2004-06-25 newest contents, 2006-03-23 last update, 2004-06-25 first day, Robert Jasiek


New Amateur-Japanese Rules

[Copyright like for the Japanese 2003 Rules]


Two players play the game with stones and a board. One player, called Black, uses black stones; the other player, called White, uses white stones. The board is a grid of lines and their intersections.

As a default, the board is a grid of 19 horizontal and 19 vertical lines forming 361 intersections.

Two intersections can be adjacent along a line.

Stones of the same colour are connected if they are adjacent or if there is a chain of adjacent stones of their colour between them.

A string consists of an intersection and any intersections connected to it.

The position is the distribution of black, white, and no stones on all the specific intersections of the grid. For a play, this is given after all its removals.


A move is either a play of one’s own stone on an empty intersection, or a pass.

A play removes stones of every opposing string without adjacent empty intersection.

{no suicide} A play that does not remove stones of any opposing string may not create an own string without adjacent empty intersection.

A move-sequence is a sequence of moves that starts from a position and lets the players alternate moves.

Ko Restrictions

{basic-ko} A play may not recreate the position just before the last opposing move.

{fixed-ko} A play is prohibited if the positions just before and just after it are the same and in the same order as the positions just before and just after an earlier play of the same move-sequence.


The game consists of the following in the given order:

The alternation is a move-sequence that starts by Black from the empty grid and ends with two successive passes.

The final-position is the position at the end of the alternation.

The black-analysis / white-analysis is a move-sequence that starts by White / Black from the final-position and ends with three successive passes.


In a position, those stones of a player are immortal that are not removed in a move-sequence that starts by the opponent and in that the player always passes.

In the final-position, Black / White controls an intersection if the black-analysis / white-analysis ends with immortal stones of Black / White on the intersection or on all its adjacent intersections.


The score is

In the final-position, the result is