This is a cross between a gas trap and a bolder trap. When set off by a trigger trap it will release jets of super-heated steam which spread of the square and fill up the nine nearest squares including its own. The steam can't pass through walls or doors meaning that this is best deployed in narrow corridors and preferably at dead-ends. Unlike the boulder trap this can be used infinite times and it can be slapped if the trigger trap is destroyed. If set off by slapping it will release more steam and fill up 2-3 extra squares but it will also be destroyed by the act.
Target: Multiple
Friendly Fire: Yes
Mana Drained: None
Cool-down: 30-60 seconds for self-triggering, 20 seconds for a slap