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Source PRPG Core Rulebook pg. 416
Traps are a common danger in dungeon environments. From gouts of white-hot flame to hails of poisoned darts, traps can serve to protect valuable treasure or stop intruders from proceeding.

Elements of a Trap

Source PRPG Core Rulebook pg. 416
All traps—mechanical or magical—have the following elements: CR, type, Perception DC, Disable Device DC, trigger, reset, and effect. Some traps might also include optional elements, such as poison or a bypass. These characteristics are described below.

Sample Traps

Source PRPG Core Rulebook pg. 420

See example traps here.

Designing a Trap

Source PRPG Core Rulebook pg. 423
Designing new traps is a simple process. Start by deciding what type of trap you want to create. Mechanical Traps: Simply select the elements you want the trap to have and add up the adjustments to the trap’s Challenge Rating that those elements require (see Table 13–3) to arrive at the trap’s final CR. From the CR you can derive the DC of the Craft (traps) checks a character must make to construct the trap (see page 424). Magic Traps: As with mechanical traps, decide what elements you want and then determine the CR of the resulting trap (see Table 13–4). If a player character wants to design and construct a magic trap, he, or an ally, must have the Craft Wondrous Item feat. In addition, he must be able to cast the spell or spells that the trap requires—or he must be able to hire an NPC to cast the spells for him.

Table 13-3: CR Modifiers for Mechanical Traps

FeatureCR Modifier
Perception DC
15 or lower-1
30 or higher+3
Disable Device DC
15 or lower-1
30 or higher+3
Reflex Save DC (Pit or Other Save-Dependent Trap
15 or lower-1
30 or higher+3
Attack Bonus (Melee or Ranged Attack Trap)
+0 or lower-2
+1 to +5-1
+6 to +10
+11 to +15+1
+16 to +20+2
Touch attack+1
Average damage+1 per 10 points of average damage
Miscellaneous Features
Alchemical deviceLevel of spell mimicked
Automatic reset+1
Multiple targets (non-damage)+1
Never miss+2
Proximity or visual trigger+1
PoisonCR of poison
Black adder venom+1
Black lotus extract+8
Blue whinnis+1
Burnt othur fumes+6
Dragon bile+6
Giant wasp poison+3
Greenblood oil+1
Insanity mist+4
Large scorpion venom+3
Malyass root paste+3
Medium spider venom+2
Purple worm poison+4
Sassone leaf residue+3
Shadow essence+3
Small centipede poison+1
Terinav root+5
Ungol dust+3
Wyvern poison+5

Table 13-4: CR Modifiers for Magic Traps

FeatureCR Modifier
Highest-level spell effect+Spell level
Damaging spell effect+1 per 10 points of average damage

Wilderness Traps

Source Ultimate Wilderness pg. 172
Skilled survivalists and trappers are adept at fashioning effective, if simple, traps from humble materials. A wilderness trap has an associated terrain wherein the raw materials for the trap are commonplace. Within these associated terrains, the base cost of each trap is calculated in sp rather than gp. Wilderness traps always have a CR of 5 or lower.

When in a trap’s associated terrain, instead of paying one-third the item’s price in raw materials, the trap maker can attempt a Survival check against the normal Craft DC of the trap + 2 × the trap’s CR. If successful, the trap maker finds the necessary materials in the wild after 1d4 hours of foraging + 1 hour per CR of the trap. She can then attempt a Craft (traps) check, also at the normal Craft DC + 2 × the trap’s CR, to build the trap, which takes another 1d4 hours + 1 hour per CR of the trap. Traps built with such crude materials don’t last long without maintenance; they have a cumulative 20% chance to break for every day they go without being tightened and reset (which requires 10 minutes of work but no additional skill checks).

At the GM’s discretion, other nonmagical mechanical traps may be considered to have associated terrains and use the wilderness trap construction rules.