The differences between J.R.R. Tolkien's book, The Return of the King, and the Peter Jackson movie screenplay of the same name are very difficult to document because of the substantial difference in plot sequence between them.
There are two major plot threads in this story that are presented very differently between the book and the screenplay. They are the exploits of Frodo and Sam on the road to Mordor and the adventures of the other characters in the lands of the West—mainly in Gondor.
Instead of separating the two major threads into two internal books as Tolkien did, the storylines are interweaved in the screenplay to keep up the pace and progress of each. In this article, these storylines are "unshuffled" into two subsections to make it more intelligible, but because the movie starts with Frodo and Sam, that is where we start here instead of the other way around as in the book. The differences between the movie and book are described here in considerable detail. The order is intended to be that of the movie, and it is also the intent that this article should eventually include all significant differences between them.
Frodo and Sam
- At the opening of this movie, the story is told of the finding of the Ruling Ring by Deagol and of his murder by Sméagol, who became Gollum. In the movie, the story was a prologue(all three movies have prologues). In the book, Gandalf told the story to Frodo while they were sitting in the comfort of Frodo's parlor at Bag End. (This is in The Fellowship of the Ring chapter 2, 'The Shadow of the Past'.)
- One of the most unaccountable changes in the story made by the screenplay is Frodo casting Sam away after Sam offers to carry the One Ring once they had reached the top of the Stairs of Cirith Ungol. This did not happen in the book. Frodo and Sam remained together and did not part until Frodo was taken into the Tower of Cirith Ungol.
- In the book, Gollum inadvertently destroys the One Ring when he loses his footing and falls into the Cracks of Doom after finally reclaiming his "precious" from Frodo. In the film, Frodo and Gollum struggle for control of the Ring, causing both of them to fall; Frodo grabs the side of the cliff, but Gollum falls into the lava with the Ring. The change was made because the producers felt that the original events were anticlimactic. Initially, they planned to have Frodo push Gollum off the cliff with the last of his willpower, but they rejected that idea because it looked too much like cold-blooded murder.
In the West
- In the confrontation with Saruman in the movie, Grima kills Saruman, who falls and is impaled on the spiked wheel of one of his machines. Grima is killed by an arrow shot by Legolas. In the book, Saruman survives to nearly the end of the story. He eventually takes up residence in Frodo's own home at Bag End, which had until then been occupied by Lobelia Sackville-Baggins, but after his ruffians are overcome by the hobbits, Saruman is turned out. Upon leaving, he kicked Grima, which pushed Grima's hatred over the top, and he slew Saruman on the threshold of Bag End. Grima was then slain by the hobbits. Because the Battle of Bywater and the Scouring of the Shire did not make it into the films, a means of killing off Saruman and Grima had to be devised, and it was done at Saruman's home at Orthanc instead of Frodo's home at Bag End.
- Beregond and his son Bergil were completely left out of the movie.
- In the book, Prince Imrahil of Dol Amroth comes to aid Minas Tirith during its siege. In the movie, there is no Dol Amroth force. Characters such as Hirluin, Forlong, and Duinhir are likewise omitted, with the film primarily focusing on warriors of Minas Tirith.
- Arwen briefly forsakes her promise to Aragorn and departs Rivendell on the westward journey. In the book, she remains true to him even to the point of making for him a token of hope of his coming victory - a jeweled banner that was to become the standard of his royal house.
- In the book, upon returning from the confrontation with Saruman, the sons of Elrond, Elladan and Elrohir, along with thirty of the Dúnedain led by Halbarad, met Aragorn and fought beside him as a special elite force for the remainder of the story. This included their being with him, Legolas, and Gimli when they took the Paths of the Dead. On their journey from Rivendell, they had brought with them a banner that had been made for Aragorn by Arwen in hope of his victory. In the movie, there was no such group of men. No sons of Elrond were ever mentioned, and no Dúnedain. The object that was brought from Rivendell was not a flag but the reforged sword of Isildur, and it was brought by Elrond himself.
- On their journey from their muster at Dunharrow to Minas Tirith, the Rohirrim, in the book, encountered Ghân-buri-Ghân, the leader of the Drúedain. It was from him that Théoden learned that the main road to the White City was held against them by the army of Mordor. The king was also told about a hidden road through the forest that would not only give them a covered approach to the city but would also place them near the walls of the city well inside the rearguard of the Orc army. In the movie, the Rohirrim simply go to Minas Tirith and show up there on the grasslands of the Pelennor. There is no Orc army on the road to avoid, and there are no forest people from which to receive aid. The messengers of Gonder with the Red Arrow are likewise absent from the film.
- In the book, Aragorn uses the Army of the Dead to take over the Umbar ships and crush a Corsair/Harad army at Pelargir. He then loads them with allies of Gondor led by Angbor, whom he brings to the Battle of Pelennor. In the movie, he brings the Army of the Dead itself, which brings a swift conclusion to the battle and avoids the need for Legolas to describe the battle in a flashback.
- In the movie, the conversation between Eowyn and the Witch King on the Fields of Pelennor is significantly changed from the book's version.
- In the movie, Meriadoc Brandybuck is immediately aware that it is Éowyn who takes him up on her horse. The book has him (and therefore the reader) unaware of who she is until the point of her revealing her identity to the Witch-king of Angmar. Preceding this, she goes by the name Dernhelm. This was changed because it would be impossible to have Miranda Otto portraying a man to deceive the audience.
- The Last Debate is significantly reduced - with Imrahil, Elladan and Elrohir absent, Legolas and Gimli were added to Eomer and Gandalf keep the numbers. Also, in the book Aragorn makes a point of avoiding entering the city to take up his kingship. In the film, he has no such qualms, with Gimli even reclining in the Steward's chair whilst they deliberate.
- In the movie, Merry fights at the battle at the Black Gates, whereas in the book, he is at the Houses of Healing, recovering from the Battle of the Pelennor Fields.
- Pippin does not slay a troll in the Battle of the Black Gate. Instead, Aragorn fights a losing battle with a large troll chieftain until the Ring's destruction ends the battle.
- Bilbo appears to have forgotten Frodo's quest in the film, where he asks about the Ring. In the book, this scene occurs but then Bilbo remembers that the purpose of Frodo's quest was indeed to destroy the Ring.
- Celeborn departs Middle-Earth for the Undying Lands at the conclusion of the film, along with Frodo, Bilbo, Gandalf, Elrond and Galadriel. In the books, he remains in Middle-Earth with his grandsons Elladan and Elrohir before departing some time in the Fourth Age.