For real he gets all the credit for the script of Episode 5 but in reality he prob. just made some dialogue and other minor changes to the second draft from George. Actually Kasdan played a much larger role on Return of the Jedi than he did on Empire. Lawrence Kasdan quote from Starlog #51 (October 1981): PS: And I still wonder why Lucasfilm even put Leigh Brackett name in the credits. From what I read George absolutely hated her 1st draft and made a completely new one that kasdan than "enhanced". Did they do this out of respect, because of her death ? And why isnt George mentioned in the credits as screenwrter ? edit: That explains a lot. George Lucas quote from Star Wars: The Annotated Screenplays: That was very nice of him. But in retrospect it was the wrong decision. I hope he can add his name there someday, because he derserves it.