Constricting Hall

A magical corridor whose walls slam together to crush anyone caught inside, grinding intruders between slabs of enchanted stone.

Found with Stealth DC 31. To disable, a creature must make a DC 28 Thievery (trained) check to stabilize each wall, or cast dispel magic (4th level; counteract DC 26) to counteract each wall.

Lose Form [Reaction] (occult)

Each round the trap runs a 4-action routine, losing 1 action for each wall that has been disabled. Each wall uses 1 action to slam back and forth rapidly, pummeling one creature in the hall with a wall Strike (single action, +20 attack, 2d10+11 bludgeoning). On a hit, the target is additionally knocked prone. The walls distribute the attacks as evenly as possible among creatures in the hall, and the Strikes don't apply the trap's multiple attack penalty.

Reset 1 hour.

Level 8 · Complexity Complex

Stealth DC 31

Disable

• Thievery DC 28 (trained) — to stabilize each wall, or dispel magic (4th level; counteract
• DC 26

Trigger A creature reaches the hall's midpoint

Effect The hall's walls lose their rigidity, becoming fluid and elastic. The hall becomes difficult terrain, and each creature in the hall is knocked prone unless they succeed at a DC 26 Reflex save. The trap then rolls initiative.

Reset 1 hour