The astoundingly bad first film (Dungeons and Dragons, most notable for Jeremy Irons' absurd performance) assumes basically no familiarity at all, and indeed was likely perceived by the hardcore D&D nerds to be nothing so much as a soulless cash-in, borrowing franchise elements but not their context. See also either one of the J.J. Treks.
The far lower-budgeted, but surprisingly decent, second film (Dungeons and Dragons: Wrath of the Dragon God) actually resembles many D&D campaigns in tone, rather than resembling all the worst things about The Phantom Menace as its predecessor did. Yet it doesn't assume much D&D knowledge of its audience. There's even a scene where a character explains the difference between arcane and divine magic, which would've seemed insulting to the hardcore fans if they hadn't already seen the first movie and thereby known true insult.








