Keima Go
Keima Go
Keima Go is played like normal go, with two exceptions:
- you have to place two stones instead of just one on each turn you don't pass
- and both stones have to form a keima.
Since each stone captures on its own, one stone may clear the intersection for the other. Neither of them, however, may commit suicide.
After two[1] passes in a row, the result is determined via area scoring. Since this excludes free removal of "dead" stones, and capturing may turn out impossible, quite some "territory" may end spoiled. Considering this, komi is only 2. Usually a 9x9 board is used.
Cycles with a periodicity of more than two moves void a game, those with a periodicity of exactly two moves (ko) are banned, as usual. The latter, however, can't happen on standard MxN boards.
See also http://www.hannover-go.de/Keima-Go/Keima-Go.html (German).
[1] Variation: three passes, and passes clear ko bans.