Ko at the end of the game: Please help [does pass remove ko-rules on OGS?]

My game vs ded_obed ends in a ko

He can’t take on a1, so he passes.
I pass too.

We don’t agree about the counting of points.

Suddenly ded_obed plays a1. However this
should be an illegal move!!! Since it is the
very same position and an illegal ko move.
I mean, my pass didn’t chance the board

Please help.

Thanks beforehand.


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What an interesting position you two have created!
First things first you should not have passed if the board is not settled. The position is not resolved, one of the two groups is going to die. Instead white should have approached E4 or F4 (to try and capture). But even then I am afraid white would lose this fight as he has no ko threats and black will just take back the original ko and then eat the rest. Based on my quick glance I am afraid white had no way of winning the fight after the ko has started.

Regardless of the game outcome, my understanding of Chinese, Japanese, and AGA rules is that shouldn’t be allowed. Black would have to play elsewhere before taking the ko.

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Well it is kind of a special case. Problem is that it should not even have come to this. Both players should not pass before the situation was resolved. Common sense dictates not to end a game when there is a life or death ko still unresolved…

Normally you would even fill dames before passing (esp. in Chinese rules) Problem is white cannot fill the ko to end it, for he would die immediately. Yes, technically black should have probably played elswere instead of passing (just to make it simpler, he had all the right to pass…) does not really matter where, F7 feels like an obvious option. But black could argue that he considered the white group dead. When white disproved his claim the game was resumed and black wants to show he/she can kill it (And as far as I can see he/she is right). Even if white played first it would not have mattered (again as far as I can see). I therefore see nothing wrong with black’s behaviour. White would have lost either way. It’s just that they made it more complicated by passing too soon.

@kjavl @rowan
the japanese ruleset explicitly allows recapturing ko after passing.

the ko in the game isnt a real ko in the first place, since white cant actually win it (by filling after the capture, or capturing blacks group).


Ah, okay. So many exceptions. Isn’t it still a ko though? A ko that white can’t win unless black’s brain falls out, sure, but if black doesn’t respond for two moves after white takes they can be captured.

You’re not allowed to play into a ko in the turn after it was taken.
If you pass in your turn, it was still your turn. It is no longer the turn after it was taken. Seems pretty clear to me (unless you decide that taking a pass is not taking your turn, but that interpretation creates problems :slight_smile: )

AGA and Chinese have superko rules, though. Japanese rules seem to be as you say.

youre right of course :slight_smile:. but under normal circumstances, this ko cannot be won by white. black needs to stop playing xD.

i just meant that even if white has (theoretically) more ko threats on the board than black, she can never win it because connecting it would be self atari.

EDIT: oops… i was a bit hasty there ;). white can make this into a worthwhile ko if she ataris the black group after blacks first pass.

the dispute here is about two things.

  1. Do two passes end the game? if so then a pass cant be a ko threat, since if your opponent passes too, you dont get to play again. thats why ko can be taken after two passes, so they dont stay unresolved.

  2. I dont know about all the rules, but some are not about prohibiting immediate recapture. instead they state, that the board position has to change before recapture is allowed, which a pass doesnt.

Thank you all for the different replies of all of yours.

It’s a difficult question I issued, but it is definitely worth
to discuss, although the ‘definite answer’ isn’t to give
easily, if at all.

When (and if) this very same issue will occur in another one
of my (of others’) games, I (and others) feel free and satisfied
to revisit this topic as there has has been said a lot of different
thoughtful things.

I want to thank you all for your contributions to this interesting topic!