Punigo vs. regular Go
Punigo's rules are based on a way of playing Go called “Jungo”. Jungo was devised by professional player O Meien 9-dan (Wang Ming-wan) as a way for newcomers to start playing Go.
What stays the same
How you place stones, how you capture, where you cannot play, and ko (you can't immediately recapture in a back-and-forth single-stone capture) are all almost the same as in regular Go. Ideas like atari, eyes, and life and death carry over unchanged.
What differs: what you count
| What is counted | How the game ends | |
|---|---|---|
| Punigo (Jungo) | Stones on the board | Fill your territory with your own stones, then both players pass |
| Japanese rules | Territory (surrounded empty points) and captured stones (prisoners) | The game ends once the borders are filled. Dead stones are removed and territory is counted |
| Chinese rules | Stones on the board and territory | The game ends once the borders are filled. Living stones and the territory they surround are counted |
In regular Go, the empty points you surround (territory) count toward your score, so you never need to fill your own territory with stones. Jungo does not count empty points, so you fill your territory with your own stones at the end.
Count a board that has been filled in this way and you get almost the same result as Chinese counting. The only difference is the empty points left as eyes. Because every living group needs eyes, having more groups costs you more, which is a feature unique to Jungo (see “Tips for 7×7 and 9×9”).
Why count only stones?
- Easy counting: when the game is over, you just count the stones on the board. You know who won without learning how to count territory or how to remove dead stones.
- Playing it out settles everything: in regular Go, both players have to agree at the end that certain stones are already dead. In Jungo, stones that can be captured are actually captured by playing on, so there is nothing to disagree about.
- The key idea comes naturally: filling your territory at the end lets you experience for yourself that a group without two eyes gets captured.
Moving on to 19×19
Everything you learned in Punigo (atari, escaping, eyes) is just as useful in regular 19×19 Go. When you move on, the main new things to learn are:
- Counting territory (don't fill it): surrounded empty points score. Under Japanese rules, every stone you place inside your own territory costs you a point, so unlearn the Jungo habit of filling in at the end.
- Judging dead stones: stones that cannot be saved are removed after the game and then the board is counted.
A good first step is to play a game of regular Go on a 9×9 board (Punigo only offers Jungo rules, so use another Go app or a Go club). With the same board size, you can focus on just the difference in counting.