I’ve often used capture go (also known as atari go) to introduce new players to the game. The differences from normal go are as follows:
The game starts with a crosscut shape already in the middle of a 9x9 board.
Passing is not allowed.
The first player to capture a stone or a group of stones wins.
For new players, it’s good practice for recognizing atari and ladders. For experienced players, the game usually continues to where you would pass and count in a normal game of go. However, since passing is not allowed, you are then forced to play inside your own territory. The player with less territory will eventually be forced to fill in the eyes of one of their groups, at which point they will be captured and lose the game. In this way, the main strategy of the game becomes to surround territory, even though the rules don’t mention anything about territory!
My interest in capture go was reawakened recently by this app which made me realize that there is no need to start from a crosscut. This leads to much more variety in the opening, and I think a very interesting game even for experienced go players. It’s similar to go, but different in a few important ways: for example, see this problem. I’ve played a couple of games online in the app, but unfortunately it’s not very popular, so usually no one is online to play.
So if anyone is interested in playing this variant with me, just send me a challenge with “Capture go” in the title! Obviously capture go isn’t implemented on OGS, so we’ll have to follow the rules of not using the pass button and resigning if we get captured.
It seems like a very different game than regular go. Since it is impossible to capture many dead shapes without first throwing in (sacrificing) a stone, it becomes easier to live with outlandish invasions into settled territory.
Indeed! So if you want to make secure territory, you will have to be more conservative than in normal go (smaller extensions, playing more on the third line than the fourth, etc). An extreme example: I think you can invade under a 3-3 on the 2-2 point and live (or escape)
I like this example because some historical counting systems involved a “cut tax” of 2 points per group which was deducted from each player’s score. The rationale for this can be seen in the example game above - each group needs 2 eyes to live and that is why white wins - despite black having a greater area of the board.
Atari Go is great fun and it would be useful if this functionality could be added as a ruleset to OGS. It would be very useful for teaching beginners and is also a fun variant for 9 x 9 fans such as myself