Catwalk

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: Vader tosses the Emperor and then collapses on some barrels next to the railing. Look at Vader's arm - the one with the severed hand. His arm is bent at the forearm in a way that arms just don't bend. This is because David Prowse's hand was inside an "elongated" arm to simulate it being chopped off. He couldn't keep his wrist straight, giving the appearance of a bent forearm. (01:57:00)

Continuity mistake: When Luke is riding the speeder bike against the trooper, the black glove on his right hand jumps to his left and then back again. (01:01:15)

ozwal13

Revealing mistake: In the wide-shot where Luke leaps from the prisoner skiff over to another skiff, you can see the stick used during the filming, which is much shorter than the regular one. The blade is not even glowing. (It is not just simply the hilt of the sabre, it's too long for that.). (00:32:15)

Continuity mistake: In the scene where Luke and the others are trapped in the net, the dead animal changes appearance (both injuries and actual appearance) and position several times. For example, the animal seen when they are in the net has a different mouth and a bigger area of white fur from the one seen a few shots earlier. (01:08:35)

Revealing mistake: When Jabba's sail barge begins to explode, you can see that one of the floating skiffs is standing on stilts. (00:36:30)

Continuity mistake: After Vader's shuttle lands on Endor, as the AT-AT is walking towards one of the ramps, you can see that the ramps are connected right next to the lift, under the landing pad. But when Vader exits the lift, there's a circular platform going around the lift, which wasn't there in the previous shots. (01:19:40)

Revealing mistake: Widescreen version only: After Luke cuts off Vader's hand, the Emperor says, "Now, fulfill your destiny, and take your father's place at my side." In the next shot, Luke's lightsaber blade goes through the railing, without damaging it. (01:49:15)

Other mistake: During the fight between Luke and Darth Vader, when Vader throws his lightsaber at Luke, it is not only Luke's lightsaber from Episodes IV & V instead of his own, it is ignited upside-down, with the blade protruding from the pommel rather than the emitter. (01:50:20)