I have a version of chess designed for 3 or 4 players (though I ve never gotten enough people together to play it). Basically, the game designers extended each side of the board by 3 spaces (but not extending the corners out like this, so it looks like a plus sign), and move the starting positions of each side back 3 as well. This allows more players to be added along the other two sides. Can be played in teams, with players on the same team opposite each other. If playing 3 player, the strongest player should be in the middle, since they have the disadvantage of being stuck in a pincer attack.