Continuity mistake: When Gollum and Sam and Frodo are by the river and Sam and Frodo are talking about Gollum. Frodo turns around and yells something like, "What do you know about it?" When he yells this, he and Sam's faces are a few inches apart. When it cuts to both of them, they are about a foot apart.
Deliberate mistake: First there's a shot of Saruman as he communicates with Sauron using the palantir, then a shot of Barad-dur. Next we see the Orcs at Orthanc pulling down trees and a shot of a tree falling into the cavern below. In FotR, just after Gandalf catches the moth atop Orthanc, we see a shot of a tree falling into the cavern down below. These are the exact same shot, only it's been flipped in this movie. (00:20:00)Super Grover
Revealing mistake: When Gandalf, Aragorn, Theoden, Legolas and Gimli all ride up the hill on horses towards the end, there is a man on a horse on the left of the screen. Who is he and why is he there? He's Éomer's body double (Karl Urban was unavailable) and at some stage they were going to put Éomer's head on him digitally, but they never got around to it. Director's commentary, extended DVD. (01:43:05)Super Grover
Continuity mistake: Legolas says, "Look at them. They're frightened. I can see it in their eyes." In the next wide shot, we see Aragorn's back, men all around, and behind him, to the right, stands Dan Hennah, with wavy, grey hair, in his cameo. In the following close-up, we see Dan Hennah again, standing to Aragorn's left. We also see Alan Lee's cameo, whereas, in the wide shot, Alan's character is not there. (00:53:10)Super Grover
Continuity mistake: At Henneth Annun, Faramir who is alone with Frodo and Sam, walks towards Frodo with his sword pointed at him. Behind Faramir, are many spears leaning against the wall. Then there's a shot of Frodo. In the very next shot there are fewer spears behind Faramir, and they are lined up very differently against the wall too. They are alone, and no one touched the spears. (00:41:50)Super Grover
Continuity mistake: As Gamling and Hama ride past Aragorn and Éowyn, a snowy high mountain range can be seen right behind them. As they are riding past Legolas' view, over Legolas' head, another greener mountain range is right behind them. These shots were filmed at different locations. (00:08:15)Super Grover
Deliberate mistake: In two scenes in particular, Legolas is letting loose his arrow with his left hand, because of shot flipping. When he kills the Warg approaching Gimli and when Legolas severs the rope, causing the tall ladder to collapse. The ladder shots of Legolas were put together later during editing, because Peter J. wanted an extra 'hero' shot of Legolas at Helm's Deep. They took the same shots of Legolas trying to take out the Berserker Uruk-hai and flipped it to specifically fit the later scene of the ladders going up. Commentary, extended DVD. (01:08:55 - 01:17:30)Super Grover
Continuity mistake: As this scene opens with an Uruk's body being dropped to the ground, the camera pans out to show Legolas and behind Gimli to his left, is a large rock. In the view from the front, now there is a dead Uruk sitting up against the same rock, where there was none before. He's dead, so he didn't move there between shots. Extended DVD. (01:38:50 - 01:42:55)Super Grover
Continuity mistake: Just after Sam's speech in Osgiliath, the first shot of Faramir shows several men talking and eating, with a background of decorative stonework and a broken arch on Faramir's right. After the shot of Frodo and Sam, we see the shot of Faramir kneeling. Behind him, we now see different stonework and a squad of men charging forward as if to battle. In the next shot of Faramir, still kneeling, we see soldiers walking and milling around in front of the original background. (01:37:15)
Continuity mistake: When Frodo and Sam are down below, near the Black Gate, wanting to run in, but Gollum is convincing Frodo not to, Frodo's pants have a couple of holes at the left knee. Later, when Gollum dives for the fish in the rocky stream, Frodo's pants don't have the holes at the left knee, as seen when he's walking with Sam. Frodo did not change his pants, and this is before they have spent the night, which is the scene right after this one. (01:06:00 - 01:36:55)Super Grover
Revealing mistake: When the Uruk-hai are running through the rock canyon while carrying the Hobbits, the Uruk with the painted white hand on his face holds up his right fist. In the theatrical release and regular DVD, a second Uruk then asks of the painted one, "What is it, what do you smell?" and he answers, "Manflesh." The very next shot is of Pippin saying, "Aragorn," followed immediately by the second Uruk saying, "They've picked up our trail." The Uruk who should have the painted hand on his face no longer does. He gives a low growl, then all the Uruk-hai run again. However, in the extended DVD, same scene, when the painted Uruk holds his fist up, it cuts to the Orcs hiding behind the rock, and the very next shot is of those two Uruks, and just like in the regular DVD, the Uruk who is supposed to have the painted hand on his face, does not. It is that Uruk who later in the scene says, "Manflesh," and unlike the regular DVD, without the painted hand on his face. Side note: It may be a different Uruk standing next to the 'second Uruk', in the questionable shots and that's why he doesn't have a painted face, but either way, it's still a mistake between shots. (00:14:50)Super Grover
Continuity mistake: Just before Legolas surfs the shield down the stairs, he is holding the shield in his right hand and his bow in his left hand, which is down. In this shot, he starts to toss the shield down onto the ground, still clutching the bow in his left hand. In the next consecutive wide shot, the shield is still in mid-air, and as he is starting to run towards the moving shield, Legolas does not have the bow in his left hand now. He did not throw the bow over his shoulder. The next shot is a close-up of his feet on the shield, just starting to come to the stairs. In the next wide shot, as he is starting to surf at the top of the stairs, Legolas has the bow in his left hand again and he is lets loose the arrows at the Uruk-hai. (01:11:00)
Continuity mistake: When Aragorn is lying on the couch in Arwen's home, during the dream/flashback sequence, he at first has the edge of a grey/green pillow visible just above his right shoulder. After a cut to Arwen and then back to him again, the pillow has slipped down so that it cannot be seen behind his shoulder, though he hasn't moved yet. When he stands, the pillow can be seen on the couch.
Continuity mistake: When Gollum is trying to catch the fish in the rocky bed of water, in the wide shot, Frodo and Sam are walking in the background. The background seen behind Sam and Frodo in that wide shot, is very different to the background in the very next shot, seen behind Frodo and Sam, when Sam says, "Hey stinker," and in the rest of the shots in this scene. The column in the wide shot is the same column seen behind Sam, when he says, "Because. Because that's what he is Mr. Frodo." There are three distinctly different columns shown in the close-ups! (01:36:50)Super Grover
Continuity mistake: Faramir and his men, along with Frodo and Sam, are looking out towards Osgiliath, when someone says, "Osgiliath burns, Mordor has come." Originally, Minas Tirith is seen as well, as it should be, at the base of the mountains behind Osgiliath, which is geographically correct. However, Peter Jackson was forced by studio heads to edit it out of the theatrical version, because it was felt that seeing Minas Tirith then would confuse some viewers, who would think that Minas Tirith was Helm's Deep. In the extended DVD, much to the satisfaction of PJ, Minas Tirith was put back in order to be geographically correct. As heard on Commentary, extended DVD. (01:20:40)Super Grover
Continuity mistake: When Merry and Pippin are at the Entmoot, in several of the front coverage shots, Merry is several feet in front of Pippin and slightly to the left. From the back at a distance, however, they are next to each other with Merry on the right. While there are some shots in which they are both moving around, accounting for the difference, here they are both stationary. Extended DVD, Disc 2 (01:11:50)