The Chess Variant Pages

Check out Marseillais Chess, our featured variant for February, 2024.

This page is written by the game's inventor, Tony Quintanilla.


Object: This 40 square Chess variant is distinguished by its board. It's the regular Chess board set at 45 degrees, hence the name. The board was designed this way to make it 40 squares, but retain a symmetrical rectangular grid. The pieces move as they do in standard chess, but seem to move obliquely due to the orientation of the board grid. There are some exceptions: there is no castling for the King; the pawn moves along the diagonals, which are now straight, and may move forward, backward, and to the sides; the Pawn captures along the orthogonals, which are now oblique; the pawn does not have the special initial move, does not promote, and cannot capture "En-passant".

This Chess variant was designed for the Chess Variant Pages 40 square variant contest. My goal was to create something special in 40 squares. The oblique grid appeals to me because it retains something of the symmetry of a regular chess board, thus retaining the greatest useful area for the game. Its also appealing because this simple change alone is enough to give the game a very different feel without changing the rules very much. All the pieces moves as they normally do, with the exception of the Pawn. However, the feel of the pieces is very different because of the oblique grid. This is particularly true of the two pieces restricted to the orthogonals and diagonals, the Rook and the Bishop. The Pawn's move is made straight by changing its movement to the diagonals. This appealed to me because it adds another element of obliqueness and retains the forward movement of the Pawn, which is important for playability. I also enhanced its powers to give it a bigger role in the game. To compensate, I made the Pawn non-promotable.

In the opening, you will need to develop your pieces. This is not so easy because there is a wall of Pawns in front of them. So the initial effort will be to create avenues for the pieces by attacking with the Pawns, or moving them laterally to support other Pawns. The middle game develops quickly. The key here is to use careful tactics to gain a material advantage for the end game. The end game is similar to standard Chess, however, the Pawns are active combatants instead of time bombs ready to be promoted.


Oblique has an unusual setup because of the orientation of the board. The coordinates include the nodes between squares, although they play no role in the game. There is complete symmetry. Each side places the white diagonal nearest the player, and places the pieces as follows:
                                                         (White Player)
       (white diagonal)          Bishop      Queen      King     Knight
       (black diagonal)      Pawn      Rook      Bishop     Rook      Pawn
       (white diagonal)            Pawn        Pawn     Pawn        Pawn
       (black diagonal)     empty     Pawn      Pawn      Pawn      empty
       (white diagonal)           empty       empty     empty      empty

       (black diagonal)     empty     Pawn      Pawn      Pawn      empty
       (white diagonal)            Pawn        Pawn     Pawn       Pawn
       (black diagonal)     Pawn      Rook      Bishop     Rook      Pawn
       (white diagonal)         Bishop      Queen      King     Knight
                                                          (Black Player)

You can play this game with Zillions of Games, using the Zrf-file, made by Tony Quintanilla.
This is a submission in the contest to design a chess variant on a board with 40 squares.
Written by Tony Quintanilla. Webpage made by Hans Bodlaender.
WWW page created: August 11, 1999.