Traps can be found almost anywhere and their scope is really only limited by the imagination of the GM and/or players. This section attempts to provide a basic level of understanding regarding traps but is only a guideline. More details are likely to be added in the future.
Most traps by their nature are meant to be hidden from sight, cleverly disguised so as to fool an unsuspecting victim. As such it is assumed that any trap is given a default status of “Undetected”. This means that any player character has no notation that the trap is present.
A wise party of adventurers will of course display some awareness and attempt to detect traps, particularly when exploring an ancient crypt or a secret treasury. Detecting traps can be attempted by anyone, though those with skill in setting traps are naturally more adept at detecting them (see Secondary Skills: Traps).
Detection of traps is only possible when a character expressly states that they are “searching for traps” or that they want to “detect traps”. Doing so takes a high degree of focus, and results in cutting movement speed in half, nor can any other actions be taken at the same time. If attempting to detect traps in combat, this counts as an instant.
Detecting traps requires a stat roll, usually Perception, though in some cases Wisdom or Intellect may be appropriate. Some traps may specify an Advantage or Disadvantage to apply to the trap detector.
Passive Detection of traps is rare, but not unheard of. Most traps will be hidden well enough to prevent anyone not actively searching from finding them. But in some cases, particularly when characters have very high Perception, they may be able to detect a trap without searching for it.
Passive detection of traps relies upon Passive Perception, compare this against the detection threshold of the trap which by default is 10. Unless Passive Perception is greater than the detection threshold, the trap cannot be passively detected. This means that most traps cannot be passively detected unless a character has Perception greater than 20 (because Passive Perception is 1/2 of Perception). If the trap lists Advantage to detection that effectively reduces the detection threshold by that amount. If it has Disadvantage to detection that effectively increases the detection threshold by that amount.
Types of Traps
Simple traps have a single triggering mechanism that results in a single effect. They can typically be constructed with nothing more than a piece of rope and/or materials readily available in the wild. Some examples are:
- Snare: A simple snare is most often sued for trapping small animals for food or furs, but larger versions can be strung up to a nearby tree to snare an unsuspecting victim and have them hanging from their foot before they can even react. While they can often cut themselves down, this might result in fall damage.
- Foot Trap: Sharpened stakes placed in the ground and hidden by debris, stepping on them halts movement and inflicts 1d6 damage
- Pit Trap: A small pit covered over with twigs and leaves, stepping on it causes someone to fall through and take fall damage.
- Natural Tripwire: A vine or branch is cleverly placed to either passively trip up a passerby, or activated when pulled on, causing them to be knocked down if they fail an agility test.
- Wooden caltrops: Simple caltrops constructed of sharpened wood or thorny branches are spread in an area, while relatively easy to detect (+4 Advantage, include passive detection) they can still act as area denial. Moving through them counts as difficult terrain and inflicts 1d6 damage if failing an armor save (no dodge).
Complex traps typically still have a single triggering mechanism, though it is often more elaborate or complicated, and can result in several different effects. Complex traps could also be a combination of one or more simple traps. The trigger can be of a mechanical or magical nature, as can its effects. Either way, setting a complex trap requires purchasing or otherwise acquiring the necessary materials. Some examples are:
- Net Trap: Similar to a snare trap, but using a more elaborate mechanism to either drop a net on the victim, or pull them up into one. Depending on the situation they might be afforded a dodge test. Once trapped in a net, victims are immobilized until cut free or passing a strength test to rip themselves free.
- Hazard Pit Trap: Similar to a Simple Pit Trap, but has sharp spikes or other such hazards placed at the bottom of the pit. This adds piercing damage to the trap, in addition to the fall damage, that can range in value depending on the size and material of the spikes (a good range would be 1d6 to 2d12). Alternative hazards could include things like venomous snakes or insects.
- Hidden Pit Trap: Similar to a Simple Pit Trap, but with the cover disguised to look exactly like the surrounding floor, often through illusion magic or advanced building techniques. This results in -5 Disadvantage to being detected.
- Iron Caltrops: Purpose build iron caltrops are spread in an area, while relatively easy to detect (+5 Advantage, include passive detection) they can still act as area denial. Moving through them counts as difficult terrain and inflicts 2d6 damage if failing an armor save (no dodge).
- Dart Trap: A thin metal tripwire is rigged to fire several spring-loaded darts (or other such projectiles) from tiny holes in a nearby wall. The darts could be poisoned to add additional effects to the trap.
- Magic Trap: A pressure plate or tripwire is rigged to activate a magical device or enchanted statue that contains a particular spell such as fireball or frostbolt which then fires at the victim.
- Lock Traps: To a skilled thief, a lock is only a brief annoyance easily overcome with a got set of lock picks. To that end, some may choose to build a trap mechanism directly into a lock to further discourage over confident thieves. The simplest version of this is a spring loaded needle, often poisoned, that activates if the lock is tampered with.
Superior traps have elaborate triggering mechanisms, which often automatically reset or can be easily reloaded or reused in some way. Superior traps often have grandiose effects, capable of injuring or even killing multiple victims. Once triggered they can cause a series of combined or staged effects. In some cases, you may even grant a superior trap an initiative score, for repeated or staged effects (use 1d12+10, or simply assign an appropriate score). Some examples are:
- Collapsing Roof Trap: A tripwire or pressure plate is rigged to remove a key support from a section of roof. Rubble collapses down upon anyone underneath inflicting crushing damage if they cannot get out of the way. This could result in a chain reaction where multiple portions of the ceiling collapse in sequence. Depending on the severity, this could be a fatal trap if someone is buried before they can be rescued, or it could just result in a localized collapse and an area of rubble counting as difficult terrain.
- Rolling Rock Trap: A tripwire or pressure plate is rigged to drop a boulder that rolls down a hallway, crushing everything in its path. Anyone hit by the boulder is knocked down and takes significant crushing damage. Depending on the size of the boulder, some characters could possibly attempt to slow it down by passing a strength test.
- Multi-stage Magic Trap: similar to a magic trap, but triggering a succession of spells, each designed to piggyback off of the effects of the previous stage for maximum impact.
- Repeating Dart Trap: Similar to a dart trap, but triggering it fires continuous darts each round until its ammo is expended.