Kriegspiel (chess) illegal, the player tries again; if it is legal, that move stands. Each player is given information about checks and captures. They may also ask the referee if there are any legal captures with a pawn. Since the position of the opponent's pieces is unknown, Kriegspiel is not a game with perfect information. As each player cannot see his opponent's pieces, the game is sometimes referred to as "blind chess". There are several different rule sets for Kriegspiel. The most widespread rules are those used on the Internet Chess Club, where Kriegspiel is called "Wild 16". The rules are as
Four-player chess for themselves. As with regular chess, four-player chess begins with fortifications and the of pieces, but opportunities for capturing pieces (and gaining points) come about at large as each of the three opponents likewise do attacks and make threats of capture. Therefore picking friends and enemies has a political quality; ultimately the impromptu teammates will have to combat each other as only one can win. The Cox-Forbes theory of the origin of chess, though debunked, asserts that a four-player version was the earliest form of the game. A description of a four-player chess game is found in an Indian text