Two eyes and life
Surround territory, keep your groups alive, and count at the end.
If you learn one idea in Go after capture, learn this one: a group with two separate eyes is alive forever. Your opponent cannot fill both, because filling the first would be suicide while the second still exists, and suicide is illegal. Safety in Go is not about having lots of stones. It is about having two holes that nobody is allowed to fill.
What an eye is
An eye is an empty point completely surrounded by stones of one colour, so that the opponent cannot play there without immediately losing the stone. One eye is not enough: the opponent can fill the rest of your liberties and then, finally, play in the eye as a capturing move.
Two eyes changes the arithmetic. To capture, the opponent would have to fill both, and playing into either one is illegal while the other remains empty. The group simply cannot be taken.
False eyes
An eye is only real if the stones around it are genuinely connected. If the surrounding stones are joined only at a diagonal point that the opponent can cut, the eye is false, the group is not truly connected, and it dies like a group with one eye.
Before you assume a group is alive, check the corners of each eye. That is where false eyes hide.
Practical advice on small boards
On the nine by nine board most beginners start with, living in a corner takes about six stones and living in the centre takes far more. That is the real reason strong players take corners first: it is the cheapest place to buy two eyes.
Play a game
Reading about a game is practice for playing it and nothing more. The board is open, it is free, and nothing needs installing.
Common questions
- Why do you need two eyes in Go?
- Because a group with two separate eyes cannot have its last liberty filled legally, so it can never be captured.
- What is a false eye?
- A point that looks like an eye but whose surrounding stones are not truly connected, so the opponent can cut them apart and the eye fails.
- Is a big group automatically alive?
- No. Size means nothing without eye space. Large groups die all the time, and tiny corner groups live with six stones.
More on Go
Liberties and capture
A group of stones lives by its liberties, the empty points next to it. When the last one is filled, the group is captured. The one rule the rest of Go is built on.
The ko rule
Ko stops a single capture repeating forever. What the rule is, why it exists, and how ko fights work when a one point capture is worth more than it looks.
How Go is scored
How a game of Go actually ends and who wins. Area scoring explained, why White gets komi, and how to count without arguing.
Playing Go on 9x9
Small board, whole game, twenty minutes. Why 9x9 is the best place to start Go, what changes on it, and the opening principles that work.
This site is built around Xiangqi, Chinese chess. If you enjoy Go, the rules of Xiangqi take about five minutes, and there is always somebody to play.