Acid Dump Trap CR 3
A favorite of kobolds, this trap is triggered by opening a door built for small size creatures. The door is always left open slightly so the kobolds can use ranged weapons from behind it. Even though most creatures will have cover, the point of firing ranged weapons is to distract the creatures from searching for traps. When a creature rushes through the doorway, a bowl crashes down on the opener, pouring out its acid. The trap can be disarmed by pressing a particular rock near the doorway. This rock moves a stone underneath the bowl, providing it enough support that it will stay in place for 2 rounds. If the door is not returned to its original position by this time, the trap is triggered.
Acid drop (never miss, 2d6 acid plus 1d3 bludgeoning)
Skill Craft (traps) DC 20; Cost 3,000 gp
Riyal’s Research: Traps. Copyright 2012, Jon Brazer Enterprises. Author: Dale C. McCoy, Jr.