Doom III Chess
Strategy meets shotgun.
Published on
The Doom III mod community have created a neat little mini-game, transporting the world of id Software's first-person shooter into chess.
As long as you have a copy of Doom III and another player, you'll be able to play. The rules mostly follow the strategy classic with a few provisos. The first being if you accidentally knock a piece over, it's deemed out of play. The second stipulation is that if your opponent is taking too long in moving a piece you can shoot him, something you can also do should you find yourself about to be checkmated. Nice.
You can check the game and its instructions over at one of the many mirror sites.