it is in contact with a creature, frees the creature, though a metal weapon used for this purpose suffers the -1 penalty even if it’s being used by a creature outside of the net.

The Demon’s Gaze CR 7

Simple magical trap

Appearance Two demonic statues line the walls with one on either side of the corridor. The statues do not face each other but are set 5 feet above one another, each staring into the wall on the other side. Solid blue beams emanate from the eyes of one, while solid red beams emanate from the other.

Trigger A creature passes through one of the beams.

Detection A successful DC 14 Wisdom (Perception) check reveals that where the blue beams hit the wall there is a smattering of ice. Where the red beams hit the wall, there is scorching from fire.

Disarming or Destroying The trap cannot be disarmed through physical means, but can (temporarily) be disarmed through the use of dispel magic (DC 15). This subdues the trap for an hour.

A DC 17 Intelligence (Arcana) check reveals that the beams can be safely passed through if a creature touches both beams at once.

Damage and Effects Any creature passing through a beam must make a DC 14 Reflex saving throw. A target takes 8d6 damage on a failed save, or half as much damage on a successful one. The damage taken depends on the beam crossed: crossing the blue beam deals cold damage, crossing the red beam deals fire damage.

If a creature passes through both beams at once, no damage is taken.

Snake Room CR 8

Complex mechanical trap

Appearance An empty room, 10-foot-by-10-foot, with two doors and no ornamentation. Dozens of slightly indented holes can be seen along the top of each of the four walls.

Trigger A minimum of two creatures enter the room, triggering the pressure plate underneath the room.

The doors lock when triggered by the pressure plate, after which the room floods with 4 poisonous snake swarmsMM. These swarms fill up every available space in the room, allowing them to attack any creature in the room.

This trap must be reset manually, such as by a druid using speak with animals.

Initiative The doors lock on initiative 20.

The snake holes open on initiative 15, and the swarms attack on initiative 15.

Detection A successful DC 15 Wisdom (Perception) check reveals the trap.

Active Elements Lock Doors: The door(s) to this room slam shut and are locked in place. This effect activates only once, the first time the trap is triggered.

Snake Holes: The snake holes open, allowing the swarms to flood in. This effect activates only once, the first time the trap is triggered.

Swarms: The poisonous snake swarm spends the first round filling up the room (and doing no damage).

Dynamic Elements The swarms attack each round after the first one, acting on initiative 15.

Constant Elements There are no constant elements to this trap.

Disarming or Destroying A successful DC 14 Dexterity check using thieves’ tools disables the trap by breaking the pressure plate. The doors are locked but can be opened with a DC 15 Dexterity check using thieves’ tools. The doors have an of AC 15 and 18 hit points and can be forced open with a DC 16 Strength (Athletics) check. Alternatively, the snakes can be calmed with a successful DC 18 Wisdom (Handle Animal). Anyone casting speak with animals gains advantage on this check.

Diseased Darts CR 9

Simple magical trap

Appearance A ceramic tile mosaic covers the north wall of a 20-foot-square room.

Trigger A living creature approaching within 5 feet of the mosaic.

Detection A DC 15 Wisdom (Perception) check reveals that the mosaic is tied to a trap, but not how.

A successful DC 17 Intelligence (Arcana) check reveals that certain religious sects use rituals to imbue likenesses of their deities with magical power. Detect magic reveals an aura of divination and evocation magic on the mural.

A successful DC 17 Intelligence (Religion) check will reveal that the mosaic is in the form of a deity of disease and pestilence. Detect magic reveals an aura of evocation magic on the centered on the mosaic.

Disarming or Destroying A successful DC 15 Intelligence (Arcana) check reveals that a hallow spell counteracts the ritual magic used to create these mosaics.

Dispel magic (DC 16) destroys the mosaic.

Damage and Effects A creature with a good facet in their alignment that approaches within 5 feet of the mosaic will be targeted by a barrage of magical darts of force and disease that automatically strike.

The target takes 49 (11d8) force damage and is afflicted with cackle fever.

Once the trap is triggered, it must be reconsecrated to function again.

Fiery Portrait CR 10

Simple magical trap

Appearance A high-quality painted portrait whose eyes follow anyone watching the painting. An inner glow illuminates the eyes, occasionally flaring as if firelight was reflected in them.

Trigger A creature walks within 5 feet of the portrait and looks it in the eyes.

Detection A successful DC 15 Wisdom (Perception) check reveals the trap. Detect magic reveals an aura of evocation magic on the portrait.

Disarming or Destroying The trap cannot be disabled, but destroying it is easy. It has AC 5 and 8 hit points and is vulnerable to slashing and fire.

Damage and Effects Any creature within line of sight of the portrait must make a DC 15 Dexterity saving throw as they are enveloped in a pillar of fire. Each creature takes 24 (8d6) fire damage on a failed save, or half as much on a successful one.

Creatures that fail the saving throw also catch fire taking 3 (1d6) damage at the start of its turn until they or an ally take an action to douse the fire.

Once the trap has been triggered, the person in the portrait fades from view and the trap becomes inactive. The person reappears an hour later, after which the trap becomes active once more.

Impaling Stalactite CR 10

Simple magical trap

Appearance A natural, underground cavern has stalactites on the ceiling 50 feet above and stalagmites with loose rubble on the floor creating difficult terrain.

Trigger Stepping on a magical engraving carved into the floor, which is concealed under sand and pebbles, triggers the trap.

Detection A successful DC 17 Wisdom (Perception) or Intelligence (Arcana) check reveals the magical engraving. Detect magic reveals an aura of transmutation magic on the floor.

Disarming or Destroying Dispel magic (DC 16) destroys the magical engraving. A successful DC 17 Intelligence (Arcana) check also destroys the magical engraving as the hero chisels away at the engraving, successfully siphoning away its power without triggering it.

Damage and Effects As soon as a creature steps on the magical engraving, gravity is reversed in that 5-foot square and the triggering creature falls upward for 50 feet until it hits the ceiling. The creature can make a DC 15 Dexterity saving throw to avoid being impaled upon the stalactite directly above. On a successful save, the creature slams into the ceiling and takes 24 (6d6) bludgeoning damage. On a failed save, the creature takes the bludgeoning damage and an additional 12 (3d6) piercing damage as it is also impaled by a stalactite. Whether the creature is impaled or not, it immediately falls back down as the effect abruptly ends. The creature can make a DC 20 Dexterity (Acrobatics) check to roll with the fall. It takes 24 (6d6) bludgeoning damage on a failed save, or half as much on a successful one.

Mass Electrocution CR 10

Simple magical trap

Appearance An unlit hallway, 5-feet wide by 100-feet long, has an area of flooring that is an inch lower than the rest. The first 10 feet on either end of the hallway is not depressed, leaving the rest of the hallway 1-inch lower than the standard floor level. A crack on the right hand wall allows brackish water to slowly seep onto the floor.

Another crack on the left hand side of the hall allows the water to drain, keeping the hall from flooding, but leaving the depressed area with 1 inch of constant standing water.

Trigger A creature approaches within 10 feet of the glyph of warding spell that is inscribed on the tile floor 50 feet into the hallway.

Detection A successful DC 5 Wisdom (Perception) or Intelligence (Investigation) check reveals the cracks and the uneven floor. Anyone making a successful DC 15 Wisdom (Perception) or Intelligence (Investigation) realizes that the water is actually coming in from the cracks, rather than draining out.

The glyph is inscribed on the floor under water and needs to be spotted ten feet away which adds to the difficulty of detecting the trap. A successful DC 17 Wisdom (Perception) or Intelligence (Arcana) check reveals the magical glyph. Detect magic reveals an aura of abjuration magic in a 10-foot radius of where the glyph is inscribed.

Disarming or Destroying Dispel magic (DC 17) destroys the glyph. A successful DC 17 Intelligence (Arcana) ability check also destroys the glyph as the hero unravels part of the magic pattern of the glyph.

Damage and Effects The glyph of warding was crafted using the explosive runes with the lightning option.

All creatures standing in the water when the glyph is triggered must make a Constitution saving throw DC 17. A creature takes 45 (10d8) lightning damage on a failed saving throw, or half as much damage on a successful one.

Rolling Boulder CR 10

Simple mechanical trap

Appearance A narrow tunnel, just over 10 feet wide, with a trapdoor in the ceiling from which rolls a 10- foot diameter boulder, crushing everything in its path.

Trigger When more than 20 pounds of weight is placed on the pressure plate.

Detection A successful DC 15 Wisdom (Perception) check reveals the pressure plate and the trapdoor in the ceiling or the streaks on the walls or floor where the boulder has passed by previously.

Disarming or Destroying Disarming the trap can be done by jamming a spike under the pressure plate or similar.

This can be done with a DC 15 Dexterity check. If using thieves’ tools or you have the Stonecunning racial ability, you gain advantage on the check. If it fails, you automatically trigger the trap.

Damage and Effects When activated every creature in the path of the boulder must make an Initiative check. The boulder rolls initiative with a +8 bonus, and on its turn it moves 60 feet in a straight line away from the trapdoor. The boulder can move through creatures’ spaces, and creatures can move through its space, treating it as difficult terrain.

Whenever the boulder enters a creature’s space or a creature enters its space while it’s rolling, that creature must succeed on a DC 15 Dexterity saving throw or take 55 (10d10) bludgeoning damage and be knocked prone.

The boulder stops when it hits a wall or similar barrier and cannot go around corners, but it can do gentle curving turns if the walls are built to guide such movement.

As an action, a creature within 5 feet of the boulder can attempt to slow it down with a DC 20 Strength (Athletics) check. On a successful check, the boulder’s speed is reduced by 15 feet and the damage is reduced by 11 (2d10).

If the boulder’s speed is reduced to 0, it stops moving and is no longer a threat, though it may still block the entrance to the area behind it.

GM’s Note: Some trap makers use a hollow steel ball instead of a stone boulder. This is fitted with sharpened spikes that retract once enough weight is on them (more than 1,000 pounds). These spikes deal a further 22 (4d10) slashing damage to anyone in the boulder’s path. This damage is not reduced by a successful Dexterity check (this increases the trap’s CR to 12).

Mirage Menaces CR 12

Simple magical trap

Appearance A hall or room filled with hundreds of mirrors.

When a creature enters, the door slams shut, revealing a mirror on the inside of it too.

Duplicates of the triggering creature then emerge from the mirrors, attacking it.

Trigger A creature stands in or walks past the center of the room.

Detection A successful DC 15 Wisdom (Perception) check reveals that the door will slam shut when a creature stands in the middle of the room, but not the rest of the nature of the trap.

Discovering this before it activates requires a successful DC 16 Intelligence (Arcana) check.

Detect magic reveals an aura of illusion magic on each of the mirrors.

Disarming or Destroying The trap cannot be disarmed through physical means, but can (temporarily) be disarmed through the use of dispel magic (DC 17). This subdues the trap for 24 hours.

The mirrors can be destroyed, but at least 10 mirrors must be destroyed before the mirrors cease functioning. The mirrors have AC 8 and 10 hit points. Any broken mirrors reform in 24 hours.

Damage and Effects When triggered, 5 doppelgangersMM appear from the mirrors, taking the exact shape of the triggering creature. These creatures attempt to slay the triggering creature, but if killed they simply vanish into smoke, and the mirror that they emerged from turns dark, showing a reflection of the triggering creature lying dead in a coffin.

Once all five creatures are killed, the Hall of Mirrors becomes inactive for 24 hours.

Caught Red-Handed CR 12

Simple magical trap

Appearance A dressing room containing a vanity with a mirror and a cushioned bench. Several containers of makeup, a bottle of perfume, and a jewelry box rest upon the vanity. Three mannequins stand in various poses. Each mannequin has a wig on its head, a neckerchief at its throat, a bracelet on its wrist, and one or more rings (each with a different gemstone) on each hand.

Trigger Exposing the magical glyph inscribed on the mannequin’s finger by removing the ruby ring covering it.

Detection Because the glyph is inscribed on the finger under the ruby ring, it is not visible for inspection without moving the ring. An arcanist’s magic aura spell has been cast on the glyph to mask its magic, making it appear to be nonmagical.

GM’s Note: If a creature wants to make a visual inspection of the jewelry without handling it, A successful DC 20 Intelligence check reveals that the jewelry on display is costume jewelry.

Disarming or Destroying If dispel magic (DC 16) is cast on the trapped mannequin, it will automatically dispel the arcanist’s magic aura spell first, leaving the glyph active. A second dispel magic (DC 16) is required to dispel the glyph.

If a creature uses detect magic again, they notice that there is still an aura of abjuration magic emanating from the finger.

Damage and Effects As the ruby ring is taken off the mannequin’s finger a disintegrate spell targets the creature triggering the trap. The targeted creature must make a DC 16 Dexterity saving throw. On a failed save, the target takes 75 (10d6 + 40) force damage. The target is disintegrated if this damage leaves it with 0 hit points.

Raining Fire & Acid CR 14

Simple mechanical trap

Appearance An unlit hallway that is 40-feet long by 10-feet wide with a 25-foot high ceiling. Its floor tiles are made from alternating quartzite and granite tiles, forming a checkerboard pattern, and its walls consist of roughly-worked stone blocks with significant natural texture.

Trigger Twenty feet into the hallway, both 5×5 foot tiles in that line of the floor pattern act as pressure plates that will activate when 20 pounds of pressure is applied to them.

Detection A creature studying the ceiling will notice a cloth (camouflaged to appear as the stone ceiling) stretched across the ceiling with a successful DC 15 Wisdom (Perception) check.

A creature studying the flooring at 20 feet into the hallway will notice the two pressure plates with a successful DC 15 Wisdom (Perception) check.

Disarming or Destroying A successful DC 17 Dexterity check using thieves’ tools will disarm the trap as the hero uses wedges to keep the pressure plates from depressing.

Damage and Effects When the pressure plates activate, they release spring-loaded knives in the ceiling that cut the strings which secure the camouflaged cloth stretched across the ceiling. As the lines holding the camouflaged cloth are cut, the hidden glass bottles of alchemical reactants that were sitting on the cloth plummet to the floor. When the glass shatters and the chemical compounds mix, fire and acid bombs explode across the entire hall. Creatures in the area of effect must make a DC 17 Dexterity check.

On a failed save, a creature takes 14 (4d6) fire damage, 14 (4d6) acid damage, and 14 (4d6) piercing damage, or half as much on a successful save.

Curiosity Killed The Cat CR 15

Simple magical trap

Appearance A closed, sturdy, iron door.

Trigger A creature’s reflection in the mirror (mounted on the wall behind the false door) triggers the magical trap.

Detection A successful DC 20 Intelligence (Investigation) check reveals that a thin piece of paper pushed under the door is stopped by an obstacle which indicates something unusual, but not the exact nature of the trap. Detect magic can’t reveal the magical inscription on the back of the mirror because it is located behind the 1-inch thick iron door. If a creature employs magic that allows them to see through objects in conjunction with a successful DC 20 Wisdom (Perception) check, they discover a magical inscription on the back of the mirror. They will also see that there is only stone, but no room behind the false door.

Disarming or Destroying Destroying the mirror is a simple matter of smashing it, but it must be done without showing your reflection. The mirror has an AC of 5 and 8 hit points. Dispel magic (DC 18) destroys the trap.

Damage and Effects A feeblemind (DC 18) spell targets the first creature reflected in the mirror.

Wheel of Death CR 16

Complex magical and mechanical trap (CR 16)

Appearance A 20-foot circular room with a single 3-foot high pillar in the middle, on which is placed a darkgray stone.

Trigger 2 rounds after a creature steps into the room.

Detection A successful DC 18 Wisdom (Perception) check reveals that the room itself is trapped, and reveals grooves and scrapes along the walls.

Detect magic reveals an aura of transmutation magic on the stone.

Initiative The doors lock on initiative 20.

Each of the walls of blades acts on an initiative of 15.

The gravity stone in the middle of the room acts on an initiative of 5.

Active Elements Lock Doors: The door(s) to this room slam shut and are locked in place, requiring a DC 20 Dexterity check using thieves’ tools to open.

This effect activates only once, the first time the trap is triggered.

Damage and Effects Two rounds after a creature enters the room the door(s) slam shut and 4 longswords emerge from each of the walls. The walls then start spinning at great speeds, while the dark stone in the middle starts emitting pulses that push living creatures out towards the walls.

This continues for 5 rounds, or until every creature in the room is dead, or the trap is disabled or destroyed, depending on what comes first.

GM’s note: Cleaning the room or disabling the trap for an owner is a simple matter of putting a cloth infused with lead over the stone in the room.

Wall Blades: The walls of blades start spinning up to speed. The longswords attack anyone within 5 feet of them. Each set of swords has a +10 bonus to the attack roll and deals 18 (4d8) slashing damage.

Gravity Stone: Each creature in the room must make a DC 18 Strength saving throw. On a successful save, the creature takes no damage and is moved 5 feet towards the walls. On a failed save, the creature is flung all the way out, ending up adjacent to the nearest wall.

Dynamic Elements Each round, for the next 4 rounds, the blades spin faster, increasing the damage by 1d8, to a max of 4d8.

Constant Elements Any creature that ends its turn within 5 feet of any of the walls are attacked as per the active Wall Blades.

Disarming or Destroying A successful DC 20 Dexterity check using thieves’ tools disables it. The trap can be destroyed by dealing 30 points of damage to it. It has an AC of 17. Each successful check disables one of the “wall blades”. Each of the 4 wall blades must be disabled or destroyed individually.

Alternatively, by succeeding on a DC 15 Intelligence (Arcana) check, the hero realizes that the trap can be disabled by putting a leadlined cloth over the gravity stone.

Hazards

Unlike traps, hazards are usually not placed in a location on purpose but are a matter of chance.

Examples are dust storms, the arctic environment of a frost giant lair, or the disease-infused waste of a plague-ridden city. Most hazards of this type will be natural occurrences, though there are exceptions to this.

Hazard Name | CR – Challenge Rating

Description of trap type: hazard (natural and magical) or haunt

Appearance This describes what the hazard looks like, typically from the viewpoint of the heroes, though not always.

Trigger (only applies to haunts) This is how the haunt is activated.

Detection The DC for the Wisdom (Perception) check to find the hazard. In some cases, only parts of the hazard are revealed. Please also remember that a character who is deliberately searching could swap Intelligence (Investigation) for Wisdom (Perception), if the GM allows it for that specific situation.

Disarming and Destroying These are the steps that allow a hero to destroy a haunt. Most hazards cannot be destroyed, though they can be avoided.

Damage and Effects What the hazard does in mechanical terms when triggered.

Example Hazards

Sandstorm CR 1

Natural hazard

A billowing cloud of sand tears across the land, rending exposed flesh and getting in the eyes of everyone.

Sandstorms arise in arid lands where the vegetation is sparse and can come out of nowhere with even a mild breeze. Those sandstorms are usually annoying, but not terribly dangerous. The dangerous sandstorms come when the winds are at gale strength or higher, as the sand tears flesh and grinds down anything in its path.

Detection A DC 11 Wisdom (Perception) or Wisdom (Survival) check reveals the sandstorm is approaching 5 (1d10) minutes before it hits.

Damage and Effects A sandstorm reduces visibility to 25 (1d10 × 5) feet and gives disadvantage on Wisdom (Perception) checks that rely on sight. A sandstorm deals 3 (1d6) slashing damage per hour to any creatures within the area of effect (Which could be miles wide, depending on the size of the sandstorm). A successful DC 12 Constitution saving throw halves the damage.

A successful DC 12 Wisdom (Survival) check gives the person making the check and up to 5 other creatures advantage on the saving throw.

GM’s note: A magical variant of the sandstorm is the Storm of Teeth. This works in a similar manner to a sandstorm, but the damage is increased to 26 (4d12) slashing damage per hour, with a DC 14 Constitution saving throw to reduce the damage. This version is CR 4 instead.

Vampiric Brambles CR 2

Natural hazard

A large, green bush with sharp thorns. Several animal carcasses hang from the various branches of the bush.

Vampiric Brambles are a variant of the sundew plant that resembles a bush instead of a small plant. Its prey is also much larger than that of its insect-devouring cousin. The Vampiric Brambles prey upon mammals that pass through, catching them with their thorns and draining blood as nourishment.

Detection A DC 12 Wisdom (Perception) check reveals that the animals were drained of blood, though not that it was the plant that did it.

Damage and Effects Any living creature that passes through the thorns takes 3 (1d6) piercing damage from the thorns unless they are wearing armor with a greater AC than 15. Any creature that takes damage from the thorns is attacked by the vines of the plant. The vines attack each creature every round, with a +5 bonus to hit, dealing 6 (2d6) piercing damage and the target is grappled (escape DC 12). Until this grapple ends, the creature is restrained.

This continues until the Vampiric Brambles have killed one Medium-sized creature (or 2 Small-sized). Once that happens, the Vampiric Brambles are sated and go dormant for 7 days.

Flash Flood CR 3—4

Natural hazard

A wave of roiling water flattens everything in its path.

Heavy rains, flooding, and breaking dams can cause rivers, waterways, and sewers to break through the banks that contain them. These flash floods can catch the unwary and bury them in water, or even pummel them to death with debris.

Detection A DC 12 Wisdom (Perception) or Wisdom (Survival) check reveals that the flash food is rapidly approaching, giving creatures 2 (1d4) rounds to get to safety or prepare themselves.

Effects A flash flood sweeps past at a speed of 60 feet per round, with enough force to knock down trees, fences, throw boulders, and even destroy smaller buildings. Creatures within 50 feet of a flash flood must make a DC 12 Dexterity saving throw. A target takes 7 (2d6) bludgeoning damage on a failed save, or half as much damage on a successful one. Those who fail the saving throw are washed away in the current (moving 60 feet each round, alongside the flash flood), and take 7 (2d6) bludgeoning damage.

If they succeed on a DC 12 Strength (Athletics) check, they’re able to swim well enough that they avoid the damage, but to escape they must succeed on a DC 15 Strength (Athletics) check.

A flash flood lasts 10 (3d6) minutes, and creatures caught in the flood take damage each round until they escape or the flash flood subsides.

GM’s Note: Sewer floods are a variant of the flash flood that takes place in a sewer. Those who are caught in one of those must succeed on a DC 11 Constitution saving throw or become infected.

It takes 1d6 days for sewer plague’s symptoms to manifest in an infected creature. Symptoms include fatigue and cramps. The infected creature suffers one level of exhaustion, and it regains only half the normal number of hit points from spending Hit Dice and no hit points from finishing a long rest.

At the end of each long rest, an infected creature must make a DC 11 Constitution saving throw. On a failed save, the character gains one level of exhaustion. On a successful save, the character’s exhaustion level decreases by one level. If a successful saving throw reduces the infected creature’s level of exhaustion below 1, the creature recovers from the disease.

This increases the CR of the hazard to 4.

Avalanche CR 5

Natural Hazard

Heavy sheets of snow come tumbling down with a sound like crashing thunder. The air is thick with flying snowflakes, blocking sight, and the cold is numbing.

Avalanches are a deadly phenomenon found in ice and snow-covered mountains. When the snow gets disturbed, either from becoming too heavy from too much snow, or from outside disturbances like vibrations from footsteps or earthquakes, it comes rolling down the mountainside in heavy sheets, crushing all in its path, and trapping those that aren’t outright killed.

Detection A successful DC 11 Wisdom (Perception) check reveals the hazard before it triggers.

Effects Characters caught in the area of effect of the avalanche (which can be up to hundreds of feet wide) must make a DC 15 Dexterity saving throw. On a failed save they take 12 (4d6) bludgeoning damage and 12 (4d6) cold damage.

At this point, they are also buried in the snow and restrained. On a successful saving throw, they take half as much damage and are not restrained.

A restrained creature can try to free themselves, which requires a DC 20 Strength (Athletics) check and takes 5 (1d10) minutes.

Other creatures can try to help them, but they must find them first, which requires a DC 14 Intelligence (Investigation) or Wisdom (Perception) check.

Creatures trapped for 10 minutes or more, take 1 level of exhaustion. This level increases by 1 for every 3 hours that the creature is trapped.

Hellfire Geyser CR 8

Magical hazard

A geyser sprouts from the ground, showering the area in white-hot magma that pulses with black energy.

A geyser on the material plane is boiling steamy water that erupts from the ground which can cause damage to those nearby. Hellfire Geysers are similar, though they only occur naturally in the deepest levels of Hell. Sometimes they break through the barriers between the various planes of existence and erupt in the mortal realms, showering anyone found nearby with hellfire.

Detection A DC 15 Wisdom (Perception) or Intelligence (Arcana) check reveals the nature of the geyser and allows the hero making the check to notice the signs of a geyser eruption 3 (1d6) rounds before it occurs.

Effects When a Hellfire Geyser erupts it showers everyone with hellfire magma, which both burns and drains the life of those nearby.

Anyone within 30 feet must make a Dexterity saving throw. On a failed save, the target takes 33 (6d10) fire damage initially and then 11 (2d10) necrotic damage. This necrotic damage cannot be healed through normal means, and can only be healed after a lesser restoration or similar magic is cast upon the target. A creature who succeeds on the saving throw takes half as much fire damage and no necrotic damage.

The Hellfire Geyser then goes dormant for 3 (1d6) rounds, before it erupts again.

A Hellfire Geyser can be destroyed through the use of dispel evil (dismissal) or banishment (or similar magic). As an unliving object, it gets no saving throw against either spell but is a valid target for either spell.

Waters of the Styx CR 9

Magical Hazard

An ill-smelling sulfurous grey river, filled with detritus. Frequent bubbles surface on the grey, gooey surface, with each bubble looking like a screaming face just before it pops.

The River Styx crosses the planar boundaries between the Lower Planes, enabling a form of travel that does not rely solely on the use of magic. Fiends and their ilk frequently use it for their wars as well as for trade, while mortals tangle with the ferrymen of the Styx, hoping to cross the planes easily, but risking their souls in the process.

Occasionally, for unknown reasons, the river flows over and breaks through the borders to the Material Plane, temporarily replacing a normal river, before vanishing once more.

During this time, the ends of the river function like planar portals, and fiends sometimes use these portals to enter the mortal world.

A fiend using the river at the exact time it changes to the Material Plane is incredibly rare.

This is because these events are impossible to predict. Therefore, in most occurrences, the water is the main threat.

Detection A successful DC 8 Wisdom (Perception) check reveals that the normal river has been replaced by a foul-smelling otherworldly waterway. A DC 14 Intelligence (Arcana) check reveals that it has been replaced with the infamous Styx, and that creatures should avoid swimming in or breathing near it.

Effects Any creature other than a fiend that tastes or touches the water ·is affected by a feeblemind spell. The DC of the Intelligence saving throw to resist the effect is 15.

If the river replaces a waterfall, this gets more dangerous as the water vapor kicked up by the falling water is replaced with the muck of the River Styx. In that case, any living creature who is not a fiend, within 100 feet of the banks of the river must make the Intelligence saving throw to avoid being feebleminded.

Example Haunts

The other type of hazards, called haunts, includes those psychic impressions that might have otherwise led to the rise of undead creatures following a tragic event of some sort. Why these hauntings are created as opposed to the rise of an undead creature is unknown, but their effect can be just as devastating. Those experiencing a haunting report that they experience similar emotions as those that led to the haunting originally, but that is not always the case. Some of these haunts are simple emotional impacts, like experiencing a prolonged period of isolation and loneliness, but can also be more direct, like being possessed by the cannibalistic urges of an insane killer, perhaps on the site of their first murder.

When a living creature comes within 5 feet of a haunt, the creature experiences the haunt’s death sequence as a series of images flashing across its mind’s eye.

Detecting a haunt by normal means is difficult because it doesn’t have a physical form. Detect evil and good will reveal an aura of evil at the spot where a haunt has been imprinted. Destroying a haunt is equally challenging because it has no physical body to cause harm to. The first option is to cast hallow using the everlasting unrest variant of the spell, while the second option is to perform a ritual that banishes the haunt, as described in the individual haunt.

All haunts reform 24 hours after they are triggered, unless otherwise stated.

Ritual Destruction (only applies to haunts) All haunts can be destroyed through rituals tied in with the emotions felt when the haunt was created. A Wisdom (Insight) check reveals what form of ritual could please the restless spirit and end it.

Burned At The Stake CR 12

Haunt

Appearance A circular clearing in a field where a few embers and a charred wooden post remain as evidence of a large fire.

Trigger Approaching within 5 feet of the post.

Detection Detect evil reveals an aura of evil at the post.

On a successful DC 16 Wisdom (Perception) check you feel an unnatural sense of dread as though something especially horrific happened here.

Disarming or Destroying Casting hallow using the everlasting unrest option destroys the haunt. A successful DC 18 Intelligence (Religion) check reveals that sprinkling the site with 3 vials of holy water will destroy the haunt.

Damage and Effects The triggering creature sees a woman tied to a post engulfed in flames. The creature hears her screams, smells burning flesh, and feels the heat of the flames. The triggering creature must make a DC 17 Constitution saving throw. On a failed save, it takes 55 (10d10) fire damage and catches on fire. Any creature on fire takes 5 (1d10) fire damage at the start of its turn until it or an ally takes an action to douse the fire.

On a successful save, a creature takes half as much damage and does not catch on fire.

Ritual Destruction Destroying a Burned at the Stake haunt requires a DC 19 Wisdom (Insight) check to understand. To destroy the haunt, without the use of holy water, requires another person to be burned at the stake, but for it to work, the person burned must be convicted, and guilty, of arson that caused at least one person to die.

Dead Plains CR 6

Haunt

A deserted battlefield, with weapons and armor lying broken on and in the ground. The bones of long-dead warriors protrude alongside the weapons that killed them.

A battlefield is a powerful focus for emotions of all kinds. Anger at the enemy and the person who killed you. Sorrow at not being able to return to one’s family. Grief at seeing friends die, and rage at knowing one’s homeland could be invaded.

All of these emotions cause a battlefield to feel off-putting to many creatures, but some battlefields are harder hit than others — those that have seen the complete slaughter of one side. These are the areas that birth the Dead Plains.

Detection A DC 14 Wisdom (Perception) or Intelligence (Religion) check reveals that the battlefield is haunted by the effects of the combat that took place here.

Effects Any living creature who spends more than 10 minutes on the battlefield starts to see ghostly apparitions lining up for battle alongside them, and must make a DC 15 Wisdom saving throw.

A creature that succeeds on its saving throw can see through the apparitions and ignore them, though they still appear as ghostly creatures around them. A creature that fails its saving throw becomes convinced that they are a soldier on the losing side of a battle and finds themselves immersed within the echoes of the past that the Dead Plains impart of the longago battle. They take 21 (6d6) psychic damage and become frightened until they complete a long rest. These visions take 10 minutes before they stop and shaking a creature free from them (which can be done as an action by another creature) increases the psychic damage to 39 (6d12).

Ritual Destruction Destroying Dead Plains requires a DC 16 Wisdom (Insight) check to understand. The ritual requires a creature or person recognized as a commanding officer of one of the parties (or their spiritual successors) that took part in the battle to order the soldiers to stand down when experiencing the visions. All soldiers, regardless of allegiance, will then dissipate and the Dead Plains will be destroyed.

Heart of Ice CR 10

Haunt

A woman dressed in a bridal gown kneels on the ground, frozen in place by the arctic cold.

Some people feel their emotions and hearts turn to ice when they are abandoned at the altar, but very few make a pact with otherworldly forces following that, pledging themselves to darkness. When that happens, a Heart of Ice may form, infecting and killing those that come close.

Detection A DC 16 Wisdom (Perception) check reveals that the kneeling person isn’t real, in spite of appearing lifelike. The skin is made of ice, and the clothes of snow. When living creatures approach within 30 feet, they notice a creeping cold setting into their hearts.

Effects Any living creature that comes within 30 feet must make a DC 16 Constitution saving throw. A creature takes 27 (6d8) cold damage on a failed save, or half as much damage on a successful one. Furthermore, those that fail the saving throw are petrified (frozen solid). A petrified creature can repeat the saving throw at the end of each of its turns (taking damage each time), ending the effect on itself if it makes two successful saves. If a petrified creature gets two failures on the saving throw (not counting the original failure that caused the petrification), the petrification becomes permanent. A permanently petrified/frozen creature can be restored to normal with greater restoration or thawing them out by having them take damage from a wall of fire for two rounds. Discovering this fact requires a DC 17 Intelligence (Arcana) check.

Ritual Destruction Destroying a Heart of Ice requires a DC 18 Wisdom (Insight) check to understand. The ritual itself requires 2 living creatures, where one must declare their genuine love for the other, and have the other creature accept. If the emotions are not genuine or reciprocated, the ritual fails.

Section 15: Copyright Notice

enTRAPment - Traps and Hazards for 5e © 2022, Beyond the Horizon; Author: Kim Frandsen and Beth Jones.

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