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
Cubic Chess Cubic Chess Cubic Chess is a chess variant invented by Vladimír Pribylinec beginning with an early version (named Echos) in 1977. The game substitutes "cubes" for the chess pieces, where four of the faces of each cube display a different chess piece (pawn, knight, bishop and rook), the two other faces are blank and are orientated to the players. This provides an efficient means (rotating the cube on a square) to change a piece's type. Kings and queens have unique cubes containing only their symbol, effectively behaving as normal. The game begins like standard chess, with a normal 8×8 chessboard,