Disputes

Offchain play needs both players to keep signing. When one stops, by disconnecting, stalling or refusing to sign a result, the other takes the game to the chain. Disputes guarantee that the game still ends, and that it can't be stolen by whoever moves last.

Opening a dispute

Either player can open a dispute from the current committed anchor with open_dispute, without a prover, and opening the game in the same transaction if it isn't open yet. This starts a fixed response window named in the terms: anywhere from 5 minutes to 7 days, an hour by default. The deadline is public.

Candidates

During the window either side may submit a newer history, proved or replayed, starting from the same frozen anchor. The channel keeps the best candidate, ranked by:

1. support: the number of authenticated changes of signer (support_turn), then
2. length: the step sequence number.

Ranking by signer changes first means a run of one player's own steps (say, a resumption followed by a move) can't outrank a branch the opponent has acknowledged merely by being longer. A checkpoint both players signed may replace an unacknowledged tail at the same support level, but never a better-supported state.

A candidate doesn't move the anchor and doesn't extend the deadline. It may be extended rather than replaced: a submission can start from the current candidate, so a transcript too long for one proof arrives in segments within one window.

Resolution

After the window, resolve_dispute promotes the best candidate to the anchor. Then:

• A finished state settles the game.
• A ranked game whose referee acknowledged the dispute returns to offchain play, and its clock keeps running.
• Otherwise the game enters forced play, with a fresh response window for the player due to move.

Resolving never awards an immediate timeout against the newly selected state, so a last-second candidate can't steal the opponent's next turn.

Forced play

In forced play the wallet due to act submits its legal steps, up to the next change of due seat, with force_steps before the deadline. The channel checks them against the anchor state and its position history, applies Go's rules, moves the anchor and starts the opponent's response window.

• If the due player doesn't act in time, the opponent calls claim_timeout and wins by abandonment (reason 130: the chain judged it, not a referee).
• Either wallet can resign at any point with resign_channel.
• Both players can sign the current epoch and state to return to offchain play (resume_channel); in a ranked game the referee alone can (resume_by_referee).

Forced steps carry no clock stamp, so a ranked game's clock pauses while it's forced and nothing is charged for that time when offchain play resumes.

Disputes in ranked games

A ranked game's referee (its keeper) keeps the clock running through a dispute. A live referee acknowledges the dispute, and resolving it returns the game to offchain play, where the clock is still ticking. A ranked game reaches forced play only while its referee is down, and the referee can bring it back on its own when it returns. See Ranked clocks.

What disputes cost

These windows guarantee liveness; they don't measure thinking time. A malicious player can force a game onchain and make it cost transactions, and players must keep their transcripts and watch for disputes to respond in time.