Japanese 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).
- 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:
- Current official rules for professional play in Japan:
Nihon Ki-in 1989 rules
-
WAGC 1979 Rules
Japanese Style Rulesets:
- Interpretation:
Japanese 2003 Rules (Robert Jasiek, 2004)
-
New Amateur-Japanese Rules (Robert Jasiek, 2004)
- LJRG - Logical Japanese Rules of Go (Robert Pauli, 2002-2004)
-
Ikeda Territory Rules II (Ikeda Toshio, 1968-9, 1991)
- Spight rules
- Lasker-Maas rules (Edward Lasker, 1968?, Robert Maas, 1995)
Commentaries:
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Jasiek's 1997 Commentary on J1989 is outdated now.
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Commentary on the New Amateur-Japanese Rules
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On the rules of Go (Ikeda Toshio, 1968-9, 1991)
Life and Death Rules
Because the Japanese rules make use of Territory Scoring, which penalizes plays in your own territory, there needs to be some procedure for resolving life and death disputes at the end of the game without having to resume play. See Bent Four In The Corner for one example and Question About Japanese Scoring for some discussion.
The 1949 Japanese rules, the first formally written Japanese ruleset, resolved problematic situations with special rulings. However, the ad hoc character of those rulings 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, and still produces some unexpected and peculiar results.
In any case, actual disputes are very rare, and normally easily resolved.
"Passing for ko"
If there is a dispute after both players have passed, then the only solution may be for one player to ask for the game to resume - and this is valid in the rules - once the game is resumed it is done so with the other player moving first. A resumed game has the extra rule that one cannot recapture a ko before they pass. Thus, to give an example of these two rules:
At the end of the game there is a dispute, white asks for a resume, black accepts and moves. sooner or later white takes a ko, black passes (for ko) white moves elsewhere black takes the ko... then white must pass before they can retake the ko.
See Discussion for more.