Go (Baduk): Rules and How to Play
Go is a board game for 2 players that takes about an hour (faster against the CPU). Place stones in turn and surround more territory than your opponent. Free. In-browser. No account.
Objective
Go — called Baduk in Korea and Weiqi in China — is a two-player game about surrounding territory. Black and White take turns placing stones on the intersections of a grid, and stones that are completely surrounded are captured. When both players pass, whoever controls more of the board, counting surrounded empty points and captured stones, wins.
Setup
- Two players, a board and a supply of black and white stones. The board starts empty.
- This site starts on the full-size 19×19 board used in tournaments. A game takes about an hour (faster against the CPU). Choose 9×9 for a quick game or practice, or 13×13 in between; the computer plays all three sizes.
- Stones go on the intersections (points), not inside the squares. Black plays first.
- White receives 6.5 points of komi as compensation for moving second. The half point means the game cannot end in a tie.
How to play
- Players take turns placing one stone of their colour on any empty point. A stone never moves once placed; it only leaves the board if it is captured.
- Stones of one colour that touch along the lines (not diagonally) form a group. The empty points next to a group are its liberties.
- When a group loses its last liberty, it is captured and removed, and the stones are kept as prisoners. A group with only one liberty left is said to be in atari.
- Suicide is not allowed: you may not play a stone that leaves your own group with no liberties — unless the same move captures, which gives it liberties again.
- Ko: you may not immediately recapture a single stone if that would bring back the position from before your opponent's move. Play elsewhere first (a ko threat); on your next turn the recapture is legal.
- Instead of placing a stone, you may pass.
- You can enable ring marks for stones in atari in settings (off by default). A □ marks the point you cannot retake because of ko.
Winning and scoring
- When both players pass in a row, play stops.
- You then agree which stones on the board are dead: press them to mark them, and press Confirm on both sides. If you cannot agree, press Back to play and settle it on the board.
- This site uses territory scoring (Japanese rules): count the empty points surrounded by your stones alone, add your prisoners and the dead stones taken off your opponent's territory, and give White 6.5 komi. The higher total wins.
- Empty points in seki touch both colours and count for nobody. Either player may give up at any time.
Common variants
- Area scoring (Chinese rules): count your stones on the board plus the empty points you surround; prisoners are not added. Komi is usually 7.5. The winner is nearly always the same as with territory scoring.
- Handicap: a weaker player takes Black and places two to nine stones on marked points before White's first move, usually with little or no komi. Handicap placement is not offered here yet, but a table can set komi to none.
- Superko: some rule sets, such as the AGA and New Zealand rules, forbid any move that repeats an earlier whole-board position, not only the immediate ko recapture.
- Board size: 19×19 is standard for serious play. 9×9 and 13×13 games follow the same rules and are common for learning and quick games.
Defaults on this site
| Item | Default on this site |
|---|---|
| Players | 2 players (set automatically by the party size) |
| Turn time limit | None by default (the host can set 30 or 60 seconds) |
| If someone drops mid-game | Reopening on the same device returns you to your seat. If you do not return, the CPU plays in your place. |
| Draws | In ranked play, a draw counts as halfway between a win and a loss for your rating. |
| Source of the rules | Based on the standard reference rules |
Rules supervised by Qdan, Inc. (based on the standard reference rules)
House rules
Defaults follow the standard reference rules. The party can change these.
| Name | Description | Default | Changeable |
|---|---|---|---|
| Board size | Choose 9x9, 13x13 or 19x19. The computer plays all three board sizes. | 19x19 | Yes |
| KomiKomiKomi makes up for black's advantage of moving first: it is added to white's score when the game is counted. With 6.5, the half point means there are no draws. With none, black has a clear edge, which suits games where the weaker player takes black. | Points added to white for playing second. | 6.5 | Yes |
| Atari marksAtari marksAtari means a stone or connected group has only one liberty (an empty point directly next to it) left, so the opponent can capture it with their next move. With this on, stones in atari of either colour are marked, so you notice stones about to be captured and stones you can take. | Mark groups that have only one liberty left. | Off | Yes |
| Swap who starts | Swap the black stones after each game. | On | Yes |
Terms
- Territory
- Empty points surrounded by one colour alone. Each is worth one point.
- Liberty
- An empty point next to a stone. Fill them all and the stone is captured.
- Atari
- A group with one liberty left. One more move captures it.
- Prisoner
- A captured stone. It is added to your score at the end.
- Ko
- A shape where recapturing would repeat the position. You must play elsewhere first.
- Eye
- A single empty point surrounded by one group. A group with two eyes can never be captured.
- Dead stones
- Stones both players agree cannot survive. They count like prisoners.
- Komi
- Points given to white to balance black's first move. Here it is 6.5.
FAQ
How much is komi?
6.5 points. A party can set it to none.
Can I play anywhere?
On any empty crossing, except a point where your own stone would have no liberty, and except an immediate ko recapture.
How does a game end?
Both players pass in a row. You then agree which stones are dead, press Confirm on both sides, and the score is counted.
What if we cannot agree on dead stones?
Press Back to play. Settle the position on the board, then pass again.
How is seki counted?
Empty points touching both colours belong to neither side.
Can a game be drawn?
Not with 6.5 komi. With komi set to none, an equal count is a draw.
What is the difference between 9x9 and 19x19?
19x19 is the default full-size board; allow about an hour per game (faster against the CPU). Choose 9x9 for a quick game or practice, or 13x13 in between. All three sizes support both human and computer opponents.
Play now with these rules
Last updated 2026-10-17 · Run by Qdan, Inc.