HuffPost has a great piece in response to the news that screenwriter Michael Arndt is no longer working on Episode 7. Mike Ryan points out that the script to The Empire Strikes Back changed massively as a result of the death of its original author, Leigh Brackett. From the piece:
The original Leigh Brackett draft of Empire is a bit of a marvel in and of itself. It's online if you want to read it (which I have), and it is really drastically different than what appeared in the final film. And it's an oddity worth exploring to illustrate just how much a story can change from the first draft to the final draft.
Brackett's version of Empire -- titled Star Wars Sequel Screenplay -- still starts on an icy planet that we all know now as Hoth, even though this planet's name is never identified (though Hoth will play a role later on in the script). The Wampas, which are basically relegated to the beginning of the final film, play a huge role in the first script, to the point that a massive battle breaks out between the Wampas and the Rebel Alliance (oh, also, Wampas have the power to freeze people with their touch).
During this battle, Luke Skywalker basically gets his ass handed to him by a Wampa, resulting in Han Solo barking sarcastic lines like, "The Force is not with you today, kid." Then Han explains to Luke how a lightsaber works (which is just weird in every way), "Those lightsabers were ceremonial weapons, even for the Jedi Knights."
Follow the link for more ESB weirdness, including the ghost of Luke's father (hint: he's not Darth Vader), the clone Lando Kadar, and Han's stepfather Ovan Marekal.