- Detecting a Trap
- Triggering a Trap
- Disabling a Trap
- Gaining Experience
- Elements of a Trap
- Designing a Trap
- Sample Traps
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 11–3: 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.
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.
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, 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 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 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.
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.
The following sample traps are listed by CR.
Pit Trap (CR 1/2)
A 10-foot-square trapdoor opens when a creature walks on top of it, dumping victims into a 20-foot-deep pit.
Trigger location; Reset manual
Laser Blast Trap (CR 1)
When sensors detect movement in the trapped room, a wall panel opens and a mounted laser rifle opens fire on the triggering creature.
Trigger location; Reset 1 minute
Effect laser +11 ranged (3d6+1 F)
Jolting Console Trap (CR 3)
When an unsuspecting creature touches the trapped console, the console sparks with electricity, shocking the triggering creature.
Trigger touch; Reset immediate; Bypass wireless key card reader (Computers DC 19 to hack)
Trash Compactor Trap (CR 5)
This trap consists of several 5-foot-square trapdoors that open when a creature stands on one, dumping the victim down a 60-foot-long chute and into a 30-foot-by-30-foot trash compactor with a single locked exit in one corner. The room is filled with debris and the floor functions as difficult terrain. One round later on the trap’s initiative count, two of the walls of the room begin closing inward, reducing the width of the room by 10 feet each round (to 20 feet on the first round, and so on). On the first round, this deals 2d6 bludgeoning damage to all nonamorphous creatures in the room. The damage increases to 8d6 on the second round, and to 32d6 on the third round. On the fourth round, the trash compactor’s exit opens to release the compressed garbage. A creature can climb back up the slippery chute with a successful DC 32 Athletics check. The gears controlling the compression mechanism have EAC 14, KAC 20, hardness 20, and 69 Hit Points.
Trigger location; Init +10; Duration 7 rounds; Reset 1 minute
Initial Effect several 60-ft.-long chutes (3d6 falling damage); Reflex DC 18 avoids; multiple targets (any target in one of several 5-ft.-square areas); Secondary Effect crushing walls (30-ft.-square room compresses 10 ft. per round, 2d6 B on first round, 8d6 B on second round, and 32d6 B on third round); Reflex DC 15 half; never miss; onset delay (1 round); multiple targets (all nonamorphous targets in the room)
|CR||Perception DC||Disable DC||Initiative||EAC/KAC||Good Save||Poor Save||HP||Attack||Damage||Save DC|
Mind Spores Trap (CR 6)
When sensors detect movement, a vent releases a spray of spores that affect the triggering creature’s mental processes.
Trigger location; Reset 1 hour
Effect spores (–4 penalty to Intelligence-, Wisdom-, and Charisma-based ability checks, skill checks, and saving throws for 1d4 hours; this is a mind-affecting effect); Will DC 16 negates; multiple targets (all targets in 30-ft. cone)
Hacker’s Curse Trap (CR 7)
When an unauthorized user attempts to hack the trapped computer console, a magical Curse script downloads into nearby technological items, which become Cursehacked. A creature using a Cursehacked item takes a –4 penalty to attack rolls (if it’s a weapon), AC (if it’s a suit of armor), skill checks (if it’s involved in attempting the skill check), and so on. The virus replicates in other technological items if they touch either a Cursehacked item or a creature carrying or wearing one. This Curse remains until removed by remove affliction or similar magic or by a successful Computers DC 35 check that takes 10 minutes for a single item.
Trigger touch; Reset 1 minute
Effect Curse (technological items become Cursehacked; this is a Curse effect); Will DC 17 negates (items of 8th level or above only; lower-level items receive no save); multiple targets (tech items carried by all creatures within 60 ft. of console)
Explosive Detonation Trap (CR 9)
When the trap detects a living creature within 5 feet, it explodes.
Trigger proximity (thermal, 5 feet); Reset none
Nanoflechette Launcher Trap (CR 11)
When sensors detect movement in the trapped room, the doors seal and five wall apertures open on its initiative count to launch nanoflechettes at everyone in the room. The trap fires nanoflechettes for 10 rounds, unless all the apertures have been closed or destroyed. An aperture has EAC 23, KAC 27, Fort +14, Ref +11, hardness 10, and 40 Hit Points. Closing or destroying one aperture reduces the damage dealt by 1d12.
Trigger location; Init +17; Duration 10 rounds; Reset 1 minute
Effect nanoflechettes +25 ranged (6d12 P); multiple targets (all targets in room)
Obedience Implant Trap (CR 12)
When the trap sees a creature within 10 feet, a lancet implants a magic microchip in the triggering creature, which falls under the telepathic control of the trap’s creator, as per dominate person (but affecting any creature). Removing the chip safely requires a 1-minute surgical procedure and a successful Medicine DC 28 check. Failure deals 3d6 slashing damage and leaves the implant in place. An implanted chip prevents magical means of ending the Spell effect. Any later successful save (such as to resist a command) renders the Spell effect dormant for 1 round rather than ending it.
Trigger proximity (visual, 10 feet); Reset manual
Disintegration Chamber Trap (CR 14)
When organic matter enters the trapped room, a disintegration beam permeates it 1 round later, atomizing everything within.
Trigger location; Reset 1 minute
Soul Upload Trap (CR 17)
One minute after living creatures enter the trapped room, they are bombarded with energy that digitizes and removes their souls, leaving their bodies lifeless husks. The digitized souls are uploaded into data modules linked to the room’s computer system. Hacking the system via a successful Computers check can release trapped souls, but it usually has a wipe module—a failed attempt might purge the souls. Casting raise dead on an affected body requires a successful DC 32 caster level check or the Spell fails.
Trigger location; Reset immediate