Here is another installment of exTRAPaganza, our Thursday over-the-top trap series.
Crystals line the walls and ceiling of this cave. They are loosely attached and easy to knock off.
Whenever a character does a physical action other than a simple move, such as jumping, a dexterity save, a melee attack, etc, they must make an average Dexterity (Acrobatics) check or they knock a crystal loose. When a crystal falls, it explodes, causing moderate fire damage to all in a 10′ radius, with an average Dexterity saving throw halving the damage. Yes, this save triggers another check for knocking off crystals. Also, the explosion has a 25% chance of knocking off another crystal.