Trivia: When Luke and Obi-Wan are talking after Yoda's death, Luke refers to him as Obi-Wan. This is the only time in any of the movies that he uses that name instead of Ben.
Suggested correction: If you are saying that this is the only time Luke refers to him as Obi-Wan, then yes, this is true. But if you are saying this is the only time Luke has ever said Obi-Wan, then you are incorrect; Luke uses the name Obi-Wan Kenobi in the first movie when explaining why he was so far from home.
Trivia: George Lucas included the scene in which Yoda confirms Darth Vader is Luke's father because, after a discussion with a children's psychologist, he didn't want younger viewers to dismiss Vader's claim as a lie.
Trivia: The Ewoks were originally going to be Wookiees, but because Chewbacca had already been shown to be able to fly a spaceship, not to mention repair it and be adept with energy weapons, Wookiees were too technologically advanced, so a new race had to be created.
Trivia: The voice of EV-9D9 in Jabba's palace is provided by the film's director, Richard Marquand.
Trivia: When Weequay falls into the Sarlaac pit during the sail barge assault, a "Wilhelm scream" can be heard.
Trivia: Harrison Ford actually wanted Han Solo killed in this movie. He said, 'He has no mama, no papa, no story. Let's kill him off and put some weight into this thing.' The higher powers that be thought otherwise.
Trivia: Watch Jabba's mouth when he speaks, and you'll notice it matches the subtitled English 'translation'. The puppeteer didn't know what 'language' would be used for Jabba, so during the take, he would say and mouth Jabba's lines as they were written in the script: in plain English.
Trivia: At the shield generator bunker (during the ambush), an Imperial Naval Trooper shouts "Freeze!" and when Han throws the charges at him the trooper falls backwards over the railing, and the famous "Wilhelm" scream is heard.
Trivia: Anakin Skywalker's first name is first mentioned in this film. His name comes from a friend of George Lucas, British film director Ken Annakin.
Suggested correction: Actually his first name first revealed in Empire Strikes Back when he is on call with the Emperor. He says, "I have no doubt that this boy is the offspring of Anakin Skywalker."
Anakin's name was not used in the original release of "The Empire Strikes Back", therefore the trivia is correct. George Lucas retconned the special edition release and added "Anakin." Originally Luke was referred to as the "son of Skywalker."
Trivia: During the Endor shooting, the Ewok actors stormed off the set. One of the crew members raced off to get them back, and it turned out to be a hoax. The actors came back laughing with t-shirts that read "Revenge of the Ewoks."
Trivia: Sebastian Shaw had no idea he would be playing Anakin Skywalker until the day he arrived on the set to shoot his scene.
Trivia: Though Mark Hamill's face seemed so different in this film than it was in the first two Star Wars films, people attributed it to a car accident. According to the actor, he had the car accident before Star Wars came out, but what really happened has been terribly distorted. He says he's many supposed stories about facial surgery, surviving a car wreck, and his favorite of all, driving off a cliff.
Trivia: While filming the scene in which C-3PO has his photoreceptor pulled out by Salacious Crumb, Anthony Daniels suffered a panic attack, due to the proximity of the puppet's beak to his real eye.
Trivia: Although David Prowse is listed as Darth Vader in the end credits, he only portrayed the character completely for the first half of the movie. For the second half, Vader was portrayed by Prowse's stunt double, Bob Anderson.
Trivia: George Lucas and director Richard Marquand clashed during production, due to Lucas favouring extensive camera coverage while Marquand preferred just one or two cameras. It has also been alleged by several people connected to the production, including Irvin Kershner (The Empire Strikes Back's director), that Marquand did not direct all the movie, and large portions of it were helmed by an assistant director and even Lucas himself, due to other actors not responding very well to Marquand.
Trivia: The special effects team used a rod puppet for the Rancor after they decided a man-sized costume looked unconvincing.
Trivia: When C-3PO is communicating to the Ewoks, one of the words he says is "Naboo." This was later revealed to be the home world of Queen Amidala (Luke and Leia's mother) in the film "Star Wars I - The Phantom Menace" (1999).