The Chess Variant Pages

Quad-Square Chess

A Chess Variant invented by David Howe in October, 1997


The inspiration for this game is Sub-Chess, invented by Alexander Chebotaryov in 1988. In this game, the board is really two boards in one. The central 16 squares are divided up into 64 squares, which form a board within a board.

I used a similar idea, but chose to make the squares larger, and allow more than one piece on them. This idea has been utilized to create a board that meets the 38 square board contest rules (which never stated that the squares had to be the same size!).

The Board

The board is made up of 38 squares. However, not all the squares are the same size. There are actually 32 normal sized squares, and 6 double-sized squares (which we'll call quad-squares). So, with a little cheating, I was able to create a 7x8 board with only 38 squares!


King d1; Queen e1; Bishop c1; Knight S2; Rook S1; Pawns a3,b3,c3,d3,e3,f3,g3

King d8; Queen e8; Bishop c8; Knight S4; Rook S3; Pawns a6,b6,c6,d6,e6,f6,g6

S1=(a1,b1,a2,b2) S3=(a8,b8,a8,b8)
S2=(f1,g1,f2,g2) S4=(f8,g8,f7,g7)
M1=(b4,c4,b5,c5) M2=(e4,f4,e5,f5)



  • The rules of orthodox chess apply with the following exceptions.
  • The quad-squares (ie. the double-size squares) may contain at most two pieces at any one time. The pieces may belong to the same player or to different players.
  • Moving onto and off of the quad-squares. A piece moves onto a quad-square either via a vertical/horizontal move (see diagram 1) or via a diagonal move (see diagram 2). A piece moving off of a quad-square has many more choices than one moving off of a normal square. For example, a Bishop on quad-square B can move in any of 12 different directions (actually 4 different directions with 3 different paths for each direction).

    Diagram 1
    Horizontal/Vertical Movement

    Diagram 2
    Diagonal Movement

  • The two central quad-squares (M1 and M2) may not be moved through. Once a piece moves onto one of these squares, it must stop. However, this does not apply to the Knight.
  • Knight moves as in normal chess. For the purposes of this game, the knight move is considered to be: one square horizontally or vertically, followed by one square diagonally in the same general direction. Knights still may jump intervening pieces. The Knight is the only piece that is able to move through (actually, over) a center quad-square.
  • Capturing a piece on a quad-square consists of moving a piece onto a quad-square which contains two pieces. If both pieces belong to the opponent, the moving player decides which is taken. If only one piece belongs to the opponent, then that piece is captured. If there are two pieces on a quad-square of opposite colors, one may not capture the other.

    Note: the Bishop is an exception. It may make a sacrifice capture of any opponent's piece that is alone on a quad-square. This means, not only is the opponent's piece captured, but the moving player's Bishop is also lost. Also, if the Bishop shares a quad-square with an enemy piece, it may make a non-moving sacrifice capture.

  • A Rook has the special property of pinning any enemy piece that shares a quad-square with it. The enemy piece will not be able to move out of that quad-square until either the Rook is captured, or the Rook moves out of the square.
  • Castling is allowed. The King and Rook swap positions. Otherwise, orthodox chess rules for castling.
  • There is no double square initial move for pawns.
  • Pawns may promote on S1 and S2 (for Black) and on S3 and S4 (for White). However, they are not required to. The player may decide not to promote. In such a case, the pawn then must be moved to a normal square on the last row to promote (via a capture).

Sample Game

This is my first game of Quad-Square chess. Mercifully short, but should give some idea of the flavor of the game. The board is easy to setup: Simply cover one of the edge rows (to make a 7x8 board), and cut out six squares of paper large enough to cover 4 squares, and place the papers in the proper positions.

 1. c3-M1    e6-M2
 2. M1xd6    S4xd6
 3. e1-M1    e8-e7
 4. a3-a4    c8-e6
 5. M1-c3    b6-M1
 6. c3-c2    M1xd3
 7. c2-d2    d6-M1
 8. d2-e1    M2xe3
 9. S2xd3    S3-d7
10. d1-e2    f6-M2
11. d3-S1    M2xf3+
12. e2xf3    e6-M2+
13. f3-e2    M2-S2++

Final Position

Written by David Howe.
This is an entry in the Contest to make a chess variant on a board with 38 squares.
WWW page created: October 24, 1997.