A film adaptation of Eragon was made in 2006, starring Jeremy Irons, Ed Speelers, and John Malkovitch. Like The Golden Compass, it was very loosely based on the book. A video game based off the movie was released a month in advance. Currently there are no plans for sequels, although several petitions to remake the film have since been created.
The movie uses the following tropes:
Actor Allusion: This isn't the only time Jeremy Irons played a character who killed one of the main character's fathers. However, given what that father was like, not to mention what he did to his dragon, Brom pretty much had a very good reason for doing so. He's also seems to be looking to bring about the death of the king, again.
Adaptational Badass: In the book, Eragon only kills Durza with a distraction from Arya and Saphira giving him the opening to stab Durza's heart. Here, it's pretty much all him.
Badass: Murtagh. He kills an attacking urgal while unarmed and in a cage, breaks free, dives right into the battle with no armor, and quickly begins cutting down urgals left and right just with whatever weapon he can get his hands on.
Bling of War: Unlike in the books, where the Varden are portrayed as having barely enough money to finance themselves, in the movie even the lowliest soldier looks like they're trying to blind the Urgals with their collective fabulousness.
Dark Is Evil: As if we needed more clues, Galbatorix's dragon is jet-black.
Early-Bird Cameo: This film was the first time Galbatorix had ever physically appeared in the entire franchise. The same goes for his dragon
Enforced Method Acting: Eragon's surprise when Brom comes up behind him when Eragon is looking through Brom's books for information about dragons.
The Ra'zac are very different to their book counterparts. In the book they are described as tall, cloaked, pale and skeletal vulture-like creatures. In the film they look like ninjas with a maggot problem.
Dragons always had the "leather wings" descriptor somewhere near them in the books. Why does Saphira have feathered wings?
The Urgals in the Book are described as tall, large, grey-skinned Horned Humanoids. In the movie, they are pretty much Tolkien-esque Orcs with white and red skin, and have no horn.
In the book, Eragon and Arya are described as brown-haired and dark-haired, respectively. In the movie, both of them are blond.
Justified with Galbatorix: in the novels, he doesn't show up in person until the final book, which had not been published yet at the time. Then again, the fact that he shows up in the movie at all is a pretty significant difference from the book...
Angela bears little ressemblance to her book counterpart, being portrayed as a mystic fortuneteller rather than an eccentric Genius Ditz herbalist.
Ironic Echo: Durza mentioned that he expected more when he first encounters Eragon. Eragon shot that phrase back at Durza shortly after impaling him midair in the heart.
Oh Crap: When Sloan learns that Eragon got the "stone" (actually a Dragon Egg) in the Spine, he's shocked and hurriedly gives back the stone to Eragon, denies its sale, and states he shouldn't have brought it here. It's not clear why he does so in the film, though the book explains that his wife died in the Spine, and he's hated anything associated with it ever since.
Orcus on His Throne: It says a lot about Galbatorix that his appearance in this film is actually an addition to his appearances in the books.
Our Elves Are Better: Averted. Galbatorix mentions elves outside his empire, but it's not clear whether or not Arya is even supposed to be an elf in the movie.
Shout-Out: Brom's "I've seen things you can't image" line is a shout-out to Blade Runner, according to the director.
Stillborn Franchise: The movie was a critical failure and a financial disappointment. It also made it impossible to create a film of the second book due to discontinuity created by the first film, not to mention the number of ignored characters that would need to be introduced.
The Stool Pigeon: Like in the book, Sloan the butcher ends up squealing to the Razac about Eragon's possession of the egg. Unlike the book, however, the reason he did so was heavily implied to be under the Lacerated Larry type (ie, he was tortured into giving the information).