Japanese Rules

  Difficulty: Beginner   Keywords: Rules

The defining features of Japanese style rulesets are

  • Scoring is by surrounded territory plus dead or captured stones, called territory scoring (also see Japanese Counting). More specifically, Japanese rules use Traditional Territory Scoring, where territory depends on life and death.
  • Nothing in a seki counts, neither "territory" nor "dead" stones.
  • Suicide is disallowed.
  • Rare situations like triple ko can cause a game to be voided.
  • Resolving disputes about life and death or protective plays during scoring may require more than simply resuming play.

Compare with Chinese rules.

Official Rulesets:

Japanese Style Rulesets:

Commentaries:


Life and Death Rules

Because the Japanese rules make use of Traditional Territory Scoring, which penalizes plays in your own territory, they provide for resolving life and death questions at the end of the game without actual play.[1]

The 1949 Japanese rules, the first formally written Japanese ruleset, made first ad hoc attempts to define life, death, and territory. That and special rulings for peculiar shapes drew criticism.

The 1989 rules were an improvement in the sense that such cases are now decided by method. The drawback is that the method is not easy to understand. Besides the rules [ext] contradict traditional scoring even in basic shapes.

See Question About Japanese Scoring for some discussion and Bent Four In The Corner for a scarce but frequently cited example.


"Passing for ko"

If there is a necessity to clarify life and death after both players have passed, this is resolved by hypothetical play in which a ko ban on a particular ko may be lifted by a pass designating that ko.


See Discussion for more.


[1] There are territory rules that provide for resuming play in an encore to resolve life and death, such as Lasker-Maas rules, Ikeda Territory I Rules, and Spight rules. Play in the encore uses area scoring, in effect. This allows a player to capture dead stones without penalty.

Harleqin: It is also possible to use a "virtual" encore, restoring the end position afterwards. That way, you do not revert to area scoring but still have no need for a definition of life and death. I have devised such a ruleset: Einfache Gebietsregeln.


This is a copy of the living page "Japanese Rules" at Sensei's Library.
(OC) 2007 the Authors, published under the OpenContent License V1.0.
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