Unearthed Arcana: Traps Revisited
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They aren’t officially part of the game and aren’t
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If we decide to make this material official, it will be
refined based on your feedback, and then it will appear
in a D&D book.

The rules for traps in the Dungeon Master’s Guide
provide the basic information you need to
manage traps at the game table. The material
here builds on the DMG rules and provides moreguidance on creating traps of your own.
Rather than focus on traps as mechanical or
magical, these rules separate traps into two
categories: simple traps and complex traps.

Simple Traps
A simple trap activates and is then harmless. A
hidden pit dug at the entrance of a goblin lair, apoison needle that pops from a lock, and acrossbow rigged to fire when an intruder steps
on a pressure plate are all simple traps.

Describing a Simple Trap
Simple traps require three elements to function:a trigger, an effect they have once triggered, andthe measures that can defeat them. In addition, a
trap is given a level and an overall description of
the threat it poses.
Level and Threat. A trap’s level is expressed
as a range of levels to give you an idea of its
relative strength (levels 1–4, 5–10, 11–16, and
17–20). It is then labeled as a moderate,
dangerous, or deadly threat. The trap’s label tells
you how powerful the trap is compared to othersof its level range.
Trigger. A simple trap has a trigger that
describes what causes the trap to activate. The
trigger’s description includes its location and theaction that causes it to activate.
Effect. A trap’s effect describes what happens
when its trigger activates. The trap might fire adart, unleash a cloud of poison gas, cause ahidden point to open, and so on. The effectspecifies who the trap targets, its attack bonus or©2017 Wizards of the Coast LLC

saving throw DC, and what happens on a hit or
failed saving throw.
Countermeasures. A trap can be defeated in avariety of ways. This section of a trap’s
description details the checks or spells that can
detect and disable it. It also specifies what
happens, if anything, on a failed attempt todisable it.

Running a Simple Trap
When managing a simple trap in play, start bymaking note of the characters’ passive
Perception scores. Most traps allow Wisdom(Perception) checks to detect their triggers orother elements that can tip off their presence. If
you stop to ask for checks, the players mightsuspect a hidden danger.
When a trap triggers, apply its effects as
specified in its description. Be sure of theplayers’ intended actions before a trap activatesso that it springs into action based on what theplayers want to do, rather than a course of action
they’re arguing about or merely considering.
If the players discover a trap, be open to
adjudicating their ideas for defeating it. The
trap’s description is a starting point for
countermeasures, rather than a complete
definition.
The players should be specific in how theywant to defeat the trap. Simply stating the desire
to make a check isn’t enough. Ask the players
where their characters are positioned and what
they intend to do to defeat the trap. A player
can’t just say, “I use thieves’ tools to disable it.”That’s too murky. The player instead should
describe something like, “I use my thieves’ tools
to examine the lock and attempt to disable thepoison needle inside it.” The last thing you wantis confusion over where the characters arelocated if a trap activates.
As a default, overcoming a simple trap offers
no experience point reward. If the characters
uncover the trap and avoid or disable it, theirreward is dodging a threatening element of thedungeon. If they stumble into it, they must copewith the consequences of a more dangerous
situation.

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Example Simple Traps
Here are examples of simple traps that you can
use to populate your adventures or as models foryour own creations.

Bear Trap
Simple trap (level 1–4, dangerous threat)
A bear trap resembles a set of iron jaws thatsprings shut when stepped on, clamping down
on a creature’s leg. The trap is spiked in the
ground, leaving the victim immobilized.
Trigger. A creature that steps on the bear trap
triggers it.
Effect. The trap makes an attack against thetriggering creature. The attack has a +8 attack
bonus and deals 5 (1d10) piercing damage on ahit. This attack can’t gain advantage ordisadvantage. A creature hit by the trap has its
speed reduced to 0. It can’t move until it breaks
free of the trap with a successful Strength check(DC 15) made by it or another creature adjacentto the trap.
Countermeasures. A DC 10 Wisdom(Perception) check reveals the trap. A DC 10
Dexterity check made with thieves’ tools
disables it.

Crossbow Trap
Simple trap (level 1–4, dangerous threat)
A crossbow trap is a favorite of kobolds andother creatures that rely on traps to defend theirlairs. It consists of a tripwire run across ahallway and connected to a pair of carefully
hidden heavy crossbows. The crossbows are
aimed to fire down the hallway at anyone who
triggers the tripwire.
Trigger. A creature that walks through thetripwire triggers the trap.
Effect. The trap makes two attacks against thetriggering creature. Each attack has a +8 attack
bonus and deals 5 (1d10) piercing damage on ahit. This attack can’t gain advantage ordisadvantage.
Countermeasures. A DC 15 Wisdom(Perception) check reveals the tripwire. A DC 15
Dexterity check made with thieves’ tools
disables the tripwire, but a check result of 5 orless triggers the trap.

©2017 Wizards of the Coast LLC

Falling Gate
Simple trap (level 1–4, deadly threat)
Some folk who build dungeons, such as madwizards in search of new victims, have nointention of allowing their visitors to make aneasy escape. This trap is fiendish because it
causes a gate to drop some distance away fromthe pressure plate. The gate might close off thedungeon entrance, which is hundreds of feetaway. Adventurers don’t know they are trapped
until they decide to head back to town.
Trigger. A creature that steps on the pressure
plate triggers this trap.
Effect. The trap causes an iron gate to dropfrom the ceiling, blocking the exit from the maze.
Countermeasures. A DC 20 Wisdom(Perception) check reveals the pressure plate. A
DC 20 Dexterity check made with thieves’ tools
disables it, but a check result of 5 or less triggers
the trap.

Fiery Blast
Simple trap (level 5–10, dangerous threat)
The temple of Pyremius, a god of fire, is plaguedby thieves who seek to steal the fire opals
collected by the priests in tribute to their god. A
mosaic on the floor of the entryway to the inner
sanctum delivers a fiery rebuke to intruders.
Trigger. Anyone stepping on the mosaic
causes fire to erupt from it. Those openly
wearing holy symbols of Pyremius don’t trigger
this trap.
Effect. A 15-foot cone of fire erupts, covering
the pressure plate and the area around it. Eachcreature in the cone must make a DC 15
Dexterity saving throw, taking 24 (7d6) firedamage on a failed save, or half as much damage
on a successful one.
Countermeasures. A DC 15 Intelligence(Investigation) check reveals ash and faint burnmarks in the shape of the fiery cone created bythis trap. A DC 15 Intelligence (Religion) checkallows a creature to destroy the trap by defacinga key rune in the mosaic; failing this checkcauses the trap to activate. A successful dispel
magic (DC 15) cast on the runes destroys the
trap.

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Net Trap
Simple trap (level 1–4, dangerous threat)
Goblins, with their propensity to enslave theirenemies, prefer traps that leave intruders intact
for work in the goblins’ mines or elsewhere.
Trigger. A tripwire strung across a hallway isrigged to a large net. If the tripwire is broken, thenet falls on intruders. An iron bell is also rigged
to the tripwire. It rings when the trap activates,
alerting nearby guards.
Effect. A net covering a 10-foot-by-10-footarea centered on the tripwire falls to the floor asa bell rings. Any creature fully within this area
must succeed on a DC 15 Dexterity saving throwor be restrained. A creature can use its action to
make a DC 10 Strength check to try to free itself
or another creature in the net. Dealing 5 slashingdamage to the net (AC 10) also frees a creature
without harming the creature.
Countermeasures. A DC 15 Wisdom(Perception) check reveals the tripwire and thenet. A DC 15 Dexterity check made with thieves’tools disables the tripwire without dropping thenet or ringing the bell; failing the check causes
the trap to activate.

Pit Trap
Simple trap (level 1–4, moderate threat)
This trap consists of a 10-foot deep pit,
concealed by a tattered canvass covered withleaves and dirt. This type of trap is useful forblocking off the entrance to a monster lair andusually has narrow, safe ledges along its sides.
Trigger. Anyone stepping on the canvassmight fall into the pit.
Effect. The triggering creature must make a DC
10 Dexterity saving throw. On a successful save,the creature catches on the pit’s edge or
instinctively steps back. Otherwise, the creature
falls into the pit and takes 3 (1d6) bludgeoning
damage from the fall.
Countermeasures. A DC 10 Wisdom(Perception) check reveals the canvass. A 1-footwide ledge around the edge of the pit is safe to
cross.

Poison Needle
Simple trap (level 1–4, deadly threat)
A tiny, poisoned needle hidden in a lock is theperfect way to discourage thieves fromplundering a hoard. Such a trap is usually put ina chest or in the door to a treasure chamber.
©2017 Wizards of the Coast LLC

Trigger. Anyone attempting to pick or open
the lock triggers the trap.
Effect. The triggering creature must make a DC
20 Constitution saving throw. On a failed save,the creature takes 14 (4d6) poison damage andis poisoned for 10 minutes. While poisoned inthis way, the creature is paralyzed. On a
successful save, the creature takes half as muchdamage and isn’t poisoned.
Countermeasures. A DC 20 Wisdom(Perception) check reveals the needle, but only if
a character inspects the lock. A DC 20 Dexterity
check made with thieves’ tools disables theneedle, but a check result of 10 or less triggers
the trap.

Scything Blade
Simple trap (level 5–10, dangerous threat)
These deadly blades sweep down through achamber. A wooden lever activates this trap
when it is pulled. Kobolds particularly love thisstyle of trap, as it puts bigger creatures indanger.
Trigger. When the lever is pulled, the trap
activates.
Effect. Each Medium or larger creature in a 5foot-wide and 20-foot-long area must make a DC
15 Dexterity saving throw, taking 14 (4d6)slashing damage on a failed save, or half as muchdamage on a successful one.
Countermeasures. The lever isn’t hidden. A
DC 15 Intelligence (Investigation) check reveals
scrape marks and blood stains in the trap’s areaof effect. A DC 15 Dexterity check made withthieves’ tools disables the lever.

Sleep of Ages
Simple trap (level 11–16, deadly threat)
A pressure plate unleashes a spell that threatens
to send intruders into a deep slumber. The
dungeon’s guardians can then dispose of thesleepers.
Trigger. Stepping on the pressure plate
triggers this trap.
Effect. When activated, this trap casts a sleep
spell centered on the pressure plate using a 9thlevel spell slot.
Countermeasures. A DC 20 Wisdom(Perception) check reveals the pressure plate. A
DC 20 Intelligence (Arcana) check made within 5feet of the pressure plate disables the trap, but acheck result of 10 or less triggers it. A successful3dispel magic (DC 19) cast on the pressure plate
destroys the trap.

Designing Simple Traps
You can create a simple trap by using thefollowing guidelines. You can also adapt theexample traps by modifying DCs and damage
values, based on the target level and threat for
the trap.

PurposeBefore diving into the details of your trap, think
about its purpose. Why would someone build
this trap? What is its purpose? Think of the
trap’s creator, the creator’s purpose, and thelocation that the trap protects. Traps havecontext in the world, and that context drives the
trap’s nature and effects.
Described below are a few of the purposes a
trap might have. Use them to inspire the creationof your own traps.
Alarm. An alarm trap is designed to alert anarea’s occupants of intruders. It might cause abell or gong to sound. This type of trap rarely
involves a saving throw.
Delay. These traps serve to slow down
intruders, giving a dungeon’s inhabitants time tomount a defense or flee. A hidden pit is theclassic example of this trap. A 10-foot-deep pit
usually deals little damage and is easy to escape,but it slows down intruders. Other examples
include collapsing walls, a portcullis that drops
from the ceiling, and a locking mechanism thatshuts and bars a door. These traps, when they
directly threaten characters, usually require a
Dexterity saving throw to avoid.
Restrain. A restraining trap tries to keep its
victims in place, leaving them unable to move.
These traps are most useful when combinedwith a regular guard patrol, but in ancient
dungeons the guards might be long gone. These
traps usually require a Strength saving throw to
avoid, but some don’t allow saves. In addition to
dealing damage, they also render a creatureunable to move. A subsequent, successful
Strength check (use the saving throw DC) or
damage against the trap can break it and free thecaptive. Examples include a bear trap, a cage thatdrops from a ceiling, or a device that flings a net.
Slay. These traps are designed to eliminate
intruders. They include poisoned needles thatspring out when a lock is tampered with, blasts©2017 Wizards of the Coast LLC

of fire that fill a room, poison gas, and so on.
Saving throws—usually Dexterity or
Constitution—allow creatures to avoid or
mitigate the trap’s effects.

Level and Lethality
Before creating a trap’s effects, think about its
level and its lethality.
Traps are divided into four level ranges, 1st–
4th, 5th–10th, 11th–16th, and 17th–20th. A
trap’s level range gives you a starting point for
its potency.
To further calibrate the trap’s strength, pickwhether it is a moderate, dangerous, or deadly
threat within its level range. A moderate trap isunlikely to kill a character and is the weakest
trap type. Dangerous traps deal enough damage
that a character hit by one is eager for healing. A
deadly trap might reduce a creature to 0 hit
points in one shot, and leaves most creatures inneed of a short or long rest.
Consult the following tables when nailing
down a trap’s effects. The Trap Save DCs andAttack Bonuses table provides guidelines for a
trap’s save DC, check DC, and attack bonus. The
check DC is the default number used for any
check used to interact with the trap.
The Damage Severity by Level table lists the
typical damage a trap deals at certain character
levels. The damage listed assumes the trap
damages one creature. Use d6s for damage inplace of d10s for traps that can affect more than
one character at a time.
The Spell Equivalent by Level lists the spell
slot level that is appropriate for the given
character level and the danger posed by the trap.
A spell is a great shortcut to use when designinga trap, whether the trap duplicates the spell (amirror that throws charm person on whoever
looks into it) or uses its effects (an alchemical
device that explodes like fireball). Note that the
Deadly entry for characters above 17th level
suggests combining a 9th and 5th level spell into
one effect. In this case, pick two spells, or
combine the effects of a spell cast using a 9thlevel and a 5th-level slot.

Trap Save DCs and Attack Bonuses
Trap Danger
Moderate
Dangerous
DeadlySave/Check DC
10
15
20

Attack Bonus
+5
+8
+12

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Damage Severity by Level
CharacterLevel
1st–4th5th–10th
11th–16th
17th–20thModerate
5 (1d10)11 (2d10)
22 (4d10)55 (10d10)Dangerous
11 (2d10)
22 (4d10)55 (10d10)
99 (18d10)

Deadly22 (4d10)55 (10d10)
99 (18d10)
132 (24d10)

Spell Equivalent by Level
CharacterLevel
1st–4th5th–10th
11th–16th
17th–20thModerate
Cantrip
1st
3rd
6th

Dangerous
1st
3rd
6th
9th

Deadly2nd
6th
9th
9th + 5th

Triggers
A trigger is the circumstance that needs to takeplace to activate the trap.
Decide what causes the trap to activate anddetermine how the characters can find thetrigger. Here are some example triggers:• a pressure plate that, when stepped on,
activates the trap
• a tripwire that springs a trap when it isbroken, usually when someone walks throughit• a doorknob that activates a trap when it isturned the wrong way• a door or chest that triggers a trap when it isopenedA trigger usually needs to be hidden to beeffective. Otherwise, avoiding the trap is triviallyeasy.
A trigger requires a Wisdom (Perception)
check if simply spotting it reveals its nature. The
characters can foil a pit trap hidden by a leafcovered net if they spot the pit through a gap in
the leaves. A tripwire is foiled if spotted, as is apressure plate.
Other traps require careful inspection anddeduction to notice. A doorknob opens a door
when turned to the left, but activates a trap
when turned to the right. Such a subtle trap
requires a successful Intelligence (Investigation)
check to notice. The trigger is obvious.
Understanding its nature is not.
The DC of the check, regardless of its type,
depends on the skill and care taken to conceal
the trap. Most traps require a DC 20 check tospot, but a poorly made or hastily built trap has a©2017 Wizards of the Coast LLC

DC of 15. Exceptionally devious pitfalls might
have a DC of 25.
You must then put some thought into whatcharacters learn with a successful check. In mostcases, the check reveals the trap. In other cases,
it uncovers useful clues but still requires somededuction. The characters might succeed on the
check but still trigger the trap if they fail tounderstand what they have learned.

Perception and Investigation
A Wisdom (Perception) check that reveals a tripwire
doesn’t tell the players what happens if they break the
tripwire. They spot it before blundering into it, but muststill decide what to do next. The nature of the item is
not in question, but you might not spot it. A successfulcheck reveals it.
An Intelligence (Investigation) check reveals that the
scuff marks and wear pattern show that a doorknob canturn both ways, but is most often turned clockwise. The
players must still decide how to open the door. The item
is obvious, but its true nature is obscured. A successfulcheck reveals the clues that point to the item’s purpose.

Effects
Designing a trap’s effects is a straightforward
process. The tables for save DCs, attack bonuses,
damage, and the like give you a starting point formost simple traps that deal damage.
For traps with more complex effects, your best
starting point is to use the Spell Equivalent by
Level table to find the best match for your trap’s
intended effect. Spells are a good starting point
because they are compact pieces of game designthat deliver specific effects.
Once you have chosen the effect the trap
delivers, choose its damage, attack bonus, andsave DC. If you are using a spell as a starting
point, check to see if you need to tweak its
effects to fit the trap’s nature. For instance, you
can easily change the damage type a spelldelivers or the saving throw it requires.

Disarming Simple Traps
Simple traps require a single ability check todisarm. Imagine how the trap operates, and thenthink about how the characters can overcome it.
Not all traps can be disarmed in a traditional
way. A hidden pit trap is effectively disarmed
when the characters notice it. The characters can
simply walk around it or climb down one side,
walk across it, and climb up the other side.
Once you determine how a trap can bedisarmed, pick the appropriate ability and skill
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combinations that characters can use. In mostcases, a Dexterity check made with thieves’ tools,
a Strength (Athletics) check, or an Intelligence(Arcana) check can overcome a trap.
A Dexterity check made with thieves’ tools canapply to any trap with a mechanical element.
Thieves’ tools can be used to safely disable a
tripwire or pressure plate, disassemble a poison
needle mechanism, or stop up a valve that leaks
poisonous gas into a room.
Strength checks are useful for traps that can be
destroyed or held back through brute force. A
scything blade can be broken, a collapsing roof
held in place, a net torn apart.
Magical traps can be disabled by someone who
can undermine the magic used to power them.
An Intelligence (Arcana) check allows acharacter to figure out how the trap functions
and how to disable its magic. A statue thatbelches a jet of magical flame might be disabled
when one of its glass eyes is shattered,disrupting the magic that powers it.
Finally, decide if there are any drawbacks to afailed attempt to disable the trap. If so, pick a
threshold for the check result or decide that any
failure activates the trap. If the result hits thatthreshold or lower, the trap activates. This
option is a useful tool to make a trap feel
dangerous even if the characters havediscovered it. A trap that can be disabled without
any danger is like a monster that can’t fight back.
Of course, use logic to guide your decisions. Thiselement makes a trap interesting, but itshouldn’t come at the cost of making your gamefeel illogical or arbitrary. For instance, let’s say
your trap is a section of floor that opens to sendcharacters tumbling into a pit. If the rogue
attempting to disarm the pit stands next to thetrap, it makes no sense for the rogue to fall in if
the trap activates. Of course, you can remedy thisby specifying that the character must lean over
the trap or have one foot on it to reach anddisable the mechanism.

Placing Simple Traps
Context is everything with traps. A log trap thatknocks characters aside is an inconvenience on
the typical forest path. It’s a potentially deadly
hazard on a narrow trail that hugs the side of a
towering cliff face.
Chokepoints and narrow passages that lead toimportant places in a dungeon are a good spot
for traps, especially those traps that serve as
alarms or restraints. These traps foil intruders©2017 Wizards of the Coast LLC

before they can reach a critical location, giving
the dungeon’s denizens a chance to mount adefense.
Treasure chests, doors to vaults, and any otherbarrier or container that holds a valuable
treasure is the ideal location for a slaying trap. In
this case, the trap is the final line of defense thatcan eliminate a thief or intruder.
Alarm traps, since they pose no direct physicalthreat, are ideal for areas that are used by adungeon’s denizens. If a stumbling goblin
activates an alarm trap, there’s no real harmdone. The alarm sounds, the guards arrive, they
berate the clumsy goblin, and then they reset the
trap. Of course, an alarm trap that is triggered on
accident too often might fail to generate a quick
response from defenders.
Above all else, place traps logically and withconsideration to the time and effort needed tomake them. If your adventures are sown withtoo many traps, the game grinds to a halt as theplayers search every square inch of a dungeon
for tripwires and pressure plates.
It’s all right if the players correctly deduce a
trap’s presence. That means your trap wasplaced logically and the players are engaged withthe game.

Complex Traps
A complex trap poses multiple dangers toadventurers. Once a complex trap activates, itremains dangerous round after round until thecharacters avoid it or disable it. Some complex
traps grow more dangerous over time, as theygather power or gain speed.
Complex traps are also more difficult todisable than simple ones. A single check is notenough to disable one. Instead, a series of checks
is required to slowly disable each component.
The trap degrades with each check until thecharacters finally deactivate it.
Most complex traps are designed so that they
can be disarmed only if you are willing to risk
the trap’s effects. For example, in a hallway filledwith scything blades, the mechanism that
controls them is on the opposite end from theentrance, or a statue that bathes an area innecrotic energy can only be disabled while
standing in the zone of energy it emits.

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Describing a Complex Trap
Complex traps build on the four parts of a simple
trap, adding in elements that make the trap amore dynamic threat.
Level and Threat. A complex trap uses thesame level bands and ratings for its lethality as asimple trap does.
Trigger. Just like a simple trap, a complex one
has a trigger. Some complex traps have multiple
triggers.
Initiative. A complex trap takes turns like acreature does. Complex traps are slow (initiative10), fast (initiative 20), or very fast (initiative 20
and 10).
Active Elements. On a trap’s turn, it activatesspecific effects that are detailed in its
description. The trap might have multiple active
elements, a table you roll on to determine its
effect at random, or options for you to choosefrom.
Dynamic Elements. Many complex traps
feature a changing threat. The trap’s description
tells you how the trap changes over time.
Usually, these changes take effect at the end ofeach of its turns or in response to the characters’
actions.
Constant Elements. A complex trap poses athreat even when it is not its turn. The constantelements describe how these parts of the trap
function. Most make an attack or force a saving
throw against creatures that end their turns
within certain areas.
Countermeasures. A trap can be defeated in avariety of ways. A trap’s description details thechecks or spells that can detect and disable it. It
also specifies what happens, if anything, on afailed attempt to disable it.
Disabling a complex trap is like disarming asimple trap, except that a complex trap requires
more checks. It typically takes three successfulchecks to disable one of a complex trap’s
elements. Many of these traps have multiple
elements, requiring a lot of work to shut down
every part of the trap. Usually, a successful check
reduces a trap element’s effectiveness if it
doesn’t disable it.

Running a Complex Trap

acted, the trap’s features activate. Apply theeffects detailed in the trap’s description.
After resolving the effects of the trap’s active
elements, check its dynamic elements to see ifanything changes about the trap. Many complex
traps have effects that vary over the course of an
encounter. A magical aura might do moredamage the longer it is active, or a swinging
blade might shift which area of a chamber it
attacks.
The trap’s constant elements allow it to haveeffects when it isn’t the trap’s turn. At the end ofeach creature’s turn, look at the trap’s constantelements to see if any of its effects trigger.

Example Complex Traps
Here are examples of complex traps to inspire
your own creations.

Path of BladesComplex trap (level 1–4, dangerous threat)
Hidden within a buried pyramid that marks thelocation of the Lost City of Cynidicea is the tombof King Alexander and Queen Zenobia. The
entrance to their tomb is a long hallway riddledwith traps, accessible only by cunningly hidden
secret doors. The hallway is 20 feet wide and
160 feet long. It is mostly clear. After 80 feet, thefloor is broken and cracked and is difficult
terrain until the 130-foot mark.
Trigger. This trap activates as soon as a nonundead creature enters the hallway, and it
remains active while any non-undead creature is
within it.
Initiative. The trap acts on initiative 20 and
10.
Active Elements. The Path of Blades includes aset of whirling blades along the first 80 feet of
the trap, crushing pillars that slam down fromthe ceiling to the floor before rising back up to
the ceiling in the next 50 feet, and a rune of fearin its final 30 feet.
Whirling Blades (Initiative 20). The blades
attack each creature in the first 80 feet of thehallway, with a +5 bonus to the attack roll anddealing 11 (2d10) slashing damage on a hit.

A complex trap functions in play like a legendary
monster. When activated, the trap’s active
elements act on either initiative 20 or 10 (orboth, for very fast traps). On that initiative count,after all creatures with that same initiative have©2017 Wizards of the Coast LLC

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Crushing Pillars (Initiative 10). Each creature
81–130 feet down the hallway must make a DC
15 Dexterity saving throw, taking 11 (2d10)
bludgeoning damage and being knocked prone
on a failed save, or half as much damage on a
successful one.
Rune of Fear (Initiative 10). Each creature in
the final 30 feet of the corridor must make a
DC 15 Wisdom saving throw. On a failed saving
throw, the creature is frightened of the rune,
and the creature must immediately use its
reaction to move its speed away from the endof the corridor. The frightened creature can’t
move closer to the end of the hallway until it
uses an action to succeed on a DC 15 Wisdomsaving throw, which ends the frightened
condition on itself.

Intelligence (Investigation), DC 15. This checkreveals the blade’s pattern. As an action, acreature that can see the blades can attempt
this check. Success imposes disadvantage on
the blades’ attacks against the creature while
it isn’t incapacitated.
Attack. A creature in the area can ready an
attack to slash at a blade. The blade gains
advantage on its attack against the creature.
The creature then attacks. The blades haveAC 15 and 15 hit points. Destroying a blade
reduces its attack bonus by 2.
Dexterity check with thieves’ tools, DC 15.
Creatures can use thieves’ tools in the area
attacked by the blades to foil theirmechanism. A successful check reduces theblades’ attack bonus by 2.

Dynamic Element—Blades Miss. The blades
move with increasing speed, slowing only when
they hit a target. Each time the blades miss withan attack, increase their damage by 3 (1d6) andtheir attack bonus by +2. These benefits last until
the blades hit a target.
Dynamic Element—Rune’s Defense.
Tampering with the rune of fear to disable it
increases the trap’s power. Each successfulcheck increases the damage of the blades andcrushing pillars by 5 (1d10) and increases therune’s save DC by 1.
Constant Elements. The whirling blades andthe rune of fear affect creatures that end theirturns in the elements’ areas

Crushing Pillars. The pillars have no effective
countermeasure.
Rune of Fear. The rune can be disabled withthree successful DC 15 Intelligence (Arcana)checks to disrupt the rune. Each checkrequires an action. A creature must be at theend of the hallway to attempt the check, andonly one creature can work on this task at
once. Once a creature attempts a check, noother character can make the same check until
the end of that creature’s next turn.
Alternatively, the rune can be disabled withthree successful castings of dispel magic (DC13) targeting the rune.

Whirling Blades. Any creature ending its turn inthe blade’s area is targeted by an attack: +5 tohit; 5 (1d10) slashing damage on a hit.
Rune of Fear. Any creature ending its turnwithin 30 feet of the far end of the corridor
must make a saving throw against the rune offear effect.
Countermeasures. Each of the trap’s active
elements offers potential countermeasures.
Whirling Blades. Characters can smash theblades, damage their components, or study
their pattern to avoid them; the blades are
disabled if their total attack bonus fromattacks and attempts to disable them reaches−8:©2017 Wizards of the Coast LLC

Sphere of Crushing DoomComplex trap (level 5–10, deadly threat)
The court jester devised a deadly trap to foil
anyone who sought to steal his magical fool’scap. The jester’s tomb is located at the end of a
10-foot wide, 150-foot long hallway that runs
north–south with a sharp slope down. The
entrance to the tomb is a door at the bottom of
the slope at the southern end of the hall. A dooron the eastern wall allows access to the tomb.
Trigger. This trap activates as soon as the lid
to the jester’s coffin is opened. A magical portal
opens at the northern end of the hallway anddisgorges a giant, steel sphere, which hurtles
down the slope. When it reaches the bottom of
the slope, a second portal briefly appears andteleports the sphere back to the top of the slope
to begin the process again.
Initiative. The trap acts on initiative 10 (butsee the dynamic element below).

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Active Elements—Sphere of Crushing Doom(Initiative 10). The Sphere of Crushing Doom isa spherical boulder that almost fills the hallway.
Each creature in the hallway must make a DC 20
Strength saving throw when the sphereactivates. On a failed save, a creature takes 22(4d10) bludgeoning damage and is knocked
prone. On a successful save, a creature takes half
as much damage and isn’t knocked prone.
Objects that block the sphere, such as a conjured
wall, take maximum damage from the impact.
Dynamic Element—Speed Kills. After its turn,the boulder gains speed, represented by its
damage increasing by 11 (2d10). While its
damage is 55 (10d10) or greater, it acts on both
initiative 20 and 10.
Countermeasures. There are a few ways thatthe trap can be disarmed.
Stop the Sphere. Stopping the sphere is theeasiest way to disrupt the trap. A wall of force
can stop it easily, and any object that hasenough hit points to absorb damage from thesphere without being destroyed can stop it.
Disrupt the Portals. Either portal can be
neutralized with three successful DC 20
Intelligence (Arcana) checks, but the processof analyzing a portal to disrupt it takes time.
Faint runes in the ceiling and floor on bothends of the hallway open the portals. A
creature must first use an action to examine a
set of runes, then use a subsequent action toattempt to vandalize them. Each successfulcheck reduces the sphere’s damage by 11(2d10), as the disrupted sphere loses speed
moving through the failing gate.
Alternatively, a set of runes can be disabledwith three successful castings of dispel magic(DC 19) targeting any of the runes in the set.
If the southern portal is destroyed, thesphere slams into the wall and comes to a halt.
It blocks the door to the tomb, but characters
can escape.

Poisoned Tempest
Complex trap (level 11–16, deadly threat)
This fiendish trap was built to eliminate
intruders who infiltrate a yuan-ti temple. The
trap is a room, 60-foot square with 5-foot-widestone doors in the middle of each wall. In eachcorner of the room stands a 10-foot-tall statue ofa great serpent, coiled and ready to strike. Theeyes in each statue are rubies worth 200 gp
apiece.
©2017 Wizards of the Coast LLC

Trigger. This trap activates when a ruby ispried from one of the statues. Each statue’s
mouth slides open, revealing a 1-foot-wide piperunning down its throat.
Initiative. The trap acts on initiative 20 and 10(but see the dynamic element below).
Active Elements. The Poisoned Tempest fills
the room with poison and other deadly effects.
Locked Doors (Initiative 20). The four doors tothis room slam shut and are locked in place bymagic. This effect activates once, the first time
the trap activates.
Poison Gas (Initiative 20). Poison gas floods
the room. Each creature inside must make a
DC 20 Constitution saving throw, taking 33(6d10) poison damage on a failed save, or half
as much damage on a successful one.
Tempest (Initiative 10). A mixture of air andgas boils up from the trap. Roll a d6 andconsult the Tempest Effects table.

Tempest Effects
d6
1

2

3

4

5

6

EffectHallucinatory gas scrambles the mind andsenses. All Intelligence and Wisdom checks
made in the room suffer disadvantage until the
Tempest element activates again.
Explosive gas fills the area. If anyone holds anopen flame, it explodes and deals 22 (4d10)
fire damage to everyone in the room (DC 20
Dexterity save for half damage). The open
flames are then extinguished.
Weakening gas fills the room. All Strength andDexterity checks made in the room suffer
disadvantage until the Tempest element
activates again.
Buffeting winds force everyone in the room tosucceed on a DC 20 Strength saving throw or
be knocked prone.
Smoke fills the room. Visibility is reduced to 1
foot until the next time the Tempest element
activates.
Additional poison floods the room, as in the
Poison Gas element.

Dynamic Element—Increased Potency. The
damage from the Poison Gas element increases
by 11 (2d10) after it activates, to a maximum of
55 (10d10).
Countermeasures. There are a few ways thatthe trap can be overcome.

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Open the Doors. Opening the doors is thequickest way to escape the trap, but they arewarded with magic. To open the doors, thecharacters must first make a DC 20 Wisdom(Perception) check to find the locking
mechanism. A DC 20 Intelligence (Arcana)check disables the sphere of force thatsurrounds the lock (dispel magic is ineffective
against it). Finally, a DC 20 Dexterity checkmade with thieves’ tools picks the lock. Finally,a DC 20 Strength (Athletics) check is needed topush the door open. Each check requires anaction.
Disable the Statues. A statue can be disabled byblocking the flow of gas from its mouth.
Destroying the statue is a bad idea, for it leaves
the gas vents open. A DC 20 Strength check or
an attack that deals more than 20 damage to astatue cracks it and increases the Poison Gas
damage by 5 (1d10). A successful DC 20
Dexterity check with thieves’ tools, or a DC 15
Strength check made to block up the statuewith a cloak or similar object, decreases the
poison damage by 5 (1d10). Once a character
succeeds at the check, someone must remain
next to the statue to keep it blocked up. Once
all four statues are blocked in this manner, thetrap deactivates.

Designing Complex Traps
Creating a complex trap takes more work thanbuilding a simple one, but with some practice
you can learn the process and make it movequickly.
Familiarize yourself with the guidelines ondesigning a simple trap before proceeding withthese guidelines on complex ones.

PurposeComplex traps are typically designed to protect
an area by killing or disabling intruders. It is
worth your time to consider who made the trap,
the trap’s purpose, and its desired result. Does
the trap protect a treasure? Does it target only
certain intruders? Use the advice given forsimple traps as a starting point.

Level and Lethality
Complex traps use the same level bands andlethality ratings as simple traps. Refer back tothat section for a discussion of how level andlethality help determine save and check DCs,

©2017 Wizards of the Coast LLC

attacks bonuses, and other numerical elementsof a complex trap.

Map
A complex trap has multiple parts, typicallyrelies on the characters’ positions to resolve
some of its effects, and can bring several effects
to bear each round. The traps are called complex
for a reason! To make design easier, draw a mapof the area affected by the trap using 5 feet foreach square on your graph paper. This level ofdetail allows you to develop a clear idea of what
the trap can do and how each of its parts
interact. Your map is the starting point andcontext for the rest of the trap-design process.
Don’t limit yourself to one room. Look at thepassages and rooms around the area of the trap
and think about the role they can play. The trap
might cause doors to lock and gates to fall into
place to prevent escape. It could cause darts tofire from the walls in one area, forcing charactersto enter rooms where other devices trigger andthreaten them.
Consider how terrain and furniture can add tothe trap’s danger. A chasm or pit might create
the distance that allows a trap to send bolts ofmagic at the characters while making it difficult
or even impossible to reach the runes the party
must deface to foil it.
Think of your map like a script. Where do thecharacters want to go? What does the trap
protect? How can the characters get there? What
are their likely escape routes? Answering thosequestions tells you where the trap’s various
elements should be placed.

Active Elements
A complex trap’s active elements work the same
way as a simple trap’s effects, except that acomplex trap activates every round. Otherwise,
the guidelines for picking save DCs, attack
bonuses, and damage are the same. To makeyour trap logically consistent, make sure theelements you design can activate each round. For
instance, crossbows rigged to fire at thecharacters need a mechanism to reload them.
In terms of lethality, it’s better to have multiple
dangerous effects in a trap than a single deadly
one. As a rule of thumb, build your trap with two
dangerous trap elements and one moderate one.
It’s useful to create multiple active elements,
each affecting a different area covered by the
trap. It is also a good idea to use a variety of10

effects. Some parts of the trap might cause
damage, and others might immobilize characters
or isolate them from the rest of the party. Think
about how the elements can work together. A
bashing lever might knock characters into thearea engulfed by jets of flame.

Constant Elements
In addition to the active steps a complex trap
takes, it should also present a continual hazard.
Often, the active and constant effects are thesame thing. Imagine a hallway filled withwhirling saw blades. On the trap’s turn, theblades attack anyone in the hall. In addition,anyone who lingers in the hallway takes damage
at the end of each of their turns, representing theconstant threat the blades pose.
A constant element should apply its effect toany character who ends their turn in thatelement’s area. If an active element presents a
threat when it isn’t its turn, determine the threat
it poses as a constant element. As a rule ofthumb, keep the saving throw DC or attack
bonus the same but reduce the damage by half.
Avoid filling the entire encounter area withconstant elements. Part of the puzzle of acomplex trap lies in figuring out which areas aresafe. A moment’s respite can help add anelement of pacing to a complex trap and give thecharacters the feeling that they aren’t in constantperil. For example, walls that slam together
might need to reset between slams, leaving themharmless when it isn’t their turn.

Dynamic Elements
Just as a battle is more interesting if themonsters change their tactics or unveil new
abilities in later rounds, so too are complex traps
more fun if their nature changes in some way.
The whirling blades that protect a treasure chest
do more damage each round, as they speed up.
The poison gas in a room grows thicker as moreof it floods the chamber, dealing more damage
and blocking line of sight. The necrotic aura
around an idol of Demogorgon produces random
effects each time it triggers its active effect. As
water floods a chamber, the characters mustswim across areas they could walk through just around or two before.
Since complex traps remain active over thecourse of several rounds, they can pose an
ongoing threat to intruders. However, if thatthreat becomes predictable its victims have a©2017 Wizards of the Coast LLC

much better chance of thwarting it. Complex
traps work best when they present multiple
threats to intruders, ones that can change eachround. The changes can include how a trap
targets the characters (attack or even type ofsaving throw), the damage or effects it deals, theareas it covers, and so on. Some traps might havea random effect each round, while others follow
a carefully programmed sequence of attacks
designed to frustrate and slay intruders.
Dynamic elements can occur on schedule. Fora room that floods, you can plan out how therising water level affects the area each round.
The water might be ankle deep at the end of thefirst round, knee deep the next, and so on. Not
only does the water carry a drowning risk, but it
also makes it harder to move across the area;
however, the rising water level might allow
characters to swim to the upper reaches of thechamber that they couldn’t reach from the floor.
Dynamic elements can also come into play inreaction to the characters’ actions. Disarming
one element of the trap might make the others
deadlier. Disabling a rune that triggers a firebreathing statue might cause the statue toexplode, as the magic in it runs rampant. If acreature dies in the room, the idol to the god
Nerull drains its soul and gains a new power.
A trap’s dynamic elements also make for agood timer. For example, the damage dealt bypoison gas in a room starts at 11, but doubles
each time the trap takes its turn. Smart players
see that they only have a few rounds toovercome the trap before they must flee or risk
death.
Random dynamic elements are fun because
they keep the players on their toes and make any
plan made to foil it dependent on the luck of thedice. In this case, you create a table and roll on it
to see how the trap changes. The players cannever be sure what might happen next. As a ruleof thumb, one random element for a complex
trap is a good limit. A trap that is too random canfeel arbitrary and frustrating. You want to makeplanning harder, not impossible.
The dynamic elements should change after the
trap’s turn. The water level rises after the trap’s
active element takes its turn. The blades speed
up and deal an additional die of damage eachtime they miss a character, their damage
returning to its starting point after the impact ofa successful attack causes them to slow down.

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Triggers
The advice on triggers given for simple traps
applies to complex ones, with one exception.
Complex traps feature multiple triggers, or aredesigned such that avoiding a trigger prevents
intruders from reaching the area the trap guards.
Other complex traps use magical triggers that
activate on specific cues, such as when a door
opens or someone enters an area withoutwearing the correct badge, amulet, or robe.
Look at your map and consider when you want
the trap to spring into action. It’s best to have acomplex trap trigger after the characters havecommitted to exploring an area. A simple trap
might trigger when the characters open a door. A
complex one that triggers that early leaves thePCs looking into the trapped room and perhaps
opting to close the door and move on. A simple
trap aims to keep intruders out. A complex trap
wants to lure them in, so that when it activates,
the intruders must deal with it to escape.
In general, the trigger for a complex trap
should be as foolproof as you can make it. A
complex trap represents a serious expenditureof effort and magical power. No one builds one
and makes it easy to avoid. Wisdom (Perception)and Intelligence (Investigation) checks might beunable to spot a trigger, especially a magical one,but they can still give hints about the trap before
it triggers. Blood stains, ashes, gouges in thefloor, and so on can point to the trap’s effects andgive a warning.

Initiative
A complex trap acts repeatedly, requiring you tonote its initiative. Unlike characters andmonsters, traps don’t roll for initiative. As
mechanical or magical devices, they operate in a
predictable manner. When designing a complex
trap, you must first decide how often it activates.
Complex traps fall into three categories: slow,
fast, and very fast.
Slow. These traps take time to build up theireffects. Their active elements take place on
initiative 10. This option is good for a trap thatworks alongside monsters or other guardians, as
it can give guards the chance to move out of its
active areas or force characters into them before
triggering.
Fast. These traps are designed to surprise
intruders and hit them before they can react.
Such a trap acts on initiative 20. This setting is
your best option for a complex trap. Think of it©2017 Wizards of the Coast LLC

as the default approach. It acts quickly enough tosurprise slower characters, with fast characterslike rogues, rangers, and monks having the best
chance to move out of the trap before it
activates.
Very Fast. These traps are a blur of activity,
laying waste to intruders in a few moments
unless countered. They act on both initiative 20
and 10. These traps should feature multiple
active elements, with different elements acting
on different initiative counts. Use this option fora trap that can benefit by having its elements
work in concert. For instance, on initiative 20
blades sweep across a treasure vault, driving thecharacters back into the hallway. On initiative
10, magical darts fire from statues in the hallway
while a gate falls to trap the characters.

Complex Traps and Legendary
Monsters
A complex trap is like a legendary monster in someways. It has several tricks it can use on its turn. It
remains a threat throughout the round, not just on its
turn. The trap’s active elements are like a legendary
creature’s normal actions, and its constant elements areequivalent to legendary actions (except they are tied to
specific areas in the trapped room).
While a legendary creature can move, improvise
actions, and so forth, a trap is set to a specific script,
with the potential to make a complex trap stale. That’s
where dynamic elements come in. They keep theplayers on their toes and make dealing with a complex
trap feel like a challenging, evolving situation.

Defeating Complex Traps
A complex trap is never defeated with a single
check. Instead, each successful check foils somepart of it or degrades its performance. Eachelement of the trap must be overcome
individually to foil the trap as a whole.
To start with, look at your map and consider
where the characters must be located to attempt
an action that can foil part of the trap. Most trap
designers count on the trap to protect itself. A
fighter might be able to break a whirling blade,but moving close enough to attack it requires
giving the blade a chance to strike.
Consider how the trap can be overcome.
Obvious candidates are the same sorts of checks
used to defeat simple traps, but use yourunderstanding of the trap’s design to keep otheroptions open, too. A valve leaking poison gas into
a room can be stopped up. A statue emitting adeadly aura can be pushed over and smashed.
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Attacks, spells, and special abilities can all play arole in undermining a trap.
Leave room for improvisation. If you
understand the mechanism behind how a trap
works, it makes it much easier for you to handle
the players’ ideas. Don’t create a few solutions
and wait for the players to guess the exact, rightapproach. Like everything in D&D, pick anability, assess the chance of success, and ask fora roll.
Aim at requiring three successful checks or
actions to shut down one part of a trap. The firstsuccessful check might reduce the trap
component’s save DC or attack bonus by 4. The
second successful one might halve its damage.
The final successful check might shut it down.
For trap components that don’t attack, allow
each check to reduce that element’s effectivenessby one-third. A lock’s DC is reduced or a gate
opens wide enough to allow a Small character tosqueeze through it. A mechanism pumping
poison gas into the room slows down, causing
the gas’s damage to increase slowly or not at all.
It takes time to work on a trap. Threecharacters can’t make checks right after one
another to disarm it in 6 seconds. They would
get in each other’s way and disrupt their efforts.
Once a character succeeds on a check, anothercharacter can’t attempt the same check todisable the same trap element until the end of
the successful character’s next turn.
Not all of the characters’ options must be
focused on stopping a trap. Think of whatcharacters can do to mitigate or avoid a trap’s
effects. This approach is a good way to makecharacters who might be ill-suited to disarm a
trap feel useful. An Intelligence (Investigation)
check might reveal the pattern a swinging blade
follows, giving disadvantage on its attack rolls
until the start of the character’s next turn. A
character with a shield can stand in front of adart trap, making themself a target each timeother characters trigger it.

©2017 Wizards of the Coast LLC

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