Twenty years after popularizing role-play games and inspiring wanton fundamentalist paranoia, Dungeons & Dragons is finally a movie – a Wayans brother movie at that. Marlon plays Snails, who with his buddy Ridley (Justin Whalen, best known as the second Jimmy Olsen on “Lois & Clark: The New Adventures of Superman”) is a “practitioner of the larcenous arts” in the kingdom of Izmer. Their mission is to – deep breath – accompany a dwarf and a pretty supermodel magician to outrun an elf to guard a map to navigate a maze to steal a ruby to enter a vault to find a staff that will control the red dragons before an evil wizard (Jeremy Irons) can get it himself and usurp authority from a reform-minded young empress (Thora Birch, doing a heavily sedated impression of Natalie Portman…or maybe an impression of a heavily sedated Natalie Portman) who controls the white dragons and wants to give the patrician mages and plebian commoners equal rights. Whew. There are lots of quasi-mythical exposition, a low-rent Star Wars cantina sequence, characters who can’t decide whether to speak Kings James or Compton, and a villain (Bruce Payne, from Highlander: Endgame) who wears plutonium lipstick and talks like his armor has gotten bunched up somewhere below the sword belt. It all has about as much to do with the game D&D as it does with Parcheesi, and ends with an incongruously sudden dogfight among hordes of computer-generated dragons that was only affordable because the movie was shot in the Czech Republic. Beware of sequels, too. D+