How a game ends

A game ends in one of six ways:

The notation is SGF's, and it's what a game's kifu shows. A scored game can also be a draw.

Scoring a game

Play stops after two passes in a row. The game moves to scoring, a short, turn-based exchange:

1. Propose. The player who passed first proposes which stones are dead: a complete set, whole groups only. That player may instead resume play.
2. Accept or resume. The other player accepts the proposal, which ends the game with the score it gives, or resumes play.

The exchange is strictly one at a time, so there is always exactly one player due to act, which is what lets a dispute decide who has stalled. The app lets both players mark groups on their own boards before anything is signed, so the proposal usually just confirms what both already see.

The proposal must mark whole groups: a dead stone's neighbors of its own color must be dead too. A proposal that splits a group is refused.

Disagreeing

Resuming returns to play with the board, captures and the full position history kept, so superko still applies to every position so far. The proposal is cleared.

• If the proposer resumes, the proposer moves next.
• If the responder resumes, play returns to the player who was due after the passes, which is again the proposer.

A game can resume only once. After that, two passes end it immediately, scored with every stone on the board alive. There's no second proposal.

This is how disagreements end. Under area scoring, capturing a dead stone costs nothing, so whoever thinks a group is dead can simply capture it, and whoever thinks it's alive can defend it. The board settles the question, and a losing player can't stall forever with pass, pass, resume.

Move limits

Two limits bound every game. A move here is a stone or a pass.

That's three times the board's points in all, and twice its points after the resumption: enough to capture every dead stone and fill every point. A game that reaches either limit ends at once, scored like a played-out game. Real games end long before.

Resignation

Either player can resign at any time, including on the opponent's turn and during scoring. If the game has already reached the chain, a player can also resign from their wallet with resign_channel.

Time

In a ranked game, a player who runs out of time loses. The referee appends a flag to the game, and the result is B+T or W+T. Scoring is timed like play: the proposal and the response each take a turn of the clock. See Ranked clocks.

Forfeit

If a player stops responding, the opponent can take the game to the chain and force it to continue there, one turn at a time, each with a deadline. A player who misses a deadline forfeits: B+F or W+F. See Disputes.

Short games

A game shorter than 20 steps that ends offchain doesn't count for ratings, as aborted games don't on other servers. A resignation or forfeit decided onchain still counts, for the loser only.

Playing an AI anchor

The AI anchors follow the same rules. At scoring they propose the stones KataGo judges dead, accept your proposal if it gives the same winner as theirs, and otherwise resume. After a resumption they play at full strength and capture what's dead. They never resign. See AI anchors.