Star Wars: 20 Things You Didn't Know About Return Of The Jedi

In an earlier draft of the movie, Yoda (Frank Oz) didn't actually appear in it at all, but George Lucas felt compelled to add him to ensure that audiences were acutely aware that Darth Vader was indeed Luke Skywalker's (Mark Hamill) father.

Lucas even went to the lengths of consulting a child psychologist during pre-production, who convinced Lucas that unless it was flat-out confirmed by a trustworthy character that Vader was Luke's father, younger audiences under 12 years of age would simply reject it as untrue.

This was compounded when Vader voice actor James Earl Jones also concurred that he didn't believe Vader was telling the truth.

By having a character as impossibly wise as Yoda confirming it to Luke, there was no reason to linger on the dubious validity of the claim.