Life and Death in Go: Eyes, False Eyes, and Seki

A group of stones in Go is alive if it can never be captured, and dead if the opponent can capture it whenever they choose. The dividing line is almost always the same thing: a group with two separate eyes, meaning two separate empty points fully surrounded by its own stones, is alive forever. A group with one eye or none can be killed. Learning to see that difference is the skill that turns a beginner into a player.

This page assumes you know how liberties and capture work. If two eyes are new to you, the short version is on the rules of Go, and the interactive tutorial walks through eye shapes on a real board.

Why two eyes mean alive

An eye is a liberty the opponent cannot fill. Playing into a single surrounded point would leave that stone with no liberties, which is suicide, and suicide is illegal. The only way a stone may be played into an eye is if the move captures the surrounding group in the same breath, and that needs the group to be down to that one last liberty.

With two eyes, the group always has two liberties. The opponent would have to fill one of them first, which is illegal while the other one is still there.

A black group along the top edge fully enclosed by white, with two separate marked empty points inside it. Neither can be filled, so the group can never be captured.
Two eyes at the marked points. White cannot play either one, so this group is alive however long the game runs.

Change one stone and the same group is dead.

The same black group with only one enclosed empty point left, marked, and white stones taking away the second eye. White can play the marked point and capture everything.
One eye. The marked point is black's last liberty, so white simply plays there and takes four stones.

With one eye, that eye is the group’s last liberty, and filling a last liberty is a capture, not suicide. That is the whole of it: two eyes are safe because neither can be filled first, one eye is not safe at all.

One big eye is not the same as two

A group usually does not start with two neat eyes. It starts with an open space inside it, and the fight is over whether that space can be split into two eyes or squeezed into one. Space alone is not enough. Shape decides it, and the player who moves first inside the space usually decides the shape.

A straight line of three empty points is the clearest example. Whoever plays the middle point wins.

A black group along the top edge enclosing a straight line of three empty points, with the middle one marked as the vital point white should play.
White plays the marked middle point and this group is dead. Black can capture that stone, but is left with one big eye, not two.
The same group after black plays the middle point first, splitting the three-point space into two separate marked eyes.
Black plays the middle first and the same space becomes two eyes. Same shape, opposite result.

Bigger spaces are more forgiving. Four points in a square are alive without a move. Four in a straight line can be killed by the opponent playing one of the two middle points. A six-point rectangle (two by three) in the middle of the board is alive as it stands. There is a long list of these shapes, and strong players know them by heart, but you do not need the list to play. The habit that matters is asking, every time, whether the space can still be split into two.

False eyes

Not every enclosed point is a real eye. An eye is only real if the stones around it are genuinely one group, or can be made into one. If the opponent can capture one of the surrounding stones, the eye falls apart. That is a false eye.

A black shape on the top edge with a marked point that looks like an eye, but the black stone to its right has only that point as a liberty, so white can play there and capture it.
The marked point looks like an eye. It is not: black's right-hand stone has no other liberty, so white plays there and captures it.

The quick test is the diagonal points around the eye. For a point in the middle of the board there are four diagonals, and the opponent needs two of them to make the eye false. For a point on the edge there are only two diagonals, so the opponent needs just one. In a corner there is a single diagonal, and that one point decides it.

That test is a shortcut for the real question, which is whether the stones surrounding the eye can all connect to each other without using the eye point itself. When a diagonal is not settled, check the connection directly rather than trusting the count.

False eyes matter because they are how groups die while looking alive. A group with one real eye and one false eye has one eye, and one eye is dead.

Seki: alive without eyes

There is one way to survive with no eyes at all. When two enemy groups share their last liberties and neither can fill them without being captured first, both groups simply stay on the board. That standoff is called seki, a Japanese word meaning mutual life.

A white corner group and a black group locked against each other, sharing exactly two marked empty points as their only liberties. Neither side can play there without losing the race.
Both groups have only the two marked liberties. Whoever plays first drops to one liberty and is captured, so nobody plays. Both groups live.

Play it out and you will see why it holds. If white fills one of the two points, white’s group has one liberty left and black takes the lot. If black fills one, the same thing happens in reverse. Neither player touches it, and both groups are alive at the end of the game.

Under the area scoring this site uses, the shared points in a seki count for neither player, while the stones themselves count normally for whoever owns them. Seki is rare, and you can play for months without meeting one, but it is worth recognising so you do not panic and fill it in.

Dead as it stands

Most dead groups never actually get captured. Once a group clearly cannot make two eyes, capturing it would just be a formality, so play moves on and both players agree at the end that the stones are dead.

A four-stone white group in the top-left corner enclosed by black, with only two adjacent marked empty points inside it and no way to split them into two eyes.
White's entire eye space is two points side by side. It can never become two eyes, so these four stones are dead and come off the board at the end.

When both players pass, dead stones are removed and the points they were sitting on count for whoever surrounded them. How scoring works in Go shows the count, and how a Go game ends covers what happens when the two players disagree about whether a group is dead. The safe habit for a beginner is simple: if you are not sure, do not pass. Keep playing and settle it on the board.

The reading habit to copy

Before you spend a move saving a group, ask one question: can this group make two eyes, or reach a group that already has them? If yes, work out the cheapest move that gets there and play it now, while you still have room. Eye space is far easier to keep than to build once you are surrounded.

If the answer is no, stop feeding it. Every extra stone you add to a group that cannot live is a free move handed to your opponent. Let it go, take a big point somewhere else, and use the dead stones later as ko threats if the chance comes up. Giving up stones on purpose is one of the hardest beginner habits to build and one of the most valuable, which is why strategy for beginners keeps coming back to it.

The fastest way to train this is volume. Play 9x9 games where groups are small enough to read to the end, and after each one look back at the groups that died and ask at which move they stopped being savable. That answer is usually several moves earlier than it felt at the time.

Frequently asked questions

What is an eye in Go?

An eye is an empty point surrounded on all four sides by stones of one colour, where the opponent cannot play because it would be suicide. A group with two separate eyes cannot be captured. A group with one eye can, because that eye is its last liberty and filling a last liberty is a legal capture.

What is seki in Go?

Seki is a position where two opposing groups share their remaining liberties and neither can fill them without being captured first, so both groups stay alive without either having two eyes. Nobody plays there, the position stands until the end, and under area scoring the shared empty points count for neither player.

How do you know if a group is dead?

Ask whether the space it encloses can still be split into two eyes, and whether it can connect to a group that is already alive or escape into open board. If the answer to all three is no, it is dead, whether or not anyone bothers to capture it. When you cannot tell, the answer is to keep playing rather than pass, and let the board decide.

Try it on the board →