Well, first off it would be a Hard R movie with a tag line of "this movie is not for kids" (not that this would matter in the '80s)
A Dragonlance Cinematic Universe...ohhh. Or a Forgotten Realms Cinematic universe. Denzel as Drizzit, Dolph as Wulfgar, Danny Devito as Breunnar, Warwick Davis as Regius , Sharon Stone as Cartti-Bree, Seven Seagul as Zakeferin, Chevy Chase as Arkell with EPIC piratical effects and stop motion animation and models the size of warehouses.
And I'd do the beyond crazy cameo of Gary Gygax, Bob Salavadore and Ed Greenwood playing dice in Ten Towns.
And a hard heavy metal sound track, with Weird Al doing an iconic custom song of "Forgot my Realms" "Where do my dice roll now?" and "It's D&D....Dinomight! D and D! Hey hey!"