Ancient alien ruins and corporate offices alike are rife with traps and defense mechanisms meant to protect valuable goods, personnel, and information. Additionally, adventuring characters sometimes encounter situations that, while not intentionally set up as traps, are just as dangerous—an unshielded power conduit in a damaged ship could prove deadly to those who aren’t careful, as could an unbalanced grav plate that might fling the unwary into a wall at high speeds. Whether the presentation of such dangers is intentional, accidental, or simply situational, all are represented using the same set of rules.
Detecting a Trap
A character can search for traps using the search task of the Perception skill. Compare the searching character’s Perception check result to the trap’s Perception DC. On a success, the character detects the trap.
Triggering a Trap
All traps have a defined trigger. If the characters fail to locate a trap while exploring an area, the trap might be triggered by a standard part of traveling, such as stepping on a floor plate or moving through a magical sensor. Some traps instead have touch triggers. These traps trigger only when a character deliberately takes an action that directly manipulates the environment—by opening a door or pulling a chain, for example.
Disabling a Trap
Characters can attempt to disable analog and technological traps with the Engineering skill, magical traps with the Mysticism skill, and most hybrid traps with either skill. Some traps require other skills to deactivate—for example, if a trap is controlled by a computer system’s control module, characters must use the Computers skill to hack the control module to prevent the computer from triggering the trap. For some traps, more than one skill can be used to disable them; often, these skill checks have different DCs and different results (which may not entirely disable the trap). Other traps require multiple skill checks to completely deactivate. The skills required to disable a trap (and the method of deactivation) are listed in the trap’s stat block.
A character must first detect a trap in order to attempt to disable it, since only through observing particular details about the trap can the character know the proper countermeasures. Even if a trap has already been triggered, characters can still attempt to deactivate the trap. Some traps no longer pose a danger once they’ve been triggered, but the PCs might be able to stop the trap’s ongoing effects, if any. Other traps might not have ongoing effects, but reset over a period of time; characters can still attempt to disable the trap during this time.
Characters gain experience points (XP) for overcoming a trap, whether they disable it, detect and then avoid it, or simply endure its effects. The XP for a trap is equal to the XP for a monster of the same CR (see Table: Experience Point Awards).
Elements of a Trap
Traps are presented in stat blocks with the following information; entries marked “optional” appear only if relevant.
Name and CR: This shows the trap’s name and CR.
XP: This indicates the amount of XP characters receive for overcoming the trap.
Type: A trap can be analog, magical, technological, or a hybrid of magical and technological. Analog traps don’t use any advanced technology or electrical power sources. Magical traps harness mystic energy to produce unusual effects. Technological traps use computers to bring other electronic machinery and weaponry to bear against their victims. Hybrid traps meld magic and technology together.
Perception: This is the DC to find the trap using Perception.
Disable: This is the DC to disable the trap using the listed skill or skills.
Trigger: A trap’s trigger determines how it is set off. Unless otherwise noted, creatures smaller than Tiny do not normally set off traps. There are several ways to trigger a trap.
Location: A location trigger goes off when a creature enters a specific area.
Proximity: A proximity trigger activates when a creature approaches within a certain distance of the trap. Proximity triggers can detect creatures through various methods (as noted in parentheses). For example, a proximity (visual) trigger goes off if it can see the target, a proximity (auditory) trigger activates if enough noise occurs near it, and a proximity (thermal) trigger detects creatures’ body heat.
Touch: A touch trigger goes off when a creature touches or tries to use a trapped item (such as a computer console).
Initiative (Optional): Some traps roll initiative to determine when they activate in a combat round.
Duration (Optional): If a trap has a duration longer than instantaneous, that is indicated here. Such a trap continues to produce its effect over multiple rounds on its initiative count.
Reset: This lists the amount of time it takes for a trap to reset itself automatically; an immediate reset takes no time, which means the trap can trigger every round. Some traps have a manual reset, which means that someone must reset the trap manually. A trap with a reset entry of “none” is a single-use trap. Even if a trap resets, the group can get XP for overcoming it only once. PCs can attempt to disable a trap during its reset period at much lower risk than normal, since there’s no danger of setting off the trap; they can even take 20 (see page 133), as long as they can finish taking 20 before the trap resets!
Bypass (Optional): Some traps have a bypass mechanism that allows the trap’s creator or other users to temporarily disarm the trap. This can be a lock (requiring a successful Engineering check to disable), a hidden switch (requiring a successful Perception check to locate), a hidden lock (requiring a successful Perception check to locate and a successful Engineering check to disable), or some other method (such as a keypad that requires either the correct passcode or a successful Computers check to hack). Details of the bypass mechanism and any skill check necessary to activate the bypass are listed in this entry.
Effect: This lists the effect the trap has on those that trigger it. This usually takes the form of an attack, a damaging effect, or some other kind of spell effect, though some traps produce 0 special effects (for example, mind-altering gases). Some traps (especially those with durations) have an initial effect, which occurs on the round the trap is triggered, and a secondary effect, which occurs on subsequent rounds. This entry notes the trap’s attack bonus (if any), the damage the trap deals, which saving throw the target must attempt to avoid or reduce the trap’s effects, and any other pertinent information.
Multiple Targets: A trap normally affects only a single creature (usually the one that triggered it); if a trap affects multiple targets, this entry notes which targets are affected.
Never Miss: Some traps can’t be avoided. Such a trap has no attack bonus or a saving throw to avoid (though it might allow a saving throw to reduce damage). It always has an onset delay.
Onset Delay: Some trap effects do not occur immediately. An onset delay is the amount of time between when the trap is sprung and when it deals damage.
Designing a Trap
To design a new trap, decide what CR you want the trap to have and consult Table 11–14: Trap Statistics on page 412 for guidance on the various statistics of a trap at that CR. These are only guidelines, however. Feel free to adjust a trap’s statistics, though you should avoid changing these numbers to values corresponding to a CR more than 2 higher or lower than the trap’s CR.
- Perception and Disable DCs: All traps require Perception and disable DCs. If the trap requires multiple checks to disable, use the DC for a trap with a CR 2 lower than your trap. If the trap has a bypass mechanism, use this DC for detecting and disabling the bypass as well.
- Initiative: If it is important when your trap acts in combat, use this bonus to calculate the trap’s initiative.
- EAC/KAC: If the mechanical parts of your trap can be attacked, these values help determine how easy they are to hit.
- Good and Poor Saves: If PCs use special attacks that can target objects against the trap, these values can be used for the trap’s Fortitude and Reflex saves. You decide which is a good save and which is a poor save for your trap. Traps don’t normally need Will saves, but if necessary, a trap’s Will save is a poor save.
- HP: Crucial parts of some traps can be damaged and should have the listed number of Hit Points. Traps are immune to anything an object is immune to unless otherwise noted. Traps also have hardness based on their material. A trap reduced to 0 HP is destroyed. Destroying a trap might set off a final component of the trap, like an explosion. Traps never have Stamina Points.
- Attack and Damage: The table lists the trap’s attack bonus and its average damage, if any, but consider reducing this damage if a trap has multiple attacks or affects multiple targets.
- Save DC: If a trap affects its victims by means of an area effect, a spell, a poison, or another special ability, use the listed DC for the appropriate saving throw.
Table: Trap Statistics
|CR||Perception DC||Disable DC||Initiative||EAC/KAC||Good Save||Poor Save||HP||Attack||Damage||Save DC|