Gliński's hexagonal chess

Gliński's hexagonal chess replaces the square grid with a hexagon made of 91 hexagonal cells. The board uses three colors because two colors cannot separate all diagonals correctly on this geometry. Each army has three bishops and nine pawns, as well as a king, queen, rooks, and knights.

The cell shape changes the available directions. A central cell has six neighbors sharing an edge and six additional diagonal directions. The ordinary eight-by-eight board cannot therefore be mapped onto it without changing the movement geometry.

How the pieces are adapted

• A rook slides any distance in six edge-sharing directions while its path remains clear.
• A bishop slides along six diagonal directions. Each bishop stays forever on one of the three colors, so every side begins with three bishops.
• A queen combines the rook's and bishop's movements.
• A king moves one cell in any of the twelve directions surrounding its cell.
• A knight leaps two cells along one of the six rook directions and then one cell in a direction 60 degrees to either side. It may jump over intervening pieces.
• Pawns advance toward the opposing side and capture in two oblique forward directions. Their starting cells and promotion edges, where a pawn is replaced by another piece, follow the irregular boundary.

There is no castling, the special joint move of king and rook. Check and mate retain their familiar role: a king may not remain under attack, and the game is lost when no legal defense can remove that attack.

Stalemate scoring depends on the rule set. Stalemate means that the player to move is not in check but has no legal move. Gliński's original rule awards three quarters of a point to the player who causes it and one quarter to the other player; some platforms record an ordinary half-point draw instead.

Władysław Gliński devised the variant in 1936. Its main difference from large-board games such as Grand Chess is not merely the number of cells: it changes the network of lines along which pieces move and protect one another.