Traps

Traps are generally part of the terrain. Abilities, such as the Scourge [Legendary] ability, that seriously alter the terrain can affect traps at EL 10 and below. At EL 11 and above, traps are typically protected by wards or other precautions.

Traps come in two major types: Concealed Traps, the standard for a dungeon delve, and Open Hazards, which include everything from lava pits to ancient and deadly gear works. Concealed Traps follow all the normal rules for traps. Open Hazards follow these rules, with some changes, noted below.

Open Hazards

Many dungeons are dominated by enormous lava pits, sprawling spike traps, or just poor construction standards. We call these Open Hazards. Open Hazards occupy twice as many squares as other traps, are automatically detected, and cannot be disarmed, destroyed or otherwise deactivated, except where noted otherwise. Open Hazards have no recharge time. Creatures who remain in the area suffer the effect again at the beginning of their turns.

Generally, players should be able to overcome open hazards with enough preparation and knowledge. Such knowledge can usually be obtained with knowledge checks. Open Hazards can range from window dressing to brutally assured total party kills. Open Hazards that cover chokepoints or the majority of an encounter's battlefield increase the EL of the trap by at least 50% and should not be used regularly.

Triggering Traps

Traps, fundamentally, are all about going off. This can range from a hail of deadly arrows to a seeping poison cloud. Regardless, traps at the end of the day are defined by what happens when you trigger them. For the purposes of determining if a creature is going to trigger a given trap, traps occupy a number of contiguous squares called the trap's area. Any creature that enters a trap's area triggers the trap, suffering that trap's effect. The square of the trap's area the creature enters is called the triggered square. Some traps also require saves. Once a trap has triggered, it cannot trigger again for until a number of [Rounds] have passed, given as the trap's Recharge, unless otherwise specified.

With some time and effort, creatures may be able to circumvent a trap that they've seen operate even if they can't disarm or destroy it.