Go Liberties & Capture Trainer
Liberties, capture, suicide and ko on a real board. Groups with one liberty are ringed, so you can see atari rather than being told about it.
The rules, and why they are in that order
- A group of stones lives while it touches an empty point. That single idea is the whole of Go: everything about capture, about life and death, and about why the edge is dangerous follows from counting the empty points next to a group.
- Stones connect orthogonally, never diagonally. Two stones touching only at a corner are two separate groups with separate liberties, which is the most common misreading of a board.
- The order of the rules is what makes them work. When a stone is played, the opponent’s stones that have just lost their last liberty come off FIRST, and only then is the played group tested. Do it the other way round and an ordinary capture looks like suicide.
- That is why a move filling your own last liberty is legal when it captures something: taking the enemy stones off gives your group the liberties it was missing. A move that captures nothing and leaves you with none is the only true suicide.
- Ko exists because a single stone taken by a single stone can otherwise be recaptured forever. It is the only situation where the position can repeat immediately, so it is the only one the rule has to forbid.
- Scoring is deliberately not here. Territory counting differs between the Chinese and Japanese rule sets in ways that change who wins, and quietly picking one would be worse than not counting at all.
How to use
- Click a point to place a stone.
- Hover a group to see the empty points keeping it alive.
- Try to capture something, and try to play somewhere you should not.
Frequently asked questions
What is a liberty?
An empty point directly next to a group. That single idea is the whole of Go — a group lives while it touches at least one, and comes off the board when it touches none. Everything about capture, about life and death, and about why the edge is dangerous follows from counting them.
Are diagonal stones connected?
No, and this is the most common misreading of a board. Stones connect along the lines only, so two stones touching at a corner are two separate groups with separate liberties. Hover either one and you will see the tool treat them as strangers.
Can I play a move that fills my own last liberty?
Only if it captures something. The order of the rules is what makes this work: the opponent’s stones that have just lost their last liberty come off FIRST, and only then is your own group tested — by which time the space they vacated has given it liberties. A move that captures nothing and leaves you with none is the only true suicide.
What is ko?
A one-stone capture that could otherwise be taken straight back, forever. It is the only situation where the board can repeat immediately, so it is the only one the rule forbids: you must play somewhere else first. Take a single stone here and the tool will close that point to the reply and say so.
Why is a stone on the edge weaker?
Because it has fewer liberties to begin with. A stone in the middle touches four empty points, one on the edge touches three, and one in the corner only two — so it takes four stones to capture the first and two to capture the last. That is the arithmetic behind every piece of opening advice about corners.
Why is there no score?
Because territory counting differs between the Chinese and Japanese rule sets in ways that change who wins, and quietly picking one would be worse than not counting at all. This tool covers the rules everyone agrees on.
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