Each side has a bomb piece that explodes when its fuse runs out.
How to play
Each side starts with one random non-pawn, non-king piece armed as a bomb (red number = fuse). The fuse drops by one each time its owner moves; when the fuse shows 1 the bomb is lit and cannot move, and at zero it detonates, destroying itself and every non-king piece on the 8 surrounding squares (friend or foe). Capturing an enemy bomb defuses it. A move that would leave your king in check (including after your own blast) is illegal. Win by checkmate. Pawns promote to queen.