I just found out that there’s a un jeu de rôle médiéval-fantastique (medieval fantasy role-playing game) of the Dungeon comic by Sfar and Trondheim. The page for it is located at http://www.legrog.org/jeux/donjon-clefs-en-mains/donjon-clefs-en-mains-fr. The original publication in 2001 is pretty pricy ($80 or more) but they recently released it and it is much more reasonable. Buy it at Amazon.fr
If you haven’t read the Dungeon, go check them out — they’re great! You can order them from Amazon, but chances are your local library has copies. They are very popular.