1998-12-01 last update, 1997-01-16 first day, Robert Jasiek

IGS Rules

Introduction

IGS ( telnet igs.joyjoy.net 6969) has two rule sets: these rules and GOE rules. Both have been implemented by Tim Casey. GOE rules are based on the Ing 1991 rules. The IGS rules are designed to provide players from the whole world with a simple set resembling Japanese rules. Special rulings are omitted in favour of void games. The rules use basic ko, forbidden suicide, byoyomi, and Japanese handicap. Confirmation of life and death at the game end is left to the players' agreement. Territory is monochrome surrounded empty board points plus removed opponent's stones. Special features are added.

Rules of Play

Start

• The two players of a go game play black respectively white stones on a grid board.
• Before the start of a game the players agree on accepting this rules, the match command, the colour choice, the size of the board, and the time handling.
• Before the start of a game the players should agree on the rating status, the handicap, the komi, handling of exceptional cases, and additional features.
• Black makes either the first move or sets the handicap on an empty board. This is followed by alternating moves of both players until the game stops.

Move

• A move is either a board play or a pass.
• A board play consists of placing a stone on an empty grid point and then removing all units of opponent's stones that are connected by grid lines and not adjacent to an empty grid point.
• A board play is prohibited if it leaves a unit of own stones that are connected by grid lines and not adjacent to an empty grid point.
• If a single stone removes a single stone, then no single stone may remove it immediately.

Confirmation

• Three consecutive passes stop alternating play for confirmation of life and death of stones on the board.
• All stones that could be removed by continued alternating play should be removed by agreement of both players. (clicking on stones or entering coordinates)
• Removal is ended by agreement (done); before a score check is available.
• If the players cannot agree, then play may be adjourned or resumed (undo) until a void game occurs due to the maximal number of moves of a game (uptime).

Game End

• Before the game stop a game is ended by forfeit due to run out of time.
• Before a done confirmation a game is ended by resignation of a player.
• After a confirmation both players have territory of their colour. Territory includes connected units of empty grid points that are not adjacent to an opponent's stone, with each grid point being worth one point, and removed opponent's stones, with each stone being worth one point. The komi is added to the white territory. The player with more territory wins the game.

Rules of Special Features

Komi

• When creating a game IGS proposes komi.
• Both players may agree upon another value and should set it before the second move.

Illegal Move

• Successive moves of one player, moves on occupied board points or off the board, and violations of move rules are announced but otherwise ignored.

Undo

• Before the game stop undoing a move is a right.
• Disagreement of confirmation requires undo.

Interruption

• Interruption can be caused by mutual agreement (adjourn), hardware or software problems.
• Interrupted games are to be resumed (load) as soon as possible. Otherwise a lost player has to inform his opponent. It is possible to resign a stored game.
• Intentional escaping combined with refraining resumption is considered unethical by the IGS community.
• If a resumed game is not completely saved, prior play must be repeated.

Time

• Each player starts with the same amount of time.
• The available time consists of basic time and byoyomi.
• Byoyomi requires play of a fixed number of stones within a fixed period of time.
• The use of addtime is a right. It is polite to add time in case of netlag.

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