Masonic Chess is a chess variant invented by George R. Dekle, Sr. in 1983. The game is played on a modified chessboard whereby even-numbered ranks are indented to the right—resembling masonry brickwork. The moves of the pieces are adapted to the new geometry; in other respects the game is the same as chess.
Masonic Chess was included in World Game Review No. 10 edited by Michael Keller.
The Masonic board cells are slightly rectangular, and indentation of alternating ranks results in cants (oblique files) 30 degrees from the vertical and diagonals 30 degrees from the horizontal, the same as hexagon-based chessboards when cell vertices face the players. (For example, rooks have six directions of movement, and Masonic pawns move and capture the same as pawns in de Vasa's hexagonal chess. Masonic bishops, however, are limited to the four diagonal directions to the sides.) As with hex-based boards, three colors are used, so no two adjacent cells are the same color, and gameboard diagonals are highlighted.
The diagram shows the starting setup. All normal chess rules apply, including conventions for castling either kingside or queenside, a pawn's initial two-step option, en passant captures, promotion, and so on. But the pieces have specially-defined moves.
- A rook moves along the rank (two directions) and cants (four directions).
- A bishop moves on diagonals to the sides (four directions), or one step as a rook (six directions).
- The queen moves as a rook and bishop. (Ten directions.)
- The king moves one step as a queen.
- A knight moves in the pattern: one step as a rook, then one step as a bishop in the same (forward, backward, or sideways) direction. A knight leaps any intervening men.
- A pawn moves one step forward as a rook; on its first move it may optionally move two steps forward in the same direction. A pawn captures one step diagonally forward; en passant captures are permitted.
- de Vasa's hexagonal chess
- Also by George Dekle:
- Pritchard, D. B. (1994). "Masonic Chess". The Encyclopedia of Chess Variants. Games & Puzzles Publications. pp. 190–91. ISBN 0-9524142-0-1.
- Pritchard, D. B. (2007). "Masonic Chess". The Classified Encyclopedia of Chess Variants. John Beasley. p. 215. ISBN 978-0-9555168-0-1.
- Keller, Michael, ed. (June 1991). World Game Review (Michael Keller) (No. 10). ISSN 1041-0546.