How to play
Go is played by placing stones on the intersections of a grid. This version uses the small 9 × 9 board, where a whole game takes only a few minutes. Black moves first, then the players take turns.
- Place a stone or pass. On your turn, tap any empty intersection to put down one of your stones, or press Pass. Stones never move once placed.
- Liberties. The empty points right next to a stone (up, down, left, right) are its liberties. Stones of the same color that touch along the lines form a group and share their liberties.
- Capture. If your move takes away the last liberty of an enemy group, the whole group is captured and removed from the board.
- No suicide. You may not place a stone where your own group would have no liberties, unless that move captures something and so gains liberties.
- Ko. If you capture a single stone, your opponent may not immediately recapture with a move that would recreate the previous position. They have to play somewhere else first.
- The end. When both players pass in a row, the game ends and is counted.
Counting. Each player scores one point for every stone on the board, plus one point for every empty point surrounded only by their own stones. White adds 6.5 points of komi to make up for moving second, so there are no draws. Every stone on the board counts as alive: before you pass, capture enemy stones that cannot escape. The status line shows the current count as you play.
A red ring marks the last stone placed.
At the top, choose your Opponent. Against the Computer you play Black and can pick Easy, Medium or Hard. Choose Friend to play two people on one device. Hint shows a good point for the player to move, and Undo takes back one move against a friend, or your move together with the computer’s answer.
Strategy
- Corners first, then sides, then the center. Territory in a corner is surrounded by the board’s edges on two sides, so it takes the fewest stones. On a 9 × 9 board the 3-3 and 3-4 points and the center point are all strong first moves.
- Keep your stones connected. A single group with many liberties is safe. Several weak, separate groups are easy to attack.
- Two eyes make a group live. A group that surrounds two separate empty points can never be captured, because the opponent cannot fill both at once. Make sure your groups can form two eyes.
- Watch for atari. A group with one liberty left is in atari: it will be captured next move. Either extend it to gain liberties, or give it up if it cannot be saved.
- Don’t fill your own eyes. Late in the game, playing inside your own territory loses points and can even make a living group die.
- Finish cleanly. Before passing, make sure no dead enemy stones remain inside your area: in this game they would count for your opponent.
The computer plays by trying thousands of quick random games from each candidate move and choosing the one that wins most often. In our tests, Medium beat Easy and Hard beat Medium in every game we played between them.
For other games of surrounding and territory, play Amazons, or try lining up stones on the same board in Five in a Row.
