Three-Man Chess is a chess variant for three players invented by George R. Dekle, Sr. in 1984. The game is played on a hexagonal board comprising 96 quadrilateral cells. Each player controls a standard army of chess pieces.
Three-Man Chess was included in World Game Review No. 10 edited by Michael Keller.
The illustration shows the starting setup; each player's queen is placed to the left of his king. White moves first and play proceeds clockwise around the board. Pieces move the same as they do in chess, with some special features described below. Standard conventions apply including castling, a pawn's initial two-step option, en passant, and promotion. The first player to checkmate an opponent wins the game.
Special move features
- A queen or bishop moving along a long diagonal will change square colors when crossing the center of the board.
- A knight jumps in a familiar "L" pattern of the chess knight: two steps orthogonally in the same direction, then one step orthogonally to the side. Jumping by other than a (2,1) leap is not permitted.[b]
- A king pawn or queen pawn on its fourth rank has three diagonally forward ways to capture. A pawn always captures to a square of the same color.
- A pawn that reaches its fifth rank gains the ability to move orthogonally in any direction, and to capture diagonally in any direction.[c] However, it may not reenter its home one-third portion of the board.
- A pawn has three possible promotion ranks: the back rank of either opponent, and the furthest rank directly opposite the player.
A player who is stalemated loses his turns to move, unless/until an opponent plays a move that releases the stalemate condition. While stalemated, his king is still subject to checkmate, and his other pieces are still subject to capture.
- Three-player chess
- Also by George Dekle:
- This board geometry (three chessboard halves fused together) and initial setup are frequently seen in three-player chess variants, for example, Three-Player Chess (Zubrin, 1971), Drier-Schach (Schmidt Spiele, 1970s), Yalta (Spindler, 1975), and ThreeChess (ThreeChess Team, 2010). The games vary by their rulesets.
- On a regular chessboard, a knight has four different leap patterns, all resulting in identical move possibilities. But the results on the Three-Man board are not equivalent, and only a (2,1) leap is permitted.
- It transforms to the "arrow pawn" fairy piece.