On many occasions characters will have to resort to bluffing their way out of (or into) a situation. They can lie, feign ignorance, drunkenness, forgetfulness, or whatever they like in order to achieve their end.
The gamesmaster should encourage players to come up with a plausible story for the bluff and should then make a test against the character's Fel to see if the bluff is successful. The player's yarn is really only required for colour and entertainment, but the GM may decide that a bluff is extremely unconvincing (or convincing) and modify the character's test accordingly.
A successful bluff will completely convince its victims, removing any shadow of doubt from their minds. An unconvincing bluff may arouse hostility; a failure by 40% or more is likely to provoke open violence.