Hmm ... in my current playround my Wizard has a Charisma up to 7 (or even 8) and still can loose such a mini game !
THAT I find very weird ! With such a high charisma I like to win all mini games ! I've taken the effort to put many points in Charisma, so ...
But on this very moment I'm thinking about starting a New Game and forget about Charisma

!