Delayed Exsplosion (Trap idea)
Here's one for you DM's that want to freak out your players (or at least make them more worried).
The players are traveling through an area which naturally houses some explosives' (like a mine, or a place with cannons). After awhile of traveling in this area, they notice that a bomb that's in their path has some how activated itself, but is thankfully far enough away to deal with itself. At least, it would have been, but when the activation runs out, it doesn't exsplode.
From that point on, the DM will roll a 1d12 every turn or every other turn. If the die lands on a 1, the bomb exsplodes. If the players mess around with, jostle, & or move the bomb (& or you just want to explode it sooner), increase the number which it can exsplode on. Of course, this leaves the players with two ways to solve this problem without harassing's the bomb enough to make it go boom. Disarming the bomb, or waiting out the bomb. When the bomb finally does go off, make it damage all tiles 5ft from it, for 2d10 damage, & all tiles 10 feet away from it, for 1d10 damage.
