The initial setup is as shown on the front page. White, the attackers, start the game. After that, the two players take turns moving a stone.
All stones move as the rook in chess, that is vertically or horizontally to a free square, without jumping over blocking stones on the way. The ordinary stones are prohibited from standing on the 5 brown squares, but they are free to pass the center square. The black king having the ornament, is alone allowed on the brown squares, and is starting on the center square.
Both attackers and defenders can hit the opponent's stones, when occupying two squares on each side of the enemy stone, horizontally or vertically. Examples:
You can also hit an enemy stone with assistance of a brown square playing the role of one of the two killing stones. Examples:
However, an attacker can not kill a defender with the assistance of the center square with the king still standing there.
If a stone voluntarily moves in between two enemies, it is not killed, and you cannot kill stones by squeezing them up against the edge. So, in the following examples, no stones are killed:
The black king can be killed in the same manner, but if he stands on the center square, it is required to occupy all four neighboring squares, and if he stands on one of the neighbour squares, it is required to occupy the remaining three squares around him to kill him:
The attackers, white, win by killing the black king, the defenders, black, win by escaping to one of the four corner squares with the king. If one side along the way has no legal moves, that side looses the game (same as stalemate in chess, only in chess the game is then a draw).
To handle the problem with endless games, it is necessary to introduce rules to end games that do not progress. I don't want to introduce a draw as in chess, so the trick is to find a way to force the game to progress or to punish the player stalling the game. Here are some of my own suggestions:
(Thanks to the periodical Skalk who has published a set of rules in various languages, (C)opyright Skalk, which can be obtained at the Viking Ship Museum in Roskilde, Denmark, or through buying a nefatavl game from the publishing firm Wormianum, pages in danish.)
Last revised: 2006-10-19