Go Rules - How to Play 9×9 Go
Go is a game of connected stones, breathing space, and territory. This guide describes the exact rules used by the 9×9 board here.
The board and a legal turn
This Go board has nine lines in each direction, making 81 intersections. Stones are placed on intersections, not inside squares. Black plays first, then players alternate by placing one stone of their own color on an empty intersection. A stone never moves after it is played. There are no handicap stones in this implementation, so every game begins with an empty board and Black’s first move.
A move must leave your newly played stone or its connected group with at least one liberty, unless the move captures opposing stones and thereby creates a liberty. A liberty is an empty intersection directly north, south, east, or west of a stone or group. Diagonal contact does not connect stones and does not count as a liberty. This single idea explains both survival and capture.
Groups, liberties, and captures
Orthogonally adjacent stones of the same color form one group and share all of their liberties. If every liberty of an opposing group is filled, that group is captured: all of its stones are removed from the board. Captures can involve one stone, a chain, or a large enclosed group. Removing stones may open several empty intersections at once, which is why a placement that would otherwise be suicide can be legal when it captures.
For example, if White has one stone with empty points on two sides, Black needs to occupy both of those points—on separate turns unless another black stone already closes one side—to capture it. Do not count only the stones touching a group. Count the distinct empty intersections around the whole connected shape; a single liberty can serve several stones.
Suicide and simple ko
Suicide is forbidden unless your move immediately captures one or more opposing groups. You cannot place a stone into a point where your resulting group has no liberties and nothing is removed. This prevents deliberately disappearing stones, but permits a capture that looks surrounded before the opponent’s stones come off.
The game uses simple ko, not superko. If you capture one stone and recreate a position in which the opponent could immediately capture back to restore the just-previous board, that immediate recapture is illegal. Play elsewhere first; after an intervening move, a later recapture may be legal. Simple ko only blocks the direct repetition. It does not apply an unlimited history rule to every position ever seen.
Passing, resignation, and the end
You may pass instead of placing a stone. Two consecutive passes end the game. Local and AI games may also offer resigning; resignation concedes the game rather than changing the board rules. An online room can provide its own room controls, but the board still follows the same turn, capture, ko, and passing rules.
There is no separate dead-stone removal phase here. When the second pass ends play, scoring reads the live board exactly as it stands. That matters: if you believe a group is dead, capture it before passing rather than relying on a later negotiation screen. Empty regions adjacent only to Black count for Black; regions adjacent only to White count for White; a neutral region shared by both colors scores for nobody.
Chinese area scoring on this board
The result uses Chinese area scoring. Each player receives one point for every live stone on the board plus one point for every empty intersection in that player’s exclusively surrounded territory. White receives 7.5 komi to compensate for Black’s first move. Captured stones are not separately added to the score. Keep stones alive and surround empty points: both contribute directly.
Because the board has 81 intersections and White’s total includes a half-point, a fully filled board can theoretically be scored, while a tied numeric result is effectively impossible under the 7.5 komi. The engine may still expose a draw state where applicable; do not treat a possible interface draw as a reason to ignore the scoring formula. The practical lesson is to compare complete areas, not merely the number of prisoners you have taken.
Go rules FAQ
- Can I play on an occupied intersection?
- No. Every ordinary move must choose an empty intersection.
- Do diagonal stones protect each other?
- No. Only stones touching horizontally or vertically belong to the same group.
- Are dead stones removed after passing?
- No. The board is scored as-is, so capture groups before the two passes.
- Does this board use superko?
- No. It uses simple ko, blocking only the immediate repetition after a ko capture.
Put the rules on the board
Start a 9×9 game and pause after each capture to trace the liberties that disappeared.