Why are Dungeons and Dragons (D&D) movies so bad?
First, because they have not portrayed an original plot, and second they have tried to represent D&D play-rules instead of showing an exciting adventure. Just read one of the close to 100 novels based on D&D to find a good script for a movie.
In Dungeons and Dragons . Jeremy Irons appeared as the bad guy, a crazy wizard that wants to get rid of red dragons and get political control. We have to add a teenage princess that goes bananas and wants to promote democracy in the realm! Democracy in a Dungeons & Dragons world? What’s next? Human rights for goblins? Animal rights for carrion crawlers? Freedom of speech for druids and sorcerers?
It’s indeed a boring, boring movie, but when you add an atmosphere copied not from Tolkien, but from Star Wars Episode I: The Phantom Menace  it’s an insult to the intelligence of the viewer: a duel of two metal swords that for some strange reason have red and blue gleaming lights, a girly princess, dressed and acting as Queen Amidala speaking to an assembly about democracy, and an evil wizard mimicking Palpatine in speech and gesture. Finally, there’s a bad taste inclusion: a black young guy acting and speaking with the stereotype of the perfect African-American teenage jerk, named Snails and being, yes, a thief! I’m not sensible about racist stereotypes to have a laugh in the movies, but Star Wars influences and a making fun of black people in a D&D movie is simply bull-shit!
The second movie was produced five years later: D&D Wrath of the Dragon God . This time instead of copying from other movies the producers decided to create a movie based on the canonical classes, races, spells, limitations, and usages of classic and updated D&D. Unfortunately they forgot to throw in an interesting plot.
If you want to have a nice evening do yourself a favor and don’t watch these movies, play D&D instead.