Kriegspiel (chess) follows. The game is played with three boards, one for each player; the third is for the umpire (and spectators). Each opponent knows the exact position of just their pieces, and does not know where the opponent's pieces are (but can keep track of how many there are). Only the umpire knows the position of the game. The game proceeds in the following way: The umpire announces: Pawn promotions are not announced. Kriegspiel is sometimes used in chess problems. In these, usual variations introduced by different black moves are replaced by variations introduced by different announcements. An example of a
Three-player chess have three cells obliquely adjacent, and three cells adjacent at points. Circular boards have three- or four-sided cells, but not triangular or quadrilateral. Some variants incorporate fairy chess pieces in addition to standard chess pieces. The introduction of a third player drastically alters the style of play, even when standard pieces are used. Many chess openings are useless due to the extended board and third player. Each player must think twice as far ahead—anticipating the moves of both opponents, with the added complexity that the next player may move to attack either opponent. If a player trades off pieces with