Grande Acedrex

Alternate Names

No. of Players

Two

Equipment

Board

History

Grande Acedrex is a medieval chess variant dating back to the time of King Alfonso X of Castile. It appears in the Libro de los juegos of 1283.

Objective

The object of the game is to checkmate the opponent. The rules concerning stalemating the opponent and baring the king are not known, but can be logically reconstructed based on the rules of Shatranj (ancestral and similar to medieval Chess). In Shatranj, stalemating the opponent or baring the king of the opponent wins the game. When the player with the bare king can counter in the next move, immediately after, and bare the other king, the game becomes a draw.

Play

The king moves as modern king (one square to an arbitrary direction), but may on its first move make a jump. The white king can jump to d1, d3, f3, h3 or h1; the black king can jump to d12, d10, f10, h10, or h12; in other words the jump is two squares in horizontal, vertical or diagonal direction.

The griffion moves one square diagonal, followed by an arbitrary number of squares horizontal or vertical. The griffion may also only go one square diagonal. Note that the griffion may not jump over other pieces, and the unobstructed path must start with the diagonal movement.

The first move in the game of a unicorn in the game is as a knight. In this first move, the unicorn may not capture a piece. After this first move, the unicorn moves as a modern bishop.

The lion jumps three squares horizontally or vertically; so for example, the lion on b1 may jump to b4 or e1. The lions move is not obstructed by pieces standing on the passed squares.

The giraffe has a kind of stretched knight-move: it goes one diagonal and then three squares horizontal or vertical on. So, for instance, when on a1, the giraffe can go to b5 or e2. The giraffe jumps, i.e., its move is like a knight not obstructed by any piece standing on a passed square; e.g., from the opening setup, the giraffe on d1 can jump to e.g. c5.

The crocodile moves as a modern bishop.

The rook moves as a normal rook.

The pawn moves as a usual pawn, but does not have a double first step.

There is no castling. En passant capture?

Promotion

Promotion rule

A pawn that is moved to the last rank promotes to the type of piece that was standing on that rank in the opening setup; except when moving to f12 or f1, in which case the pawn promotes to a griffion. So, a white pawn moved to a12 promotes to a (white) rook; a white pawn moved to b12 promotes to a lion, etc.

Strategy

Variations

Sources

1. The Chess Variant Pages. http://www.chessvariants.com/historic.dir/acedrex.html