Collapsing Tracks
Level 9 Warder
XP 400

The tracks of the mine carts loom over the black chasm below.

Trap: Though the track here appears trustworthy, it has been sabotaged to make characters walking along it drop through and fall into the depths.Perception     DC 21: A character within 5 feet of a section of sabotaged track catches sight of where alchemical acid has eaten away at the metal bindings of the track supports.TriggerThe trap attacks when a creature enters its square.AttackImmediate Reaction      Melee
Target: All creatures within 5 feetAttack: +14 vs. ReflexHit: The target slips through the collapsing rails and falls to the bottom of the chasm, taking 4d10 damage and falling prone.Miss: The target manages to hang onto the tracks and can clamber to safety on either side of the break.Countermeasures     Dungeoneering DC 22: Before the trap is triggered, a character can use the rusted iron bars in the cavern to shore up a section of damaged track with a successful check.
     Athletics DC 12 or Athletics (without a running start) DC 22 or Acrobatics DC 5 or Acrobatics (if running) DC 18: A character who makes a successful Athletics check can jump over a section of sabotaged track without triggering it, or can jump across a section of track that has already collapsed. An Acrobatics check allows a character to move along the tracks without falling.
     Athletics DC 21 or Athletics DC 12: Characters on either side of a section of collapsed track can lash a rope across the gap with a pair of Athletics checks. A character can then climb across the gap with an easier Athletics check.

Published in Dungeon Magazine 157, page(s) 67.