activates the trap
when a creature approaches within a certain distance of it. A proximity trigger
differs from a location trigger
in that the creature need not be standing in a particular square. Creatures that are flying can spring a trap
with a proximity trigger
but not one with a location trigger
. Mechanical proximity
triggers are extremely sensitive to the slightest change in the air. This makes them useful only in places such as crypts, where the air is unusually still.
for magic traps
works like an actual eye, springing the trap whenever it "sees" something. A trap with a visual trigger
requires the casting of arcane eye, clairvoyance,
or true seeing
during its construction. Sight range and the Spot
bonus conferred on the trap
depend on the spell
chosen, as shown.
||Line of sight (unlimited range)
||One preselected location
||Line of sight (up to 120 ft.)
A touch trigger
, which springs the trap
when touched, is one of the simplest kinds of trigger
to construct. This trigger
may be physically attached to the part of the mechanism that deals the damage
or it may not. You can make a magic touch trigger
by adding alarm
to the trap
and reducing the area of the effect to cover
only the trigger spot
periodically springs the trap
after a certain duration has passed.
Short of completely rebuilding the trap, there's no way to trigger
it more than once. Spell traps
have no reset
To get the trap
functioning again, you must repair
Resetting the trap requires someone to move the parts back into place. This is the kind of reset
element most mechanical traps
resets itself, either immediately or after a timed
Repairing and Resetting Mechanical Traps
Repairing a mechanical trap
requires a Craft
(trapmaking) check against a DC equal to the one for building it. The cost for raw materials is one-fifth of the trap's original market price. To calculate how long it takes to fix a trap, use the same calculations you would for building it, but use the cost of the raw materials required for repair
in place of the market price.
Resetting a trap
usually takes only a minute or so. For a trap
with a more difficult reset
method, you should set the time and labor required.
Bypass (Optional Element)
If the builder of a trap wants to be able to move past the trap after it is created or placed, it's a good idea to build in a bypass mechanism -something that temporarily disarms the trap. Bypass elements are typically used only with mechanical traps
; spell traps
usually have built-in allowances for the caster to bypass them.
A hidden lock
combines the features above, requiring a DC 25 Search
check to locate and a DC 30 Open Lock
check to open.
Search and Disable Device DCs
Attack Bonus/Saving Throw DC
These are holes (covered or not) that characters can fall into and take damage
. A pit
needs no attack roll
, but a successful Reflex save (DC set by the builder) avoids it. Other save-dependent mechanical traps
also fall into this category.
in dungeons come in three basic varieties: uncovered, covered, and chasms. Pits
and chasms can be defeated by judicious application of the Climb
skill, the Jump
skill, or various magical means.
serve mainly to discourage intruders from going a certain way, although they cause much grief to characters who stumble into them in the dark, and they can greatly complicate a melee taking place nearby.
are much more dangerous. They can be detected with a DC 20 Search
check, but only if the character is taking the time to carefully examine the area before walking across it. A character who fails to detect a covered pit is still entitled to a DC 20 Reflex save to avoid falling
into it. However, if she was running or moving recklessly at the time, she gets no saving throw
and falls automatically.
coverings can be as simple as piled refuse (straw, leaves, sticks, garbage), a large rug, or an actual trapdoor concealed to appear as a normal part of the floor
. Such a trapdoor usually swings open when enough weight (usually about 50 to 80 pounds) is placed upon it. Devious trap
builders sometimes design trapdoors so that they spring back shut after they open. The trapdoor might lock
once it's back in place, leaving the stranded character well and truly trapped. Opening such a trapdoor is just as difficult as opening a regular door
(assuming the trapped character can reach it), and a DC 13 Strength check is needed to keep a spring-loaded door
often have something nastier than just a hard floor
at the bottom. A trap designer may put spikes, monsters, or a pool of acid, lava, or even water at the bottom. Spikes at the bottom of a pit deal damage
as daggers with a +10 attack bonus
and a +1 bonus on damage
for every 10 feet of the fall (to a maximum bonus on damage
of +5). If the pit has multiple spikes, a falling
victim is attacked by 1d4 of them. This damage
is in addition to any damage
from the fall itself.
Monsters sometimes live in pits
. Any monster that can fit into the pit might have been placed there by the dungeon's designer, or might simply have fallen in and not been able to climb
A secondary trap
, mechanical or magical, at the bottom of a pit
can be particularly deadly. Activated by a falling
victim, the secondary trap
attacks the already injured character when she's least ready
Ranged Attack Traps:
fling darts, arrows, spears, or the like at whoever activated the trap. The builder sets the attack bonus
. A ranged attack trap
can be configured to simulate the effect of a composite bow with a high strength rating which provides the trap with a bonus on damage
equal to its strength rating.
Melee Attack Traps:
feature such obstacles as sharp blades that emerge from walls
and stone blocks that fall from ceilings. Once again, the builder sets the attack bonus
The effect of a trap is what happens to those who spring it. Usually this takes the form of either damage
or a spell
effect, but some traps
Ranged Attack Traps:
deal whatever damage
their ammunition normally would. If a trap is constructed with a high strength rating, it has a corresponding bonus on damage
Melee Attack Traps:
deal the same damage
as the melee weapons they "wield." In the case of a falling
stone block, you can assign any amount of bludgeoning damage
you like, but remember that whoever resets the trap has to lift that stone back into place.
A melee attack trap
can be constructed with a built-in bonus on damage
rolls, just as if the trap itself had a high Strength score.
Miscellaneous Trap Features
include optional features that can make them considerably more deadly. The most common such features are discussed below.
Any trap that involves a danger of drowning is in this category. Traps
usually have the never miss
and onset delay
features (see below).
Multiple Target: Traps
with this feature can affect more than one character.
that employ poison
are deadlier than their nonpoisonous counterparts, so they have correspondingly higher CRs. To determine the CR modifier for a given poison
, consult Table: CR Modifiers for Mechanical Traps
. Only injury, contact, and inhaled poisons are suitable for traps; ingested types are not. Some traps simply deal the poison
. Others deal damage
with ranged or melee attacks as well.
If something other than spikes waits at the bottom of a pit
, it's best to treat that as a separate trap (see Multiple Traps
, below) with a location trigger
that activates on any significant impact, such as a falling
This feature applies to any trap
that needs only a successful touch attack
(melee or ranged) to hit.