The movie version of The Lord of The Rings is quite different from the book version of The Lord of The Rings, but they’re both very much The Lord of The Rings. It’s the same story, and the movie does an incredible job at adapting the book by not adapting the book.
Let me explain.
Adapting the book means taking the novel and making it into a movie. Sometimes you have to change the plot to do this, and, sure, that is what’s done with The Lord of The Rings. There’s a lot in the books that’s not in the movies. The Old Forest and Tom Bombadil, the romance between Eowyn and Faramir, the Scouring of The Shire. But there’s also a lot in the movies that weren’t in the books. Arwen saving Frodo from the Nazgûl, Pippin lighting the beacon, Sam’s monologue about the stories that really mattered. Usual adaption stuff that you do to make a book work as a novel.
But the movie manages to capture the soul of the book and not just the plot. Now, it’s been around fifteen years since I watched the behind-the-scenes, but I have an idea. Rather than taking the novel at its face, it seems they first stripped the story to its spine and worked out from there.
At its core, The Lord of The Rings is about a group of Hobbits and a king who save Middle-earth from evil. It’s about how hope and people choosing to press on in the face of despair. And it’s about a Ring and the defeat of its Lord. From there, it’s a matter of rebuilding the plot with key moments as markers of the way, useful in how it serves the story’s spine and broadest beats. Helm’s Deep stays in, as it shows Aragorn and the Men of Rohan at their weakest, and yet choosing to fight based on a glimmer of hope. Frodo and Sam’s meeting with Faramir can work, but the movie reworks it to not only offer another obstacle for Frodo and Sam to surmount (pacing!) and to show Faramir at first choosing the temptation of the Ring before choosing instead to hope in their mission (theme!). Everything in the movie is in there with the greatest of intention: serving that narrative spine.
It’s not the easiest way to adapt a movie. It’s far more straightforward to just cut out what doesn’t work and add things to stitch it together (the Harry Potter adaptions), completely change almost all of it (The Iron Giant), or even just adapt the book to the letter (Villeneuve’s Dune). Those ways work well enough, sure, but none quite capture the soul of the original like The Lord of The Rings. And I’m pretty sure it’s because rather than just trying to adapt it, they rewrote the whole dang thing.