I finally got a copy of Coup at Gen Con, not a new game but one I enjoy. Coup is a game of bluffing, deduction, and assassination. You have two hidden cards that give you abilities, but feel free to lie about what two they are and use whatever abilities you like. If you are called on the bluff, you lose a card; if you are challenged but were telling the truth, your challenger loses a card.
Playing a bit at Gen Con, I found that I am better at telling the truth unbelievably than lying believably. This is a drawback for Mafia/Werewolf, but it works brilliantly in Coup. If I never bluff, I have no tells that indicate I am bluffing. But he could not really be telling the truth every time in a bluffing game, could he? Especially when you get a really unlikely draw, like two of the same card, or when you use the Ambassador to pick an unlikely pair of cards rather than a powerful pair.
And if I can train everyone to believe that I never bluff, I have free reign to start bluffing…