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
Bughouse chess when captured. In play over the board, a promoted pawn can be put on its side to indicate promotion. A pawn placed on the second rank may move two squares on its first move. Each player must keep the reserve or stock pieces on the table in front of the board, always visible to all players of the game. Bughouse chess is usually played with chess clocks to prevent players from waiting indefinitely for a piece. Clocks are placed on the outside so that each player can see both clocks. At the start of the game, the players with the