Arcane Traps

Wizards and other practitioners of magic create traps that use spells as much as they use physical objects; some of these hindrances have features in common with pits and spear traps, while others rely on a series of finely wrought glyphs or enchanted components that require arcane knowledge to identify, much less disarm. A small collection of these traps is provided here.

Cthugha’s Caress

Magic trap (evocation)

The caress of Cthugha is patient, volatile, and the basis of a trap that evokers find appealing. When this trap is triggered by stepping on a pressure plate, opaque smoke fills a 10-foot square for 2 rounds atop the plate, leaving a thin film of soot on everything within the square when it dissipates. On the following round, a flame fills the same 10-foot square and lasts for 2 rounds, dealing 14 (4d6) fire damage, or half as much damage on a successful DC 14 Dexterity saving throw. Creatures covered in the soot have disadvantage on the saving throw.

A successful DC 14 Intelligence (Arcana) check identifies the soot as fire elemental residue. On a check that beats the DC by 4 or more, the character recalls that the substance is highly combustible. Removing the soot requires an action.

The pressure plate is detected with a successful DC 16 Wisdom (Perception) check, and it can be disarmed with a successful DC 14 Dexterity check using thieves’ tools.

Failing this check by 4 or more activates the trap.

Furies’ Moat

Magic trap (enchantment)

Wizards of northern tribes fight alongside their berserker brethren, intimately aware of the awful power, and strategic limitations, of a warrior in the thrall of mindless wrath. This trap is placed in a water-filled moat or ditch that is laced with enchantments to drive enemies into an incandescent, all-consuming rage.

The enchantment can be detected by a successful DC 14 Intelligence (Arcana) check. Swimming across the water to the other side of the moat without incident requires a successful DC 14 Strength (Athletics) check. On a failed check, the creature is swept under, taking 3 (1d6) cold damage, and it must make a successful DC 12 Wisdom saving throw or be filled with murderous anger that can be slaked only by attacking any creature within reach. While affected, a creature must use its action to attack the nearest other creature. An affected creature takes an additional 3 (1d6) cold damage at the end of its turn, and can repeat the saving throw, ending the effect on itself on a success.

Otherworldly Pipes

Magic trap (enchantment)

This auditory trap uses otherworldly piping to transform its listeners into addlepated imbeciles.

The trap’s insidious nature allows it to be hidden inside a chest, behind a tapestry, or even within a bell or among rafters. The only outward sign of the trap is a series of skewed star-like symbols engraved into the trapped room, chest, or object. The functional components (a series of small silver pipes, like a pan pipe, and a small set of magically animated bellows) can be found with a successful DC 12 Intelligence (Investigation) check. Once they are found, a successful DC 17 Intelligence (Arcana) check identifies the trap and the correct method of disarming it: a dispel magic spell (DC 17), which deactivates it for 1 hour. Attempts to physically disarm the trap by tampering with the pipes or bellows trigger its music and effects immediately.

Touching a trapped chest or object, or the door of a trapped room, triggers the trap. When this occurs, each creature within 10 feet takes 7 (2d6) psychic damage and must make a DC 12 Intelligence saving throw. On a failed save, the creature’s Intelligence and Charisma are decreased by 1d6 each. A creature takes the same psychic damage each round it listens to the piping; plugging one’s ears reduces the damage by half. The effect lasts until the creature finishes a long rest or is targeted by greater restoration or similar magic.

Infernal Convocation

Magic trap (conjuration)

An infernal convocation is a way to use a conjuration in a trap. A powerful caster binds a fiend, which is summoned to a specific site when a trigger occurs. The fiend collects a second sacrifice—whoever triggered the trap—and is freed of its debt to the caster.

The trap is triggered as soon as a creature enters a magic circle, which can be inscribed on the wall or ceiling, or even woven into a carpet or limned on a cavern floor. There’s no limit on the circle’s size; horrific tales of lairs being encircled are told over campfires.

The purpose of the circle is deduced with a successful DC 18 Intelligence (Arcana) check. It can be disarmed with a successful DC 15 Intelligence (Arcana) check or a dispel magic spell (which renders it briefly inactive). If a creature that is not proficient in Arcana gets a failure on either check, the trap is triggered and the fiend is summoned. An uncommon variant of the trap exists in which a wall of force spell traps both the prey and the summoned creature in the same area.

Seven Flavors (of Doom)

Magic trap (evocation)

The number seven holds mystical importance in many civilizations, but only kobolds apply that veneration to their beloved art of trapmaking. The creation known as seven flavors is a deceptively simple trap in which eldritch needles spring from seven hidden tubes to strike a single target and release their charge.

The trap is detected with a successful DC 15 Wisdom (Perception) check. It can be disarmed only with dispel magic, though it can be avoided or rendered ineffective by blocking all seven holes. Each needle makes a ranged attack with a +8 bonus. On a hit, a needle deals 7 (1d8+3) damage of a different type from this list: lightning, fire, cold, acid, psychic, thunder, or necrotic.

Step Softly

Magic trap (evocation/illusion)

The dwarven inventor of the trap known as step softly believed that adventurers are their own worst enemy, and couldn’t resist using their eagerness against them. A room is built with a false floor too flimsy to support any weight above a pit trap and temporarily braced with magic to give it additional strength.

When everyone in the party has entered the room, glyphs blaze into view, covering every inch of the floor, appearing to trap the occupants in their spots. A successful DC 10 Intelligence (Arcana) check reveals that the glyphs are used with evocation magic. A dispel magic spell dismisses the glyphs and the magic that supports the floor, causing everything on the false floor to fall into the pit beneath the room. A detect magic spell, coupled with a successful DC 18 Wisdom (Perception) check, reveals the glyphs glowing with illusion magic and a layer of evocation magic under them.

Dreamless Slumber

Magic trap (enchantment)

Sometimes capturing thieves is more important than permanently stopping them, and that was the impetus for creating the dreamless slumber trap, which layers an enchantment over a traditional needle trap on a chest or door. The trap is triggered by touching the chest or door.

When that occurs, the creature takes 1 piercing damage and must succeed on a DC 15 Wisdom saving throw or fall into a dreamless, ageless, magical stasis. The stasis remains until it is successfully removed by dispel magic (DC 17) or until three months have passed.

The trap can be detected with a successful DC 15 Intelligence (Investigation) check, and disarmed with a successful DC 15 Dexterity check using thieves’ tools.