George Lucas, Leigh Brackett, Lawrence Kasdan
So many different hands touched the screenplay for The Empire Strikes Back that it can be downright confusing at times. Luckily for us, Star Wars fans have taken care of a lot of legwork and we can now actually read the early drafts of this iconic film.
The script starts, as with most things in the Star Wars universe, with George Lucas. He started writing the sequel to A New Hope soon after its release in 1977, coming up with a basic outline of the story by the end of the year. Although this treatment resembles the final movie in many ways, there are some key differences, most notably that Darth Vader is explicitly not Luke's father, as his read dad appears as a ghost in one scene.
From there, Lucas turned his outline over to famed sci-fi author and screenwriter Leigh Brackett. This was a fanboy's dream come true for Lucas: Brackett was such a prolific sci-fi writer in the 40's that she was known as the "Queen of the Space Opera." As you can see from unearthed copies of her draft, Leigh took the film in a very different direction from the final product: Lando is a radically different character and Yoda is known by the drastically inferior name "Minch."
By all accounts, Lucas was greatly disappointed by this draft, but before he could discuss revisions with Brackett, she passed away from cancer. This sad event forced Lucas to go back to drawing board and rework his story from the ground-up.
A New Beginning
Lucas did exactly that. Although major story beats remained the same, Lucas simplified some confusing sub-plots and—most notably—added the twist that Vader is Luke's father. By all indications, this was never the original plan. Still, this decision is a pivotal moment in Star Wars history: It transforms our understanding of A New Hope, sets up the conflict for Return of the Jedi, and establishes the story arc for a prequel trilogy that wouldn't see the light of day for another twenty years.
After Lucas brought the story in line with his vision, he turned it over to screenwriter Lawrence Kasdan. Kasdan had worked with Lucas before, having just written the script for the Lucasfilm-produced Raiders of the Lost Ark. Boy do we mean that he had just written it: He was offered the Star Wars gig before Lucas had even read through his Raiders script. Kasdan would go on to co-write Return of the Jedi before taking a break from the series until 2015's The Force Awakens.
There are some notable subplots cut from the shooting script (a Wampa assault on the Rebel's Hoth HQ among them).
Also, some of the film's most famous dialogue, like Han's legendary "I know," was improvised. Still, after passing through the hands of three very talented, very distinct writers, The Empire Strikes Back was finally ready to make its way to the silver screen.