Continuity mistake: During the speeder chase scene, Leia jumps from her speeder and it blows up, the stormtrooper then hits a tree. The camera shows the tree as a hollow shaft, but when the stormtrooper smashes into it, suddenly it is solid. (01:58:15)
Continuity mistake: Widescreen version: After Leia tells Han that Luke is her brother, she kisses him, and then removes her hand from his neck twice. (01:59:20)
Continuity mistake: When Han and Leia kiss after the Death Star explodes, after Wicket shows up, Han's hand is on the back of Leia's head. In the next shot, his hand is on her arm, and Leia's thumb is touching his jaw, which it didn't do in the previous shot. (01:59:30)
Continuity mistake: Widescreen version: When Darth Vader dies, the chin part of his helmet is missing in the last shot. (02:01:30)
Revealing mistake: When Luke is being fed to the Rancor, in Jabba the Hutt's dungeon, there are black outlines around the beast's legs, from the composite's blue screen special effect. This was edited out in the special edition rerelease.
Continuity mistake: On the forest moon of Endor when Princess Leia first meets the Ewok, she takes her helmet off and is holding it in her hand (which frightens the Ewok) in the very next shot she is removing it again to show it to him.
Revealing mistake: The shots at the end of the movie with the emperor are obviously lit from the front. This exposed too much of the emperor's head inside the cowl so it was darkened to make him look more menacing. Look for the added shadow - it looks like someone took a black magic marker and coloured on the film. (This may be corrected on the re-release).
Audio problem: When they are fighting on the smaller skiffs above the Great Pit of Carkoon, Luke beckons to Leia to get her to swing on that rope with him to safety. He says "come on", but his mouth never moves.
Continuity mistake: When Vader is driven to his knees during the duel, his elbow is over the handrail, but when Luke cuts off his hand, Vader's wrist is lying over the handrail instead.
Continuity mistake: When Lando is hanging over the pit, he has gloves on, then he has no gloves, then they're back and so on.
Continuity mistake: When Wicket wakes up Leia in the woods, the hooded garment he is wearing changes length between shots.
Revealing mistake: (Original theatrical release) When the imperial officer yells "Freeze", he is transparent and you can see the reactor through him.
Revealing mistake: In many far away shots of the sail barge you can see it is on a dune rather than in mid air.
Continuity mistake: Before Chewbacca and two Ewoks swing on a vine to the roof of one of the AT-ST walkers, in a shot of them running, Chewie's bandolier is on the wrong side.
Continuity mistake: In the sequence of the Emperor torturing Luke, there are several close-ups of Vader. Look at his helmet - it goes back and forth between being clean and being dusty.
Revealing mistake: When Luke is in his X-Wing preparing to make the jump to Dagobah, you can see the red text in the TV-type viewer in the cockpit has been superimposed as it remains stationary relative to the frame even when the cockpit is moving around.
Other mistake: When Vader first arrives at the station, he and the Commander are walking past rows of troops. If you look carefully, you will see a Stormtrooper in the back row with his helmet tipped so far forward it's almost off.
Visible crew/equipment: After Luke cuts Vader's hand, there's a shot of the Emperor walking downstairs. The shadow of the crew is visible on the lower left corner of the image. It can't be the shadow of Luke.
Continuity mistake: The birthmark on Leia's back keeps changing sides during the 'Jabba' scenes. This seems to happen when Jabba's tail changes sides. I guess the model of him only went one way, so they flipped the negative.
Continuity mistake: On Endor, when the stormtroopers come to take Luke away, the door of the lift is heard opening, the stormtroopers are heard walking, and then they appear behind Luke three seconds after the door opened. But in the next shot, we can see that Luke and Vader are too far away from the lift for the stormtroopers to reach them that quickly.
Suggested correction: This was not a "mistake". The outlines showing around the beast's leg were due to the limited CGI technology at the time the film was made. With advances in special effects in the following decades, the filmmakers were able to enhance the CGI quality in later releases.
raywest ★
But it is a mistake to show that the Rancor is not real, and the outlines show that. It's certainly not intentional.
lionhead
Not sure what you mean that the rancor is not real. Of course it's not real. The issue is, at that time, it was not technically possible to show the beastie without the lines showing. I classify a mistake as something that was not intentional. In this case, it was, due to the limitations of CGI in the 1980s.
raywest ★