Triangular chess is a

chess variant A chess variant is a game related to, derived from, or inspired by chess. Such variants can differ from chess in many different ways. "International" or "Western" chess itself is one of a family of games which have related origins and could be co ...

for two players invented by George R. Dekle Sr. in 1986. The game is played on a

hexagon In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°. Regular hexagon A regular hexagon is de ...

-shaped

gameboard A game board (or gameboard; sometimes, playing board or game map) is the surface on which one plays a board game. The oldest known game boards may date to Neolithic times; however, some scholars argue these may not have been game boards at all. ...

comprising 96 triangular cells. Each player commands a full set of chess pieces in addition to three extra pawns and a ''

unicorn The unicorn is a legendary creature that has been described since Classical antiquity, antiquity as a beast with a single large, pointed, spiraling horn (anatomy), horn projecting from its forehead. In European literature and art, the unico ...

''. Triangular chess and its variation tri-chess were included in ''World Game Review'' No. 10 edited by Michael Keller.

Game rules

The starting setup is as shown. As in

chess Chess is a board game for two players. It is an abstract strategy game that involves Perfect information, no hidden information and no elements of game of chance, chance. It is played on a square chessboard, board consisting of 64 squares arran ...

White White is the lightest color and is achromatic (having no chroma). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully (or almost fully) reflect and scatter all the visible wa ...

moves first, and the object is

checkmate Checkmate (often shortened to mate) is any game position in chess and other chess-like games in which a player's king is in check (threatened with ) and there is no possible escape. Checkmating the opponent wins the game. In chess, the king is ...

. Other standard conventions apply as well, including

castling Castling is a move in chess. It consists of moving the king (chess), king two squares toward a rook (chess), rook on the same and then moving the rook to the square that the king passed over. Castling is permitted only if neither the king ...

, the pawn's initial two-step move, the ''

en passant In chess, ''en passant'' (, "in passing") describes the capture by a Pawn (chess), pawn of an enemy pawn on the same and an adjacent that has just made an initial two-square advance. This is a special case in the rules of chess. The capturi ...

'' capture, and

promotion Promotion may refer to: Marketing * Promotion (marketing), one of the four marketing mix elements, comprising any type of marketing communication used to inform or persuade target audiences of the relative merits of a product, service, brand or i ...

at the last . The triangular geometry, however, implies special move patterns for the pieces.

Piece moves

* A rook moves in a straight line starting through a cell ''edge''. (Three directions are possible.) * A bishop moves in a straight line starting through a cell '' vertex''. (Three directions.) * The queen moves as a rook or bishop. (Six directions.) * The king moves one step as a queen. When castling, the king slides cells if (0-0); cells if (0-0-0). * A knight moves in the pattern: two steps as a bishop, then one step as a rook in an

orthogonal In mathematics, orthogonality (mathematics), orthogonality is the generalization of the geometric notion of ''perpendicularity''. Although many authors use the two terms ''perpendicular'' and ''orthogonal'' interchangeably, the term ''perpendic ...

direction. A knight leaps any intervening men. * The unicorn moves in the pattern: two steps as a rook, then one step as a rook in an orthogonal direction. Like a knight, the unicorn leaps any intervening men. * A pawn moves straight forward one step at a time, whether crossing a cell edge or vertex. On its first move it may optionally move steps straight forward. A pawn to either cell adjoining the cell immediately in front, in the same rank. * If a pawn reaches a board edge where no step straight forward exists, the pawn continues to advance toward promotion using its capture move (whether there are men to capture or not).

Tri-chess

Tri-chess is a variation of triangular chess created by Dekle in the same year. The game is for two players and is the same as triangular chess in all respects except the moves of the bishop, rook, queen, and king are increased. * A bishop moves in six directions constituting board ''diagonals''. * A rook moves in six directions along horizontal ''ranks'' or oblique ''files''. * The queen moves as a rook or bishop. (Twelve directions.) * The king moves one step as a bishop or two steps as a rook.

Notes

References

Bibliography * * *

External links

Triangular Chess
simple programs by Ed Friedlander (

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