Sound Superko

Sound superko bans the completion of any cycle that includes no passes. Completing one that does, ends the game. In most cases that will be the trivial cycle.

Note that the legality of a cycle does not depend on where it started. See Rules Beast 1 for a case where unsound superko variants fail.

To not only have a sound end but also a sound result, proceed as follows:

1. If the last move was not a pass, continue the cycle until it is.
2. Apply the regret clause of the repeated-pass rule, in other words, let the fool lose if the cycle was a foolish one.
3. If still undecided, score.

Note that a pass here offers the end and therefore can not be used as a ko threat. To instead have passes lift the ban, take the repeated-pass rule.

— Robert Pauli

P.J.T.: Could you please include in this page an indication of where this terminology originates and who uses it?

Robert Pauli: It's my invention.