I'm confused about score system's influence on strategy

Let’s only consider Chinese rule, which score is empty space you surrounded. Is it bad to place stone in my own territory for safety to prevent opponent taking chances, making alive within my territory, since for safety I give up some score. Should I allow my opponent to mess around in my territory a bit and only interfere when it’s absolutely necessary, like otherwise they would make alive? If so doesn’t the endgame become garbage time, each side just do the chore of trying to find some optimized way to force opponent to fill their own territory as much as possible? And try not to allow opponent to make alive within my own territory with as few stones as possible? That sounds really dull for me, and end game would last so long and boring. Is that the way it is, or I misunderstood something?


Under the Chinese rules (and other area scoring rules), your score is your territory + your alive stones, and this is counted after removing dead stones from the board. Thus, at the end of the game, it would not cost you any points to place additional stones inside of your territory (provided that you don’t completely fill in eyes, of course).

Under Japanese rules, which counts territory + captured stones, it does cost points to play extra moves inside of your own territory. If the opponent tries launching an invasion into your territory, and you need to play additional moves to kill that invasion, they are also effectively giving you compensation (in terms of captures) for the additional stones that you need to fill in order to kill that invasion. For example, if your opponent plays N moves into your territory, and you have to respond with N moves to kill that invasion, the N stones that you capture balances out against the N moves that you’ve played inside, resulting a net change of zero to the scores. Hence, hopeless invasions, if handled properly usually have no impact on the score. In some cases, an invasion should wind up dying in ko. In those cases, it may effectively cost N+1 moves to kill N stones (where the additional move is to resolve the ko), and thus an invasion could effectively steal a point away, even though it fails.

The tricky thing to keep in mind about Japanese rules is that one is not forced to completely play out the capture of dead stones. During the scoring phase, stones are ruled as dead if under correct, hypothetical play, they cannot avoid capture. Hence, if your opponent throws in a single, futile stone into your territory, and it has no hope of living, you don’t need to play any additional moves to demonstrate that it is dead, and they are instead just giving you points.

Note: under both rulesets, before the end of the game, it costs at least one point to place a needless stone inside of your own territory. Under Japanese rules, you are at least giving up a point of territory, and under Chinese rules, you are also at lease giving up a point of area (since that stone could have at least been played to claim some dame point). However, the score loss is usually even larger (for needless defense), since you are effectively passing your move, giving your opponent the opportunity to gain more elsewhere.


Under chinese rules you only give up score, when you could play outside of your territory (and therefore increase your territory), but you play inside instead. The lost opportunity is the reason for the lost points.

Yes, that works. If there is still unclaimed territory left, you can claim that territory while your opponent isn’t achieving anything inside your territory. In that case your opponent would be losing points, because they are losing opportunities on the outside.
If all the territories are claimed, you can pass or answer, it doesn’t make a difference, because the territory ownership doesn’t change.

Not really. If there are still unsettled areas left on the board, endgame is about efficiently settling those areas. As soon as the whole board is settled, players usually agree to end the game by passing. One player could go on and place meaningless stones to prolong the game, and that would become a dull ending indeed, but that’s not allowed on OGS (for the very reason that it is meaningless and a waste of time).

You don’t have to use as few stones as possible, if you don’t have anything else to play. Then you can use as many stones as you want under Chinese rules (just be careful to not fill your last two eyes, as @yebellz mentioned too).


@yebellz answer is nice answering why and how it works.

In short : play as you want in your territory under chinese rules it will not change the score

What is not allowed is for an experienced play who knows what they are doing to play meaningless moves on purpose with the express goal of boring their opponent to death.

If a player has any doubts and wants to try invading their opponent’s territory, that is completely allowed. If a player has any doubts and wants to add moves in their own territory to make sure there isn’t a weakness that the opponent could exploit, that is completely allowed too.


Well, no.

Play as you want in your territory under Chinese rules after all territory is decided and dame have been played, otherwise it will lose you a point, just like in Japanese rules.


Indeed. It’s sort of a persistent myth that under Chinese rules you can play moves in your own territory in the middle of the game without any negative effect on the net score.

I’d say there is no difference in tactics or strategy between Japanese rules and Chinese rules, except that near the end of a game under Chinese rules there can be some fight to play dame instead of connecting the last half point ko, and when there is a bent-4 in the corner in combination with unremovable ko threats.


Well obviously you have first to maximize your space. It’s just another debate. I simply mean that adding a move won’t change the score in itself.

If you consider newcomers who at whatever time during the game will add unnecessary stones inside some boundaries they will lose points under the japanese rules and not under the chinese. Of course if your opponent answer in some clever place instead you will lose more as 0 (chinese) or 1 (japanese). It’s not a myth just considering what happens. You play inside, your score at this time stay the same in chinese rules (as empty count the same as occupied) and you lose a point in japanese rule (only empty counts). I’m not talking about next move of your opponent (which can be from bad to good).

No, this is literally wrong.

If there is any undecided point or dame on the board, then you will lose a point under Chinese rules, since the point inside the territory converts 1 point of empty space owned by you to 1 point of living stone owned by you (=0 change to your score). If you’d play a move outside of your territory, you’d instead convert 1 point of empty space owned by nobody into 1 point of living stone owned by you (=+1 change to your score). The difference is +1 point for you (and of course any additional points your opponent might make with their move, but if there’s still any unsettled point left, you always lose 1 point by playing inside your territory, compared to the potential of playing anywhere else).

Under Japanese rules, the exact same happens for a different reason. If you play inside your territory, you convert 1 point of empty space owned by you to 1 point of living stone owned by you, but since only territory is counted, this means you remove 1 point from your score. If you instead play a move outside of your territory, you’d convert 1 point of empty space owned by nobody into 1 point of living stone owned by you, in the worst case keeping your score the same. The difference is again +1 point for you (and again any additional points your opponent might make with their move, but you always lose 1 point by playing inside your territory).

Only if the game is already finished does it not harm to play inside your own territory under Chinese rules.

So moral of the story is: don’t play inside your territory unless it’s absolutely necessary, regardless of ruleset. The only case where it cannot do harm to play inside your territory, is if the game is finished anyways.


Consider this position, Black to move:


White has 9 points + 6.5 komi = 15.5 points in total.
Black has 15 points in total.

If Black plays the last dame, Black will have 16 points and win the game. If Black plays inside the territory, Black will have 15 points, and White takes the last dame, thus Black will lose the game.


White has 2 points + 6.5 komi = 8.5 points in total.
Black has 9 points in total.

If Black plays the last dame, Black will have 9 points and win the game. If Black plays inside the territory, Black will have 8 points, and White takes the last dame (not changing the score) thus Black will lose the game.

The difference, thus, for Black playing inside their territory, is that Black loses a point in both rulesets.


So, the one-sentence-per-ruleset summary:

On average, a useless move in your territory is…

  • Japanese rules: 1 extra point worse than any useful move due to filling your territory.
  • Chinese rules: 1 extra point worse than any useful move due to not expanding the area covered by your stones by 1 point.

So the difference between moves and therefore strategy is identical in both, except for micro-level considerations in the parity of endgame moves and dame that a beginner shouldn’t care about, or if there are no more moves left to gain area, in which case the game should be over.


We are talking for beginners here. If the game is already finished but they don’t see it, putting a stone in your territory will lose you a point in japanese and nothing in chinese rules.

1 Like

Which is why Japanese rules are best for beginners to teach/learn when the game is over!

1 Like

Yep! That does affect things a bit. Hopefully it’s still instructive to teach beginners that the scoring methods are still almost the same. I’ve seen beginners otherwise think that there is a large effect on the score when there isn’t.

One could also still classify this as a difference that’s not worth fussing over at beginner level compared to learning how to kill/save whole groups and not dying everywhere. If the opponent responds with any move anywhere, then there’s still no difference between the rulesets. Only if the opponent passes (assuming passing is in fact correct), then the player did on net lose extra one point in one ruleset and not the other, but the fact that the opponent passed is a pretty clear hint after that. Unless you play move after move after move despite the opponent repeatedly passing and signaling every turn that you don’t need to defend further because they were never interested in attacking anyways, you only get another 1 or maaaybe 2 points of difference between the rules, which is not so big.

All of this becomes a big mess of course when the beginners are very new and don’t even know how to finish borders, etc. Often that’s the biggest hurdle. But that difficulty is also not unique to just one ruleset either.


I am not going into debates on teaching (or not teaching) and such.
Newcomers may just want to play, experiment and discover on their own and come with a question, not asking for deep theory.
I was just answering the OP in a short way.

Strongly disagree on the best being to learn by pain, adding difficulty.

Learning to not waste a move to connect something connected is not in the usual abilities of a newcomer, let’s proceed step by step.

Under chinese rules you can go to eat the stones, putting as many stones as needed for it. Show the reality on the board and not asking for abstraction.


Teaching beginners in my own way: i avoid even to mention that there are different rules, keeping it for later.

Note that no one here did mention that apparently the OP is confusing chinese and japanese rules, my feeling from how he describes his question.
Myth theory is out of sight here, not asking if he could play better moves, just if he fill his territory with stones he’s going to lose points.
Just answer the question for a newcomer.
So under chinese rules, the goal is maximize your space, doesn’t matter with stones or emptyness and under japanese (which he confuses with chinese), maximize the emptyness only. That last rule will make you lose points by putting stones inside, at the difference of the first. That’s the question, not if there is a myth in it.

You shouldn’t worry about your opponent messing in what you think it’s your territory. Kill his stones, that’s all. Your territory will remain yours. You add stones to kill but you get prisoners from him, so the difference of score will remain the same if you count the emptyness (japanese rule) as you will put the prisoners in his territory.

That’s clever thinking as the more you wait the more you gain points. Now it’s not necessary to wait (and risky at times) just a bonus. If you have already enough to win you can answer each of his moves directly.

Quickly, by the experience, players stop to play where they will surely die. As it doesn’t change the score and it’s like you said pretty useless and boring.
You can have a look on stronger players games to see how they agree.

Does it make the end-game long and boring?

Yes, if one player spends ages on invasions that the other players rightly perceives as clearly futile.

No, if there are sufficient weaknesses to give the invasion a chance — then it becomes exciting.

The former can happen in handicap games, but there the stronger player should usually be patient. It should not happen much between well-matched players, but it sometimes does if one player is a poor loser.

The latter may happen in a game so close that one player would rather risk being invaded than defend.

I think it is reasonable to invade if it is not clear to you that your opponent will be able to deal with it. Perhaps controversially, I think that includes cases where they are in time trouble: one should always keep a reserve of time to deal with this sort of thing, which is fairly easy on most time systems, and if you play with very tight times, then time management is intended to be part of the game!

1 Like