1997-5-2 last update, 1997-4-17 first day
Robert Jasiek, jasiek@snafu.de

Japanese 1997 Rules

These rules logically improve the WWGo 1996 Rules [link] of Sakai Takeshi which are a severe improvement of the still enforced Nihon Kiin 1989 Rules [link]. Major changes occur.

Spirit

These rules must be applied in a spirit of good sense and mutual trust between the players.

Game of Go

1. Go is a game in which two players compete in skill on a board, from the beginning of the game until the game stops, to see which can take more territory. A game refers to the moves played until the end of the game.
2. Black plays first in a non-handicap game.White plays first in a handicap game.

Point of Play

The board is a grid of horizontal and vertical lines. The maximum number of horizontal and vertical lines is 19, forming 361 intersections. Plays are made on unoccupied intersections, referred to as empty points. The point on which a play is made is called a point of play.

Right to Play

One player plays the black stones; the other player plays the white stones. The two players have the right to play one stone at a time, in alternation. This is referred to as the right to play. The right to play ends when two consecutive passes are made.

Connected Units of Stones

Stones belonging to one player that are joined along adjacent intersections on the board are treated as a single connected unit, as if they were a single stone. The word "stones" as used below refers to one or more of these connected units of stones.

Stones that Can Remain on the Board

Stones remain on their points of play on the board as long as they have a horizontally or vertically adjacent empty point, called a liberty. No stones can remain on the board without a liberty.

Capture

If due to a player's move any of the opponent's stones can no longer remain on the board, those opponent's stones are removed from the board. Stones removed in this way are called prisoners. In this case, the move is completed when the stones have been removed.

Non-playable Points

A player cannot play on an empty point if any of the player's own stones would be unable to remain on the board at the completion of the move. Such a point is called a non-playable point.

Ko

A shape in which the players can alternately capture and recapture one opposing stone on the same point is called a ko. The stones that are alternately captured are called ko stones. A player whose ko stone is captured cannot recapture on the same point at his next right to play.

Stopping the Game

The game stops when the right to play ends.

Game-ending Procedure

1. After the game stops, the following game-ending procedure is carried out.
1. Unofficial alternate plays starting with the first player to pass in the last game stop and ending with successive passes.
2. Identification and verbal confirmation by both players of points to be considered as territory and of stones to be removed to become prisoners for determination of the result.
2. The game-ending procedure can be modified by returning to the point at which unofficial alternate play began.

Resumption of the Game

1. If agreement is not reached during the game-ending procedure, either player can request resumption of the game.
2. When a game is resumed at one player's request, that player's opponent has the right to play first. If both players request resumption of the game, the player who made the first of the two passes of the last game stop has the right to play first.
3. If further play occurs after the game is resumed, the game-ending procedure must be carried out again.
4. Repetition of the same position by repeated requests for resumption of the game is not allowed.

Life and Death

1. Ko stones are dead and all other stones are alive.
2. A point of a set of empty points that is surrounded by living stones of one player is an eye point. All other empty points are dame.
3. A group consists of the living stones of a maximal connected set of eye points and living stones of one player.
4. A group is in seki if it possesses dame.
5. Territory of a player and for determination of the result after play-out-to-completion are all eye points that are as a set not adjacent to a group in seki but adjacent to at least one group of the player.

Playing the Game out to Completion

1. If agreement is not reached in the game-ending procedure and neither player requests resumption of the game or if the same position is repeated during an attempt of a resumption, then either player can request that the game be played out to completion.
2. The play starts from the state at the last game stop with the player to have passed first then.
3. During the play-out-to-completion a ko stone cannot be captured more than once on the same point.
4. During the play-out-to-completion a play can be a pass for one ko.
5. During the play-out-to-completion a player needs to pass for a ko before he may recapture in it.
6. The game ends in completion when both players normally pass in succession.
7. The difference of the numbers of stones that are alive but not in seki at the game end in completion and have been played during the play-out-to-completion is added to the number of prisoners held by the player with the higher first mentioned number.

End of the Game

The game ends when agreement is reached in the game-ending procedure or when the game ends in completion. This is called the end of the game.

Determining the Result

Each point of territory and each prisoner is worth one point. After the end of the game the prisoners held by each player are subtracted from the opponent's territory, then the points of territory are counted and compared. If both players have the same amount, the game is a draw, else the player with the higher number of points wins with the difference as winning margin.

Resignation

During a game a player can end the game by admitting defeat. This is called resigning. The opponent is said to win by resignation.

No Result

If the same whole-board position is repeated during the game, a player who intends to keep repeating the same position endlessly must offer to terminate the game with no result. If the opponent refuses this offer, recreation of that same whole-board position is prohibited.

Both Players Lose

If agreement is not reached in the game-ending procedure and neither player requests play-out-to-completion, both players lose.

Illegal Moves

Moves that violate these rules cannot be made. The game is not lost by forfeit through such moves.