Hidden Pit
HAZARD 0 +8 (or 0 if the trapdoor is disabled or broken)
A wooden trapdoor covers a pit that's 10 feet square and 20 feet deep.
DC 12 Thievery to remove the trapdoor
AC 10; Fort +1, Ref +1
Hardness 3, HP 12 (BT 6); Immunities critical hits, precision
Pitfall
A creature walks onto the trapdoor.
The triggering creature falls in and takes falling damage (typically 10 bludgeoning damage). That creature can use the Grab an Edge reaction to avoid falling.
Creatures can still fall into the trap, but the trapdoor must be reset manually for the trap to become hidden again.
Pathfinder GM CoreORC