Undo, passing and scoring

Undo

You can take back your move only before your opponent replies — the Undo button appears while it is their turn. What happens next depends on the game:

• Usually, it's a request. Your opponent gets Accept or Decline, and can't play on until they answer. If they decline, the move stands and you can't ask again for that move.
• In correspondence, a fresh slip is free. If you undo within 5 minutes of moving and your opponent isn't online, the move is taken back straight away — they never saw it, so there is nothing to ask.
• Real-time games always ask, however quickly you undo: your opponent is at the board.
• Against KataGo the rule is reversed — see Playing against KataGo.

Passing and scoring

When both players pass in a row, play stops and the dead stones are marked:

1. The player whose pass ended the game marks first — right away. A message asks you to click each dead group (clicking a group again brings it back to life), then press Done.
2. Their opponent confirms. They see the marking and the running score; pressing Done without changes accepts it and the game ends. If they change the marking and press Done, it goes back to the first player to look at again, until one of you accepts without changes.

A game in scoring stays open for you — no Next game button — until you have pressed Done on your part. Disagree about whether the game is really over? Either player can press Resume playing, which takes back both passes. The player who made the second pass can also Undo it while marking, under the rules above.