Rumble is a fast-paced game of creative superhero combat. Players invent new superpowers (with any effects they like) before the game then auction them off, the bid price balancing out any overpowered powers. Leftover auction currency ("energy") is then used to fight a simultaneous-reveal battle where players assign energy points to attack, defence and power usage, and are knocked out when all of their energy is lost. Played tabletop, superpowers are written on index cards, and energy and bids tracked on paper. Online, it can be played through any real time chat system, with a moderator.