Arktur - Chess with two kings

Peter Riesen invented the chess variant Arktur in 1999. The purpose of this variant was to make a game, resembling chess, for which players cannot find easily a program that plays it well, thus making it a good candidate for postal play. The game borrows some characteristics from other existing chess variants: its two main features: two kings and a random setup already appeared earlier, but not in this form.

Riesen organized in 1999 an email-tournament of the game, and announced a tournament for 2000.

Rules

The game is played on an eight by eight chess board.

The game is started as follows: Two kings, one queen, one rook, two bishops, two knights are distributed by chance on the first (white) and the eighth (black) line. Besides, the same chess pieces are opposed. The pawns are on the second (white) and the seventh (black) line.

Using this position, the game starts, and the rules of orthodox chess apply. It is not allowed to move such that one of the kings is in check after the move. There are two possibilities to win the game:

To checkmate one king
To check both kings simultaneous, so that one king cannot leave the check.

Comment

There is a great diversity of possibilities because of the position resulted by chance. Both players have to attack to avoid losing the game (because of four kings).