Go basics

The board and placing stones

Go is played on the intersections of the lines. The standard board is 19×19; beginners often use the smaller 9×9 or 13×13 boards.

Black plays first, then White; the players take turns placing one stone on an empty intersection. Once placed, a stone never moves — it can only be captured.

You can tap the 9×9 board below: Black and White take turns, and surrounded stones are captured. Tap a stone already on the board to see that group's liberties.

The goal of Go is to surround more territory with your stones than your opponent does.

Liberties and captures

The empty points directly above, below, left and right of a stone are its liberties. Stones of the same colour that touch form one group and share all of their liberties.

When the opponent fills every liberty of a group, the group is captured (taken off the board).

A group with only one liberty left is in atari: if it doesn't escape, it will be captured.

Illegal points and ko

If, after you play, your own group has no liberties and you haven't captured any of the opponent's stones, the move is suicide and is not allowed.

But if the move captures some of the opponent's stones, your group has liberties once they are removed, so the move is allowed.

A shape where both players could keep capturing one stone back and forth is called a ko. A stone that was just captured cannot be recaptured right away: the opponent must play elsewhere first, which is called finding a ko threat.

This site uses positional superko: no move may return the whole board to a position that has appeared before.

Eyes and living groups

An empty point surrounded by your own stones is an eye. The opponent can't play inside it, because that would be suicide — unless the move captures.

A group with two separate eyes can never have its last liberty filled, so the group is alive.

A group with only one eye can have its outside liberties filled, and then the opponent plays inside the eye and captures the whole group — so it is dead.

The end of the game and counting

When both players feel there is nowhere useful left to play, each passes; two passes in a row end the game.

Then mark the dead stones: stones with no hope of living are counted as captured.

This site uses Chinese area scoring: your stones on the board plus the empty points surrounded only by you make up your score.

Playing second is a disadvantage, so White gets 7.5 extra points, called komi. The half point means a game can never end in a tie.

After counting, the side with more points wins.

A few sayings to remember before you start

• Corners are gold, sides are silver, the centre is grass: territory is easiest to make in the corners, then on the sides, and hardest in the centre.
• Take the corners first, then secure or approach them, and only then extend along the sides.
• Keep your stones connected: when a group is cut in two, both halves become weak.
• You don't have to capture as soon as you have a group in atari: first think about what happens if it escapes.
• A game on a 9×9 board takes about ten minutes — a good way to practise capturing and making eyes.

Want to just try it? Start a game of Go: choose 9×9, 13×13 or 19×19 and one of five computer levels, or play with a friend on the same device.

Play Go