Editing Go (game) (section)

=== Life and death ===
{{See also|Life and death}}
While not actually mentioned in the rules of Go (at least in simpler rule sets, such as those of New Zealand and the U.S.), the concept of a ''living'' group of stones is necessary for a practical understanding of the game.{{sfn|Matthews|2002|p={{page needed|date=May 2014}}}}

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{{Goban 9x9
|ulc|  b|  b|  w|  u|  w|  b| uc|  b
|  b|  c|  b|  w|   |  w|  b|  b| rc
|  b|  b|  w|  w|   |  w|  w|  b|  b
|  w|  w|  w|   |   |   |  w|  b| rc
|  l|   |   |   |   |   |  w|  b|  b
|  w|  w|   |   |   |   |  w|  w|  w
|  b|  w|  w|  w|  w|   |  w|  b|  b
| lA|  b|  b|  b|  w|   |  w|  b| rc
|  b|  b| dc|  b|  w|  d|  w|  b|  b|22}}

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Examples of eyes (marked). The black groups at the top of the board are alive, as they have at least two eyes. The black groups at the bottom are dead as they only have one eye. The point marked ''a'' is a false eye, thus the black group with false eye ''a'' can be killed by white in two turns.
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When a group of stones is mostly surrounded and has no options to connect with friendly stones elsewhere, the status of the group is either alive, dead or ''unsettled''. A group of stones is said to be alive if it cannot be captured, even if the opponent is allowed to move first. Conversely, a group of stones is said to be dead if it cannot avoid capture, even if the owner of the group is allowed the first move. Otherwise, the group is said to be unsettled: the defending player can make it alive or the opponent can ''kill'' it, depending on who gets to play first.{{sfn|Matthews|2002|p={{page needed|date=May 2014}}}}

An [[List of Go terms|eye]] is an empty point or group of points surrounded by a group of stones. If the eye is surrounded by Black stones, White cannot play there unless such a play would take Black's last liberty and capture the Black stones. (Such a move is forbidden according to the suicide rule in most rule sets, but even if not forbidden, such a move would be a useless suicide of a White stone.)

If a Black group has two eyes, White can never capture it because White cannot remove both liberties simultaneously. If Black has only one eye, White can capture the Black group by playing in the single eye, removing Black's last liberty. Such a move is not suicide because the Black stones are removed first. In the "Examples of eyes" diagram, all the circled points are eyes. The two black groups in the upper corners are alive, as both have at least two eyes. The groups in the lower corners are dead, as both have only one eye. The group in the lower left may seem to have two eyes, but the surrounded empty point marked ''a'' is not actually an eye. White can play there and take a black stone. Such a point is often called a ''false eye''.{{sfn|Matthews|2002|p={{page needed|date=May 2014}}}}