Traps

A trap is any device or magical ward that meets three criteria: it can inflict a sudden or unexpected result; the target would view the result as undesirable or harmful; and the creator specifically intended the harmful or undesirable result as such.
The chance to set the trap is equal to the Thief's skill value (in %), modified by luck. E.g. a Thief with 70 points in the Set Traps ability and a current luck of 1 will have a 71% chance to succeed whenever they attempt to set a trap.
The trap activates when an enemy gets within a certain distance (they don't have to walk directly over it), and shoots out projectiles that hit all enemies in the area. Allies of the thief are not affected. Thieves can set one trap per rest at level 1, plus one for every 5th level thereafter. Traps remain even after rest, so it's possible to set more, even at level 1, but there's a per-area trap limit of seven.
Every trap effect is considered nonmagical and completely bypasses magic resistance.
Traps grow more powerful with the character's level:
*1st level: Deals 2d8+5 missile damage (critical failure: 1d8+2 missile damage to self)
*11th level: Deals 2d8+5 missile damage and additionally deals 2d6 poison damage per round for the next 3 rounds (critical failure: 1d8+2 missile damage and additionally deals 1d6 poison damage per round for the next 3 rounds to self)
*16th level: Deals 3d8+5 missile damage and 4d8+2 fire damage (critical failure: 1d8+2 missile damage and 2d8+2 fire damage to self)
*21st level: Deals 3d8+5 missile damage and 20 Poison damage with no save, Slays target if a Save vs. Death with a +4 bonus is failed (critical failure: 1d8+2 missile damage and 10 Poison damage to self with no save, Slays self if a Save vs. Death is failed)
In addition to the standard thief traps, the Bounty Hunter class kit gets access to the Set Special Snare ability. Also, there are three high-level class ability traps available to thieves (except Shadowdancers) and bards: Exploding Trap, Spike Trap and Time Trap. 
Certain classes with enough skill points spend in the class ability Find Traps enables the detection and disarming of traps laid by enemies. The priest spell by the same name divines their location, but doesn't disarm them.
Setting a trap has the same cooldown period as casting a spell or using any magical item, meaning you can't use a potion or spell or set another trap for 6 seconds (1 round).
Finally, TRAPLIMIT.2DA determines the area trap limit (per class/class combo) and is equal set to the limit value +1. So, for example, if the number of traps a thief can set per rest, as determined by character level, is one, then the maximum number of traps the thief can set in that area is two (1 + 1). However, regardless of character level, the total number of traps in any area is capped at seven.
Category:Game mechanics
Category:Class abilities
Category:Article stubs
Category:Poison damage
Category:Fire damage
Category:Missile damage