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Rules of Go - introductory
  Difficulty: Introductory   Keywords: Rules

This page introduces the basic principles of Go rules. It allows you to learn how to play, in general terms and quickly.[12]

% If you are thinking of editing this page, please note the intention to keep the material here very introductory.

The board used here is small (5x5) compared to the sizes used in clubs, tournaments and online (typically 19x19). There are several minor variations to the rules of Go worldwide. The rules taught here are essentially the Chinese rules and while the variations matter, they are actually not important in getting the central idea of the game. It is quite easy to adapt to the different sets of rules in common use.

Table of contents Table of diagrams
A board
A point
Some stones
Before the play
A white play
After the play
Empty board
Black starts
Before the play
Black captures
After the play
Before the play
Black captures three stones
After the play
Before the play
Black captures 5 stones
After the play
Before the play
White captures
After the play
Suicide
A position
A legal move
Illegal move
Final position
Black's points
White's points
Final position


The rules given quite formally here are broken down into short sections by topic:

Players - Board - Point - Stones - Play - Start - Capture - Suicide - Repetition - Pass - Objective

Of these, the first six are descriptive, the section on Capture determines the tactics of the game, and the section on the Objective? says in a more precise way that 'go is a game of territory'.

The intermediate sections in italics are extra added explanation, not perhaps logically necessary, but intended to be helpful.


[1] Players

The game is played by two players. We call them Black and White.


[2] Board

The board is a grid of horizontal and vertical lines.

[Diagram]
A board

The example board has 5 horizontal and 5 vertical lines.



The standard size of board has been 19x19 for many centuries.


[3] Point

The lines of the board have intersections wherever they cross or touch each other. Each intersection is called a point. That includes the four corners, and the edges of the board.

[Diagram]
A point

The example board has 25 points. The red circle shows one particular point.



Go is played on the points of the board, by the placing of pieces that are traditionally called 'stones'.


[4] Stones

Black uses black stones (B). White uses white stones (W).

[Diagram]
Some stones

The example shows a board position with 4 black stones and 3 white stones. The stones are always played on the board points.



An unoccupied point is called 'empty'. The game is mostly about controlling empty points.


[5] Play

Rule of Alternation: Players take alternate turns.

The player having the turn puts one of his own stones on an empty point.

[Diagram]
Before the play

[Diagram]
A white play

White plays a white stone at the point W1.


[Diagram]
After the play


Sometimes, to complete a play, a player removes stones from the board [7].

Sometimes there are points that may not be played on a particular turn [8] [9].

Instead of playing a stone on their turn (also called a move), a player may pass [10].


So all your legal plays consist of occupying an empty point with a stone of your colour and removing any stones that are captured as a result (see below), or passing. In particular the stones don't move.


[6] Game Start

The game starts with all board points empty.

[Diagram]
Empty board


Black always plays first in the game.

[Diagram]
Black starts

In the example Black chooses to start at the point B1.



Games played with handicaps start with some stones already in place for Black, or with black placing more than one stone on the board as their first move.


[7] Capture

Rule of Capture: If a play surrounds the opponent's stone or stones completely, the player captures them and removes them from the board.


(Example 1)

[Diagram]
Before the play

The white stone is almost surrounded. It is adjacent to only one empty point, shown by the square. (An empty point adjacent to a stone or connected group of stones is called a liberty.) It is not adjacent to other nearby points, shown by circles.


[Diagram]
Black captures

Black's move B1 surrounds the white stone completely.


[Diagram]
After the play

Black's move B1 occupies the last liberty of the white stone, thus capturing it and removing it from the board.


(Example 2)

[Diagram]
Before the play

[Diagram]
Black captures three stones

[Diagram]
After the play

The three white stones WC are connected along the lines of the board, and stand or fall together.

Black's move B1 occupies their last liberty and captures them, removing them from the board to leave the third position.


(Example 3)

[Diagram]
Before the play

[Diagram]
Black captures 5 stones

[Diagram]
After the play

A play can also surround different stones at the same time even if not all of them are connected along lines. Black's move B1 captures the surrounded five white stones. For this Black occupies the last liberty of the four white stones at the top which is also the last liberty of the one white stone in the middle. All the white stones without liberties are captured and thus are removed.


(Example 4)

[Diagram]
Before the play

[Diagram]
White captures

[Diagram]
After the play

The White play W1 occupies the last liberty of the two black stones, and removes them.


It does not matter that temporarily a white stone does not have a liberty; after execution of White's play, all stones on the board have at least one liberty again, leaving a legal position.


Therefore the play of a single stone on the final liberty of a group or groups of stones causes those to be removed immediately from the board.


[8] Suicide

A player is not allowed to make a play that removes the last liberty of any of his own stones without doing the same to opposing stones (so-called suicide). This is explained further on Rules Of Go - second tutorial and Suicide.

[Diagram]
Suicide

If Black plays B1, it causes the three black stones at the top to have no liberties remaining. If this was allowed it would cause them to be captured by White and removed, hence the name suicide.



Suicide isn't useful in general, so this rule doesn't have a big practical effect on play.


[9] No Repetition

Rule of No Repetition: One may not play a move which repeats a previous board position.

This rule prevents endless repetition.

[Diagram]
A position

[Diagram]
A legal move

[Diagram]
Illegal move

White's move W1 removes a stone and Black's move B2 would remove the stone W1. However, Black would also repeat an earlier position - the position just before move W1.


Since repetition of the board position is prohibited by this rule, Black cannot play at the point 2 now in the example. Currently Black must play on a different point.

Note that on subsequent turns, the same play may be available as a legal move, because it will not be repeating the same board position.

For more on this rule, see ko.


Unlike the suicide rule, the repetition (ko) rule has a major effect on the play of games.


[10] Pass

On any turn a player may pass their turn instead of playing a stone [5] (usually when the player realises no more beneficial moves are available). The opponent then takes their turn.

When both players pass in succession, the game ends.

Note that repeating the board position [9] is only prohibited for a move. Passing obviously repeats the board position but since two passes end the game, there is no risk of endless repetition.


Passing before the game is effectively finished is usually a mistake. The game is over when both players agree that passing is correct. With a little experience one sees that passing when there is no constructive play is natural.


[11] Purpose of the game

Rule determining the winner: The purpose of the game is to occupy or surround more points than the opponent.

At the game end (when both players pass [10]) the winner is the player with the greater number of stones of his colour on the board plus empty points surrounded only by stones of his colour.

[Diagram]
Final position

[Diagram]
Black's points

13 points score for Black: 7 points occupied by black stones and 6 points surrounded by only black stones.


[Diagram]
White's points

12 points score for White: 7 points occupied by white stones and 5 points surrounded by only white stones.


In the example, Black controls more points and therefore Black wins the game.

[Diagram]
Final position


One probably needs to see how the end of the game works out in a few cases to absorb the idea. The players divide the whole area of the board between them, and the end comes when it is quite clear who controls each point (otherwise the game should continue).

Instead one can count like this (Japanese/Korean style): At the game end the winner is the player with the greater number of empty points surrounded only by stones of his colour plus the number of opponent stones he has captured. This amounts (almost) to the same thing. See scoring for more detail. But not only does one have to retain captured stones for counting, players then must concede hopeless stones.


[12] What's next?

This page is a first, basic introduction to the game. After reading it you may wish to consult

These pages should help with the first questions arising from practical play.

Some of the rules mentioned are treated differently by the various rulesets. This makes little difference to the play of the game, though. It is better not to be concerned about those matters initially.



This is a copy of the living page "Rules of Go - introductory" at Sensei's Library.
(OC) 2004 the Authors, published under the OpenContent License V1.0.