The card game
- Game-Breaker: So-called "hat guessing" strategy. Rather than giving clues to convey information, hat guessing strategy assigns the actions what the other players should do depending on the type of clue given (meaning, that at least 10 different actions can be coded in a default variant, multiplied by the number of other players). This caused an official manual to add a rule that does not allow so-called 'empty clues'.
