One of the most remarkable aspects of Peter Jackson’s The Lord of the Rings trilogy is its faithfulness in spirit and detail to the J. R. R. Tolkien novels on which the films are based. Books and movies tell stories in vastly different ways, and one of their primary differences is length. Novels often tend to contain more information than a two- or three-hour movie can possibly cover, and short stories are frequently used as the basis for film adaptations instead. When a director chooses to turn a novel into a movie, he or she must often eliminate or de-emphasize important subplots. Clocking in at over nine hours, The Lord of the Rings trilogy is much longer than the usual feature film, but Tolkien’s trilogy, plus the related novels The Hobbit and The Silmarillion,is itself long, spanning thousands of pages. Jackson’s ability to capture the diversity and richness of Middle-earth’s lands and peoples is therefore a substantial achievement. Jackson is evidently a reverential reader of the original books and did not want to deviate too much from Tolkien’s vision. In a sense, Jackson’s faithfulness to the books was necessary for the trilogy’s success. Dedicated readers of The Lord of the Rings are the book world’s equivalent of Trekkies: they are archivists of obscure, trivial details, even protective of these details. If Jackson had disappointed them, he would have lost a crucial audience and perhaps even caused a public relations mess. Tolkien fans, however, generally love the films.

Despite Jackson’s careful dedication to the novels, some differences do exist between the books and the films. In order to turn thousands of pages into roughly nine hours of film, Jackson had to simplify the original story by eliminating or changing certain characters. For example, Tom Bombadil, a significant character in the novel version of The Fellowship of the Ring, is absent from the movies. As a hard-to-classify godlike creature, he may have required more explanation than a fast-paced film could make time for. Crucial scenes involving Bombadil are therefore missing, including one in which the four hobbits come across a cache of elf weapons, weapons that prove important when Merry uses an elf sword to slay the witch-king, which cannot be killed by a human, in The Return of the King. Jackson works around Bombadil, however, to get the same information across. He gives the hobbits their weapons more directly: Aragorn gives the hobbits a sack of weapons on the hill called Weathertop in The Fellowship of the Ring.

The book-to-movie adaptation also affects the elf princess Arwen, but instead of dropping out of the film altogether, she actually takes on the characteristics of two characters from the novel. Arwen appears in the novels but plays a less significant role than she does in the films. The movie Arwen is a combination of the novel Arwen and an elf warrior named Glorfindel. In the film version of The Fellowship of the Ring, Arwen rescues Frodo after he’s been stabbed by a wraith and whisks him safely on horseback to Rivendell, with the wraiths in close pursuit. By giving Arwen this role, which Glorfindel carries out in the novel, Jackson does much more than simplify his story: he portrays Arwen as a heroine. This rescue is our first impression of her, and her bravery and strength in this scene balance out the more subdued role of delicate princess that she plays later, as she idles in Rivendell wondering whether to choose a mortal or immortal life. Her courage in saving Frodo puts her in the same league as the warrior-princess Éowyn.

Despite these changes, the essence of Tolkien’s novels remains intact. Jackson’s decision to forgo the obscure, extra details that round out the author’s trilogy didn’t lessen the thematic and narrative meat of Tolkien’s work, and the conflation or elimination of characters from the novels ultimately does not change the story very much. The films and the novels are not interchangeable, but the films prove as faithful as they can be to the novels without testing the limits of viewers’ patience and attention.