> >> "Contains at least one vertical piece in your favorite color" is OK > >> if everyone is OK with player-specific metarules, and the favorite > >> colors of all players are well-known. > > > > No. Spock doesn't know players' favorite colors. You can > only base rules > > on objectively observable characteristics of koans. > > That's not a clear diagnosis. The actual problem is that > "*your*" favorite > color is illegal; Spock doesn't know who is the guesser at any given > moment! A rule has to come out the same for everybody. Ah, see, this is not how I understood the proposed rule. It appeared to me that the proposed rule was specific to the favorite of koan's builder, such that if Joe built the koan and it had his favorite (say, blue) it was marked differently than if Jan built it (whose favorite is yellow).