As I've written before, I like my traps to be dead obvious, and completely irresistible. It's there, it's in your face, it's going to kill you - and you can't help but monkey around with it.
96. Lightning in a Bottle
In the center of this room is a lattice frame constructed of thin silver rods, running from floor to ceiling, and supporting a glass jar in the middle. Five of the silver rods terminate inside the bottle itself, while others wind around it.
The bottle holds an electrical charge, and will shock anyone touching the frame for 3d6 points of damage. Small amounts of insulation (such as touching with leather gloves, or a leather-wrapped metal pole) will reduce this to 1d6 points of damage. Thicker insulation (more than a half inch thick) will allow the rods and jar to be safely handled.
As long as the bottle remains intact, it will continue to shock those who touch it or any metal that contacts it. Breaking the bottle will fully discharge it, causing 6d6 points of electrical damage to everyone within 30’ feet. If properly insulated, the jar could be removed and used as a weapon this way.
The silver rods are worth 500 gp if recovered and sold.