Trivia: The Special Edition covers of Return of the Jedi and Empire Strikes Back are wrong. The picture of the Emperor on ESB cover is from 'ROTJ', and the lightsaber duel between Luke and Vader on the cover of ROTJ is taken from 'ESB' (notice Luke is in his fighter pilot suit, and Vader is fighting him one-handed)
Trivia: When filming ROTJ, Lucas didn't want anyone to find out that they were shooting the third Star Wars movie, because pandemonium could break out. So when someone asked the crew what they were filming, they said "Blue Harvest". All of the crew had shirts and hats that said Blue Harvest on them. The fictitious film's tagline was "Horror beyond imagination."