Go rules

Go rules are the rules of the game for the board game Go . They are not standardized internationally, and so there is a great variety of regulations that have arisen historically. Nevertheless, the set of rules used only has a significant influence on the course of the game and the result of the game in occasional exceptions. The most important international rules and rule differences are shown here. A simpler introduction to the game can be found on the Go page .

Basic generally applicable rules

Players and game material

Go is a two-player game called Black and White .

However, there are also variants for several players such as Paargo , in which each side is represented by two players who take turns and are not allowed to communicate with each other, or multi-color go , in which several players take part, each with their own stone color.

The game board is a grid of 19 horizontal and 19 vertical lines that form 361 points of intersection. This is usually a grid of black lines on a wooden board. For visual orientation, but of no importance for the course of the game, some intersection points are marked by slightly bold points (Hoshis). The handicap stones are placed on this in a handicap game. A 19 × 19 size board is standard. However, it can also be played on boards of other sizes, for example 9 × 9 or 13 × 13. The rules are the same for all board sizes. The 9 × 9 board is recommended for beginners, but experienced players also like to play a game on a smaller board.

There are black and white stones. The black player uses the black pieces and the white player uses the white ones. The number of stones is in principle unlimited; In practice, a play set has 180 pieces per color. The stones are mostly lens-shaped. The material varies; it ranges from plastic to glass to shell and slate.

Alternating trains

At the beginning the board is empty (except when default), and the stones are in a supply outside the board. The players take turns taking turns, Black begins. The player who is on the train, either its own stone from his supply on any empty intersection set or match .

Chain and freedom

A chain is a group of one or more stones of the same color that are connected by horizontal or vertical line segments. The term chain is more precisely defined as follows:

• every stone on the board belongs to exactly one chain
• two stones of the same color on adjacent intersections belong to the same chain
• different colored stones belong to different chains
• two stones of the same color, between which there is no connection at all intersections occupied by stones of this color, belong to different chains

The proximity of the intersection points is conveyed by the lines of the board, therefore intersection points or stones can only be horizontally or vertically adjacent, but not diagonally.

A freedom of a chain is an empty intersection that is adjacent to a stone of the chain. For example, if a chain only consists of a single stone, it can have up to four degrees of freedom, because in the middle of the board each intersection point has four neighboring points, while a point on the edge has three and one in the corner has only two neighboring points. A stone has a freedom if it belongs to a chain that has a freedom.

Beat

If there are opposing stones without freedom after a stone has been placed, then these are removed from the board. They say: they are beaten . This removal is part of the move. If there are also your own stones without freedom, they will not be removed.

It can happen that after placing your own stones without freedom, while all opposing stones still have freedom (keyword: suicide). Depending on the rules, it is either that such a setting is not allowed, or that in this case one's own stones are struck without freedom.

After removing the captured stones, every chain on the board has a freedom, because if there are own and opposing stones without freedom, your own get freedom again by removing the opposing ones.

Depending on the assessment rule, stones removed by hitting are either returned to the stone supply or are kept separately as prisoners .

Suicide / not suicide

Suicide by Black

No suicide

Depending on the rules, suicide , setting and removing your own stones is allowed or prohibited.

When setting a stone, it can happen that it no longer has any freedom. If opposing stones are captured, these are first removed from the board. In this case, the stone that was originally set or the chain to which it belongs has also been given at least one freedom again, and it is not suicide.

Suicide allowed

If all opposing stones have a freedom after placing, your own stones are captured without freedom, i.e. removed from the board. This removal is part of the move. Depending on the evaluation rule, the stones removed by suicide are either given back to the stone supply or kept separately as prisoners of the opponent, just like when striking opposing stones.

Rules with allowed suicide are the New Zealand rules and the Ing rules.

In strategic practice, suicide rarely makes sense. However, it can occur as a knockout threat (intermediate move before knocking back a knockout) or in catching races (Japanese semeai , English capturing races ) and then be decisive.

Suicide prohibited

Placing on an intersection is forbidden if the piece that was placed would not have any freedom, while all opposing pieces would still have freedom and would therefore not be captured.

Regulations with prohibited suicide include the Chinese, Japanese, Korean, and US rules.

Restriction of positional repetition

In order to prevent endless repetitions or make them pointless, positional repetition is restricted. There are various possible rules for this. Since they almost always restrict the setting in a Kō , one also speaks of Kō rules.

A position is a specific distribution of black and / or white pieces on the intersection of the board. If stones are captured when setting, a new position only arises after the move has been completed, after the captured stones have been removed.

Superco

• Positional SuperKo : A bet may not restore an earlier position during the game. This rule is used by the Simplified Ing rules, which the EGF (European Go Federation) uses in some European tournaments.
• Situational superco : An earlier position may not be repeated if it is the same player's turn. This variant is used by the US and New Zealand rules.

With the Chinese rules, it is unclear whether the superco rule applies or whether it is overridden by the referee rules.

Standard knockout rule and no-result rule

Two consecutive moves (except passing) may not restore the original position.

This standard ko rule is only relevant within a single Kos; However, this is by far the most common use case for rules that restrict positional repetition.

If a position is repeated, the game can immediately and exceptionally end with the result “No result” if both players agree on it.

The players will agree if both do not pass at all or the same number of times in a cycle (example: triple knockout). Depending on the scoring rule, they may not agree if one player passes more often than the other in a cycle (example: Sending-2-Returning-1). Whoever places more stones in the cycle gives the opponent more prisoners and worsens his situation. He is thus forced to deviate from the cycle.

The combination of the standard knockout rule and no-result rule is used in Japanese rules, Korean rules, and oral rules similar to them.

Other variants

There are other variants, some of which are simple, some of which are extremely complicated. The Ing-Ko rules are an example.

Game flow

A game of Go is divided into phases. That varies depending on the rules.

Simple rules

A game consists of the following phases:

1. Alternating pulling
2. rating

The alternating drawing ends when one player passes and then the other player also passes.

This simple process is particularly recommended for beginners. In practice, it means that the players continue to bet until all opposing chains have been beaten where this can be achieved. The area evaluation can be used as an evaluation.

Rules with agreement on removal

A game consists of the following phases:

1. Alternating pulling
2. Agreement on removal
3. Continuation of alternating dragging
4. rating

The Alternate Draw ends when both players pass in succession. The same applies to the continuation of the alternating drawing. If only one player passes, he has the right to continue playing after the opponent's next move.

If, after the alternate drawing, the players agree which stones are to be removed, the game is evaluated. The stones removed are added to the prisoners (area assessment) or not taken into account (area assessment) depending on the assessment method.

If the players do not agree, the alternate draw continues. The player who passed last has the second move. A repeated continuation of the alternating drawing is possible.

The following sets of rules use a removal convention: Chinese, US, French, New Zealand, Ing, Simplified Ing rules. Either the area assessment or the area assessment with pass stones can be used as an assessment. Traditional area assessment is unsuitable for the removal agreement because there cannot be disagreement between the players.

Rules with determination of status

A game consists of the following phases:

1. Alternating pulling
2. Determination of status
3. rating

The alternating drawing ends when one player passes and then the other player also passes.

When determining the status, the correct status is determined: life or death of each chain, seci versus non-seci of each chain, area (including assignment to a player) versus non-area of ​​each intersection. Experienced players usually carry out the determination of status implicitly and averbally by starting the evaluation immediately after the alternating draw and interpreting the determination of status as part of it. In the event of a dispute, however, an exact and explicit determination of the status is necessary.

Japanese rules, Korean rules, and oral rules similar to these use determination of status as a phase. Often there is another phase of filling queen and teire, as well as resumption procedures. Only the traditional area evaluation is suitable as an evaluation, because only it uses status aspects as essential parts of the set of rules.

The details of the determination of status are beyond the scope of this page. See the 2003 Japanese Rules Commentary .

rating

The evaluation is the central feature of a set of rules and varies depending on the set of rules. There are three simple, in principle different evaluation options:

1. Stone evaluation: only occupied intersections are evaluated.
2. Area evaluation: occupied and free intersections are evaluated.
3. Area evaluation: Only free intersections are evaluated.

Only when assessing the area must stones cut also be taken into account to determine the final result.

The stone rating is certainly the simplest and oldest rating function. The area assessment was introduced in order to avoid boring clogging of the free intersections at the end of the game. In this point (quick counting) the area evaluation goes even further, but it is now unclear whether such rules can still be formulated logically consistent (the Japanese Go rules are proven to be inconsistent [ Sources: Commentary on the official Japanese rules from 1989, error of Rules of the Amateur Go World Championship 1979 ]).

Stone rating

Each player's score is the number of stones they have on the board. The stone rating is also known as the Traditional Chinese Rating. In practice, the area (occupied and free intersections) of one's own positions was counted, but a “2-point tax” was deducted for each group in order to avoid the boring filling of the board at the end of the game. This rating was the dominant board rating in China well into the 20th century and was pushed back with the beginning of the Japanese invasion in 1911. Their principal advantage is: There are no disputes about the evaluation of the free intersections. The connection between the visual perception of the position at the end of the alternating drawing and the number of points is simple. The direct derivation of the score from that position is thus obvious.

Area evaluation

Each player's score is the number of his stones on the board and the empty intersection points that are only enclosed by his stones.

Area valuation is also known as Chinese valuation and is used by Chinese, U.S., New Zealand, Ing, Simplified Ing rules. The great advantage of the area evaluation is the connection between the visual perception of the position at the end of the alternating drawing and the number of points. Another advantage is the direct deduction of the number of points from that position.

Area assessment with pass stones

Immediately before the evaluation, White passes last. For every pass during the game, the player pays one stone, which becomes a prisoner. Each player's score is the number of empty intersection points, which are only enclosed by his stones, and the prisoners of the opposing color. Prisoners are the stones that were struck during the game due to a lack of freedom, removed due to the agreement on removal or paid for when passing.

Area assessment with pass stones is used by US rules (which also allow area assessment as an alternative) and French rules and is equivalent to area assessment, i.e. H. the difference in points (not the absolute number) is the same with both assessment methods. There is also the advantage of being able to derive the number of points directly from the position at the end of the alternate drawing.

Traditional territory assessment

Each player's score is the number of empty intersection points, which are only enclosed by his stones, and the prisoners of the opposing color. Prisoners are the stones that were struck during the game for lack of freedom or that were removed due to the determination of status.

Traditional territory assessment is also known as Japanese assessment and is used by Japanese rules, Korean rules, and oral rules that are similar to them. A disadvantage of the traditional area evaluation are the intermediate steps required to determine the number of points: The status aspects are derived from the position at the end of the alternating drawing in a multi-stage process, which is based on the analysis of strategically perfect hypothetical alternating drawing, before the score is based on this can be derived.

Other reviews

There are other evaluations, such as the control area evaluation, but so far they have hardly played a role in practical application.

Counting

Each evaluation allows different counts. In all cases, the prerequisite for the evaluation is agreement on the status of all stones on the board. This results in the distribution of the empty grid points after the trapped stones have been removed. The counting of a player's score depends on the scoring method. The winner is the player with the higher number of points. A tie (in Japanese: Jigo) with the same number of points is possible.

Point-by-point counting for area evaluation

The grid points that score a player are counted with the finger on the board: 1, 2, 3, ...

This or an algorithmically comparable method is probably the most common type of counting for software. However, this method is lengthy and error-prone when playing a game without computer assistance.

Half-count for area evaluation

The half-count makes use of a simple consideration. The total number of all grid points does not change depending on the size of the playing field. With a 19x19 goban there are 361 grid points. At the end of a game, the number of neutral grid points is subtracted from this basic number. The remaining grid points count for either black or white. Therefore, it is sufficient to find out the score of only one player. If the number of points is greater than half of the counting grid points, this player has won. If it is smaller, the opponent has won.

Example: At the end of a game there is a neutral grid point. So the number of counting grid points is 361-1. Black has 184 counted points. Black wins with 4 half points, there ${\displaystyle \textstyle 184-{\frac {361-1}{2}}=4.}$

In order to make a comparison with the point-by-point counting and to subtract a possible Komi from the black number of points, the half points are doubled.

How the points of a player are counted depends on the rules. According to New Zealand rules, counting is point-by-point.

End position	Changed arrangement	Stones grouped

According to Chinese rules, black's points are counted. In the first step, the empty grid points of black are counted. It is irrelevant for the final total number of points whether a grid point is empty or occupied by a stone.

The arrangement of the empty grid points can therefore be changed until their number is a multiple of ten. Larger areas are preferably emptied and small areas are filled in. The boundaries of the changed areas do not have to be exclusively black, as long as it remains clear who the empty grid points belong to. The number of now empty grid points is noted (in the example this is 20).

In the next step, the white stones are removed from the board or pushed aside and the existing black stones are grouped into groups of 10. In this example black gets 23 points for his stones. The total score is 43.

The game was played on a 9x9 goban. The basic number of grid points is 81. There are no neutral points in the end position shown. The victory limit is therefore  = 40.5 points. Black wins with 2.5 half points or 5 full points. ${\displaystyle \textstyle {\frac {81}{2}}}$

Chinese half-count is used in conjunction with Chinese rules.

Ing fill-in count for area valuation

During the whole game, the number of black and white stones remains exactly 180 (there are special Ing cans for this). All pieces are placed on the board for counting : black pieces in a black area, white pieces in a white area, each rounded half of black and white pieces on empty intersections that are neither black nor white areas. Then mostly (unless the total number of points is exactly 0 or 1) a player, the loser, keeps stones left over, the loser stones, which are filled into the opponent's remaining area, consisting of winner intersections. This wins with the number of points of the empty winner intersections plus double the number of winner intersections filled with loser stones.

This works because an intersection point equally scores for a player, whether it is empty or filled with his stone, since each double-counting loser stone covers an empty intersection point of the opponent and at the same time cannot cover another intersection point of his own because the non-scoring intersection points be filled fairly, since the number of all stones is 1 less than the number of all intersection points and since the 1 remaining empty intersection point represents either a winner intersection point which is judged for the winner or an intersection point which is not judged for any player and which, because of an odd number of such non-judging intersection points half of which is left over.

Ing fill-in counting is used by Ing rules and partly together with Simplified Ing rules.

Japanese census for area assessment (Seichi)

Black Prison Stones are filled in black area, white Prison Stones in white area. Possibly. excess stones are kept next to the board. The remaining areas are then converted into forms that are traditionally considered to be easily countable, representing multiples of 10 if possible, otherwise 5. The number of points evaluating a player must remain constant. While maintaining this, stones can be transferred in order to meet the objective of the representation order. Then the points for each player are added up, the number of any surplus stones a player has to his account is subtracted and the difference between the two players is determined. This type of counting is called seichi.

Japanese counting is used in conjunction with Japanese rules, Korean rules, and oral rules similar to them.

Additional rules

In addition to rules specifically designed for tournaments, there are a few additional rules that also play a role outside of tournaments.

Compensation points

Black's suit advantage, who starts the game, can be offset by compensation points (in Japanese: Komi). At the moment, the usual values ​​for the 19 × 19 board vary from 6 to 7.5. (8 Komi for Ing rules with the extra stipulation that Black wins in the event of a tie, corresponds to 7.5 under other area valuation rules.) Integer values ​​enable a tie in the valuation - fractional values ​​prevent it. The Komi is assigned to White in the assessment and shifts the score accordingly. If a half count is used without subsequent doubling back into the full count, a half Komi should also be used, which is 3.75 in the Chinese Profi-Go, for example.

Compensation stones

If one player is significantly weaker than the other, he can receive compensation stones, also known as handicap, which he places on the board as black instead of his first move. There are two variants:

Free default: The default stones can be set at freely selected intersections.

Fixed guideline: The handicap stones are placed on a specific selection of the Hoshis (star points, specially marked on the board).

Go rules in Germany

Due to the historical development, go players in Germany traditionally orientate themselves on the Japanese game practice. Basically, the Japanese census (area evaluation) is common as well as fixed specifications in games with handicaps. Compared to the official Japanese rules of 1989, however, some deviations and simplifications have become commonplace. For example, an illegal move does not necessarily lead to the loss of the game, but is usually sanctioned less severely (conversion into a pass or simple withdrawal).

In tournament announcements there is often talk of the “Japanese rules that are common in Germany”. The details are given orally or are at the discretion of the respective tournament management.

Web links

Official regulations

• Chinese rules from 1988
• Ing rules from 1991
• Japanese rules from 1989 (currently valid)
• Korean rules (link invalid, March 14, 2017)
• New Zealand rules
• American rules
• Simplified Ing rules (used by the EGF)

Web links for those interested in rules

• Equivalence of area assessment and area assessment with pass stones
• Goregel page by Robert Jasiek
• Ikeda rules
• Commentary on the official Japanese rules from 1989
• Japanese Rules of 2003 (Model Set of Rules)
• Commentary on the 2003 Japanese rules
• Error in the rules of the 1979 World Amateur Go Championship
• New Amateur Japanese Rules (Model Rules)
• Tromp-Taylor rules - as brief and precise a set of rules as possible
• Go Rule Dialects (basic rule variations and historical development)
• Tutorial to learn the basics
• Draft for the writing of the Japanese rules customary in Germany