Japanese Rules Popularity

Commentary on the Japanese 1989 Rules is quite an amusing read on the topic.

(Even just the Preface and Conclusion)

Fortunately in practical terms these problems rarely present, and we appear to have a reasonable handle on how to manage them in the OGS context.


Robert Jasiek is a highly opinionated and very passionate student of the rules of go. His commentary on the Japanese rules actually spans 4 large, wordy, highly technical essays.

From his rules page discussing Japanese/Korean style rules:

You like difficulties? Read about the official ruleset then:

  • The official Japanese Rules require several commentaries: One, Two, Three, Four
  • There are also the old World Amateur Go Championship Rules but you should not get interested in them.
  • Korean rules are like Japanese rules with some superfluous extras.

I need to bookmark this for next time we have a Japanese Rules dispute :smiley: :wink:

(Which, as I mentioned, is remarkably rarely: generally, I think we all known and play to the OGS spirit of those rules).

I think they are actually very present, and I was referring to that in another thread.

For example in the diagram below (taken from your link) there are no points because both groups are seki according to the rules:

That addresses one point from this thread: in Japanese rules it is necessary to fill dame.

If I recall correctly, that exact example is used in part of the discussion about " Why Literal Application of the Rules Creates Nonsense".

(I guess I need to go back and refresh myself if that is not the case - can you point to where it is, there is so much!)

I think it is only theoretically necessary, due to nonsense determination of seki in some cases. For example, in Diagram 15 of the rules it says that you would need to fill in that dame, but as far as I can see it is quite clear that both groups are alive and have territory.

This nonsense hinges from this regrettably simplistic statement in the rules:

" " Stones which are alive but possess dame are said to be in " seki ."

I recall reading that even the original author regretted this. It is not in the spirit, nor even (as I understand it) reflective of how it is played live (though I am on shaky ground with having no experience there).

But certainly that is not how it is interpreted at OGS.

At OGS, no-one is required(*) to play at A in Diagram 15, and unless there’s something I’m missing, the black group in the above picture is alive (but I still can’t find that example in the commentary to check if I’m missing something).

(*) Note: I’m just one person stating an opinion and observation, not the official rule-maker of OGS. Because I"m a moderator, I do find myself having to make calls on these things, and that’s why I’m interested. So what I’m saying is reflective of how I would currently call it. But this is a discussion… if I’m wrong somehow - entirely possible and likely - then that just gets noted and fed back into future debate/decisions.

Right, we are not worried about the groups being alive, we are only worried about the scoring. Also, note that I said necessary, not required.

In the position in Diagram 15, the black and white groups are both alive, but in seki because of the dame at A , so neither side has any territory. A move at A is needed to make Black’s and White’s eyes into territory.

image <

So if you have black and don’t play A, then you cannot claim the 3 points surrounded by black. As for OGS, if the score estimator marks them as points, I should be able to unmark them.

I am not arguing whether it makes sense, I am just stating the Japanese rules. See the video shared by @smurph for a real life example.

Here is the real root of the matter.

We know that you will not be able to “just state” Japanese rules with any consistency or usefulness. You only have to read the “Preface” and “Conclusion” I linked to before to be convinced of this.

Therefore, there are two separate conversations:

  1. A theoretical one about the twists and turns of the Japanese rules.

  2. A practical one about “The Japanese rules at OGS”

I only just learned in the last week how far apart these two conversations are. Having learned that, I find the first topic fascinating in the same way that the Antarctic is fascinating.

The second topic is the one that seems to matter more, and I’m keen to be on top of.


Allow me to correct you. The paragraph I quoted is directly taken from the rules and crystal clear. Let’s not do a hasty generalization.

Are you implying that they are different from the official Japanese rules? Then it might be good timing to post a link, because so far the whole conversation and references have been to the official rules.

Yes, we should definitely replace “Japanese Ruleset” with the more appropriate “Pragmatic Territory Scoring Doctrine” or its abbreviation.

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Let’s be clear about this.

The official Japanese rules are written here.

It is copiously clear, both in that document and the associated commentary that literal interpretation of these rules is nonsense.

Therefore any group or organisation wanting a practical implementation has to make sensible interpretations.

It is a red-herring to ask “are the Japanese rules different at OGS”. The answer is "“mu”).

There are the Japanese rules.

There is how we interpret them at OGS.


Again, where?

Here, in discussions, and as we make decisions when we are called to do that.

Much like real law: there are laws written, then they are tested in cases, and those cases used in precedents as examples of how the law is interpretted. This doesn’t mean there is “another law”, it just means that laws are always subject to interpretation.

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I find that analogy to legal case law to be quite troubling. There is a huge difference between a system of laws intended to govern society versus those intended govern an abstract board game.

I don’t think a well formed set of rules for go should leave ambiguities that are open to interpretation, nor require complex analysis and lengthy discussions to determine the correct, intended judgments.

If the intent is to closely resemble the official Japanese rules/conventions, then I think it seems a bit arbitrary and error-prone to have the “Japanese rules on OGS” only exist in discussions and decisions as they are made. I hoped there would have been a better system for implementing Japanese-style rules on OGS.


You are welcome to suggest one. I mean that earnestly. If the community reviewed it and agreed to it, it could well be a useful resource for moderating.

The commentary we’ve all read tells me that this would be non-trivial.

It may also bring the (silly, but still real) risk that OGS would then become known for having “it’s own” Japanese rules, as opposed to being like everyone else and just interpretting the “real” rules.

The upside is you might also become famous as the person who succeded in writing a usable Japanese ruleset for online go servers…

I realize the thread is about popularity of Japanese rules, not their efficacy. But I’d like to offer an opinion, from the perspective of someone who still exists more or less on the fringes of Go culture.

Perhaps the Japanese rules are intuitive for players more familiar with the game. For me this discussion is a turn-off.

If I had any desire to discuss at length the particulars of a rule book, I’d have taken up Euro games in earnest.

Do the Chinese rules have as many caveats?

Please don’t take this as snotty. I still like all you guys. :grin:

You shouldn’t be put off by the technical abstract hypothetical rules debate about Japenese.

All this stuff almost never surfaces in actual games.

I don’t know why it is, but I find it much easier to count the empty spaces + prisoners than worry about stones and dame, so Japanese seems much easier.

(I also have this feeling that players are less inclined to fill the dame under Japanese, which is a big plus in my book, since I play correspondence).

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No, the Chinese (and other area scoring) rules are much simpler, since life and death disputes can be settled by playing it out, rather than adjudicating things by determining the hypothetical best play out while imposing a modified ko rule.

Ultimately, the strategy and outcome under Chinese and Japanese rules are almost always the same. The biggest differences occur in some rare edge cases, but in those cases, I think the Chinese rules have the clear advantage of being easier to adjudicate.

Several people have proposed “Japanese Style Rule Sets”.

Jasiek’s “2003” rules attempt to accurately capture (in a more precisely defined way) how the official 1989 rules are applied in Japan. These 2003 rules are still very complex (perhaps more so, since there are a lot technical definitions to slog through), and I personally cannot attest to the quality of the effort, since I have not tried to fully understand it. Maybe this one can be ruled out if you are concerned about the complexity for effective moderation.

Several other proposals attempt to simplify the rules, perhaps making them a bit easier to apply and consistently moderate. There are trade offs between simplicity and how closely one tries to adhere to the official Japanese rules. Each of these proposals would have to be carefully studied to weigh their merits. I cannot make a suggestion, since I have not thoroughly studied them.

It seems that you say above that OGS is currently already using “it’s own” Japanese rules, since you expressed that there is a significant difference versus what is written. Adopting a new interpretation of the rules is essentially adopting our “own” set of rules, which I don’t think is necessarily a bad thing.

I think consistency, transparency, and clarity are more important. That’s why I object to a practical application of the rules that functionally exists as a series of discussions and decisions. I would prefer to see a clear, written standard as the authoritative rules, even if that document is not the 1989 text (which maybe it shouldn’t be).

A comment like this seems a bit sarcastic, despite expressing sincerity earlier. I have no interest in inventing yet another Japanese-style rules proposal, nor any illusions about my ability to do so.

Counting the difference in the number of prisoners (black’s captures minus white’s captures) is a quick way to determine the difference in the number of stones on the board (black stones minus white stones). Just add one if black was the last to make a move. If the players have made an unequal number of passes, add that difference as well.


@GreenAsJade I don’t share that feeling/experience. As already said you don’t have to play dame in Chinese too. Well I play them most of the time whatever. Each rule has own drawbacks, I feel Chinese to be more friendly/understandable for lower level players, and Japanese more esthetic after as long as nothing troublesome happens. (It does happen, just consider how often the case of L group in the corner show itself).

I share the guess that Japanese rule is most used because it’s the rule by default and because weiqi was introduced by Japan to westerners in its history.

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To return to the original question, SanDiego is correct. Go was introduced to the West via Japan. Also, go was most developed culturally and competitively for centuries in Japan. Korea recently took over as the reigning champion of the go/baduk world, but Korean rules are identical to Japanese rules. (It remains to be seen as China attempts to take the lead whether the world might begin to prefer Chinese rules.)

So for all these historical reasons, Japanese rules (and terms) have always been the default in the Western world.


The Japanese rules technically imply that dame need to be filled in order to prevent “normal” living groups from being consider in seki, which would nullify their territory.

Filling dame appears to be the practice in at least some formal, professional situations (as seen in the video that @smurph linked above). Note that filling the dame also aids with their counting procedure, making it easier to rearrange territory into rectangular regions without worrying about accidentally counting dame.

Of course, in common practice, especially in many informal and internet games, players using Japanese rules will often leave some dame unfilled, yet don’t assert that all adjacent stones are in seki.

The rules would allow a player to assert seki (and nullify associated territory), but it also allows their opponent to resume the game and fill in dame to remove the grounds for that assertion. Hence, actually making such claims (perhaps in a futile attempt to win a lost game) would seem ridiculous and even insulting.

So are players technically violating the Japanese rules by not filling dame, while regarding adjacent stones as not in seki? Perhaps, but not in a manner that changes the result of the game, and only as an informal way to avoid extra moves. I view it as the players basically coming to the mutual understanding that they won’t waste time with actually playing inconsequential stones, but still pretend that they have filled the dame for the purposes of determining life/death/seki and counting the score.

However one views this practice, I think it is way too strong to say that it is evidence that the written 1989 Japanese rules are nonsense. The rules are not rendered invalid simply for not codifying an informal shortcut.

As another example, in the video mentioned above, we also see professional players rearranging stones (while even breaking border lines!) in order to make manual counting easier. This method is not technically sanctioned by the rules (even if you allow some rearranging, breaking the borders would clearly render territory invalid), but no one seems to object since it is understood that they are not really changing the score.

To be clear, I do think that there are significant drawbacks to the Japanese rules (mainly revolving around the complexity of life/death adjudication), but I don’t think that dame being left unfilled is a source for substantial criticism.