In addition to making the films different from the book, some of PJ’s changes can influence the quality of the films even when considered purely as cinema. The book can be compared to a finely tuned machine in which each part plays a role and is dependent on other parts. When it starts to be changed the repercussions can be large. Below are some instances of those effects.
An idiot plot occurs when the plot of a story requires the characters to act like idiots in order for the plot to advance. This occurs a few times in PJ’s trilogy because of some his changes disrupted the fine-tuned nature of the story. For example: in Khazad-dum Gandalf dangled from the Bridge and let go of his own accord after starting to clamber up and in Minas Tirith the Witch-king does not finish off Gandalf when confronting him. In the book these are both explained: in Khazad-dum Gandalf falls into the chasm and yells at the Fellowship to flee, and in Minas Tirith the Witch-king has not all but defeated Gandalf when the horns of Rohan are heard.
In the films however, the actions of both Gandalf and the Witch-king are inexplicable save for “they had to do it because the characters were necessary later on, as per the book”. The filmmakers wanted to follow the book to the extent that Gandalf did not escape Moria nor die at the hand of the Witch-king, but because they made changes to the circumstances the result was that Gandalf and the Witch-king both look like fools.
Similarily, while the filmmakers had no problem with Faramir taking the hobbits to Osgiliath, they had to have Frodo and Sam go to Mordor for the Ring to be destroyed. The “turning point” in which Faramir lets the hobbits go is quite odd though, as any reasonable person would have concluded upon seeing Frodo attempt to surrender the Ring to the Nazgul that he was far too weak to carry the Ring and thus sent him to Minas Tirith even faster.
In The Two Towers we, along with Faramir, are shown a map of Middle-earth and in The Return of the King a similar map is used to show the hobbits’ journey home. Both maps are similar to the ones in the book, so it would seem that PJ left Tolkien’s geography intact. It is not so, however, as PJ made numerous changes to the geography of Middle-earth. Some of these changes cause other parts of the films to make very little sense.
- In the book the Glittering Caves behind Helm’s Deep are accessed from the ravine behind the Deeping Wall, whereas in the film they are accessed from the “Great Hall” inside the main keep of the Hornburg. Given this, the Deeping Wall has no defensive value and is a waste of manpower to defend.
- The southern terminus of the Paths of the Dead is within sight of Pelargir, eliminating probably hundreds of square miles of Gondor’s core area (and population). This area is shown on Faramir’s map though.
- Early in The Two Towers Legolas states that “the Uruks have turned northeast … they’re taking the hobbits to Isengard!” This contradicts the maps found in both the book and elsewhere in the films in which Isengard is clearly west of where the Uruks were at that point.
- The Elves of Lorien are able to reach Helm’s Deep ridiculously fast in The Two Towers – far, far faster than Aragorn, Legolas, and Gimli had.
These changes cause the geography to become nonsensical and damage the internal consistency of the trilogy.
There were two major instances of anachronisms – something placed into a time period in which it could not have existed or does not make any sense – in The Two Towers. The first is when a Rohir orders archers to “fire!” on the attacking Uruk-hai at Helm’s Deep. The order “fire” would mean nothing to a pre-gunpowder army and should have caused the Rohirrim to start looking around for the source of the blaze. The second is when, in the aftermath of the battle, Gimli asserts that his axe is embedded in an Uruk’s nervous system – a cringe-worthy use of a modern term in a pre-scientific era.