The Chess Variant Pages

Check out Metamachy, our featured variant for December, 2023.

This page is written by the game's inventor, Dan Beyer.

Diagonal 3D Chess

This variant of 3D Chess attempts to be a logical expansion of 2D chess into a third dimension. There are no new pieces or moves. (However, as you will see there has been some “tweaking”). The goal was to retain the basic abilities of 2D pieces and process of a 2D game in the multiple permutations of 3D space.


First of all the board, or chess cube, is tilted 45 degrees on one side. The board now has a top-edge, left-edge, right-edge and bottom-edge. The pieces are set up in the left and right edges of the titled chess cube. (This can be hard to picture in the mind. see http://thehinge.3dchess/ chessboard.htm ). Thus the game is played “diagonally” through the chess cube.
The reason for this tilt (45 degrees) is intrinsically associated with the design of the pawn. (see pawn description and reasoning). In this configuration the piece sets are directly across from each other and both have exactly equal potentials and possibilities and the pawns guard the major pieces.


The King moves one cube in any direction. ( There are 26 directions. [6 classic straight],[12 diagonals] and [8 3D diagonals])

The Queen moves any number of cubes in any of the 26 directions.

The Bishop moves any number of cubes in any diagonal, 3D or otherwise. In other words, a Bishop is the same move as a Queen excluding the 6 straight directions. So, 20 directions total for a bishop.

The Rook can move in all directions except the 3D diagonals. In this way the Rook has 18 directions of travel. That is the 6 straight and the 12 diagonal.

The Knight moves much the same as it did in 2D chess (i.e. two out and one over). Apply this to three dimensions and you get 24 move possibilities surrounding the Knight.

The Pawn grows as it crosses the board 'diagonally'. Let’s use the Rook’s pawn for example. In its initial state it occupies the two cubes “in front” of the King ( i.e. the two first cubes in straight directions to the top and bottom edge of the board. Please see for visual examples of this)

When a pawn moves, it moves diagonally through the board and grows to occupy all the cubes at a right angle to its movement. I designed the pawn in this way so it would retain its blocking potential, because if one "logically" extrapolated the 2D Pawn into 3D space it is extremely weak and other pieces simply 'fly' around it. (and I didn't want to have more than 16 pieces on each side.)


The new rules are mainly concerned with the pawn occupying more than one cube at a time.
1) A pawn may take more than one piece in a single move.
2) A pawn may be taken in any cube that it occupies.


.All pictures seen here are screen shots.

DOWNLOAD the playable board at

There are instructions on how to control views, pieces, ect. Challenge a friend to a match. You may want to change the rules. Luckily the board is designed to help you do just that. Move the pieces as you see fit, make up your own rules. Use my playable board to come up with a better variant than mine. That is what games are all about.

This 'user submitted' page is a collaboration between the posting user and the Chess Variant Pages. Registered contributors to the Chess Variant Pages have the ability to post their own works, subject to review and editing by the Chess Variant Pages Editorial Staff.

By Dan Beyer.
Web page created: 2006-05-30. Web page last updated: 2006-05-30