The Chess Variant Pages

Canonical Chess Variants


Tony Paletta


Canonical Chess is a family of chess variant that blends some major elements of Xiang Qi or "Chinese Chess" with a few features influenced by western Chess. The variants described below can be played on specially designed boards or on a standard chessboard with a standard chess set.

The Board

The playing field for Canonical Chess is a diagonally-oriented board with 81 locations -- in keeping with the Xiang Qi tradition, the game may be played on the points of an 8x8 board consisting of 64 squares. A version of the game board is shown below:

Cannonical Chess setup

Locations may be identified with "oblique algebraic" notation: the "files" (a through i) are to White's right; the “ranks” (1 through 9) are to White's left (e.g., the White King stands on a1 and the Black King on i9; the vacant corners to White's left and right are a9 and i1, respectively). Some basic directions may be described as "along oblique lines" (along a rank or file) and "horizontally or vertically". The three marked areas are White' s fortress (the nine points a1-c3) at the lower end, Black's fortress (the 9 points g7-i9) at the upper end and "the crossing" running horizontally at the center of the board.

The Pieces

The chessmen and their movement patterns are as follows:

Pawn Initially slides one point obliquely forward to move or capture. It is promoted upon reaching a location fully on the opponent’s side of the crossing, and may thereafter also slide one point horizontally to move or capture.
Rook Slides one or more points along oblique lines to move or capture.
Bishop Slides one or more points like a Rook when making a non-capturing move; it captures along the same lines but must vault over a single friendly or opposing unit (the “screen”) when capturing a unit further away.
Knight Moves or captures by sliding to a destination two points away by making either (a) one step along oblique lines then continuing away one step horizontally or vertically or (b) one step horizontally or vertically then continuing away one step along oblique lines. It does not leap over occupied points. (Knight = Mao + Moa)
Queen Moves or captures by sliding one point within the fortress vertically, horizontally or along oblique lines. It may not leave the fortress area.
King Moves or captures by sliding one point within the fortress along oblique lines to a point where it is safe from capture. It may not leave the fortress area.

Other Rules

Two features from Xiang Qi are also incorporated into the rules: (1) a player may not make a move that places the two Kings in direct opposition, facing each vertically with no intervening chessmen and (2) a player may not repeat a previous position. A game is won by checkmating the opposing King or by stalemating the opponent.

Reduced Forms: Canonic Chess and Canon Chess

In addition to the game for an 81-point board, variants with very similar rules can also be played on boards with 64 points (“Canonic Chess”) or 49 points (“Canon Chess”, played with two fewer pawns per side). The arrays for these variants are shown below.

Canonic Chess Setup (64-square board

Canon Chess setup (49-square board)

Computer Play

Script and graphics files are available for playing these variants with [an error occurred while processing this directive] Zillions of Games software (with the boards shown above or on the 81 points, 64 squares or 49 interior points of a standard 8x8 chessboard). (see below).

Written by Tony Paletta.
WWW page created: December 7th, 2003.