"A Game of Wagers, Wine, and Competitive Lying"
Players, preferably gentlemen from good families, challenge one another to recount, as outlandishly as possible, their many exploits, occasionally wagering against the narrator's ability to incorporate complicating circumstances into the tale.
From the back of the book:
"The Extraordinary Adventures of Baron Munchausen contains a full set of rules, background, more than two hundred adventures ready to be played, a revolutionary system of mechanics that does away with dice or cards and uses money and fine wine instead, two combat systems ('duelling' and 'duelling for cowards'), quick-start rules and a great many insults against the inhabitants of various nations, but principally the French. This game can be learned in under five minutes, requires no GM or preparation, and takes about an hour to play. You will require pencil, paper, imagination, a manservant, money, a selection of fine wines, noble blood, a sense of flamboyance, and at least one attractive member of the opposite sex (optional)."
Also listed on BoardGameGeek as The Extraordinary Adventures of Baron Munchausen