From Pathfinder Society Quest #10: The Broken Scales, which isn't enabled.

Spiky Pit (3-4)

HAZARD 3

Stealth +12

Description A wooden trapdoor covers a pit that's 10 feet square and 20 feet deep.

Disable DC 12 Thievery to remove the trapdoor

AC 10; Fort +1, Ref +1

Hardness 3, HP 12 (BT 6); Immunities critical hits, precision

Pitfall

Trigger A creature walks onto the trapdoor

Effect The triggering creature falls in and takes 10 bludgeoning damage plus 3d8 piercing damage from sharp implements at the bottom of the pit. That creature can use the Grab an Edge reaction to avoid falling.

Reset Creatures can still fall into the trap, but the trapdoor must be reset manually for the trap to become hidden again.

Pathfinder Society Quest #10: The Broken ScalesOGL