Go is a game of surrounding space. Two players take turns placing black and white stones on the points of a grid, and whoever surrounds more of the board at the end wins. The rules fit on a page, but the game rewards a lifetime of play. Here is everything you need to start, matching how our version against the computer works.
The board and the turn
Stones go on the points where lines cross, not inside the squares. You play black and move first; the computer plays white. Once placed, a stone never moves, though it can be captured.
Our game offers the quick 9×9 board, ideal for learning, and the roomier 13×13. Press on the board to preview your stone, slide to adjust, and let go to place it.
Liberties and captures
Stones of one color joined along the lines form a group, and they live or die together.
A group’s liberties are the empty points right next to it. When a group is down to one liberty it is in atari.
Fill a group’s last liberty and it is captured: its stones come off the board.
You may not play a move that leaves your own group with no liberties (suicide) unless it captures something first.
Ko: no repeating positions
Sometimes one stone captures one stone, and the other side could capture straight back, forever. The ko rule stops this: no move may bring back an earlier board position. After a ko capture, play somewhere else first (a ko threat), then you may retake if the position has changed.
Ending the game and counting
When neither side can gain anything, pass. Two passes in a row end the game.
Stones that cannot escape capture are dead. The game marks the ones it thinks are dead; tap any group to change that, then tap Done. Keep playing resumes if you disagree.
Your score is your stones on the board plus the empty points only you surround (area scoring). Dead stones count for the side around them.
White receives komi for moving second: 7.5 points, or 6.5 on Easy. The half point means there are never ties.
Tips for your first games
Start in the corners, then the sides: they are the easiest places to make territory.
Keep your groups connected and give them room to make two separate eyes; a group with two eyes can never be captured.
When a group is in atari, either extend it to gain liberties or capture an attacking stone, and avoid moves that put your own stones in atari.
Try Easy first. Undo takes back your move and the computer’s reply, so you can explore a different idea.