Very little original material in Star Wars.
Well, that's a given. Lucas built his whole career on homage and pastiche. The only reason he created SW was because he couldn't get the film rights to Flash Gordon
. And what he created instead was a hodgepodge of references to old adventure serials, war movies, Westerns, and the like -- though what made it fresh, at least in the original film, was the more modern, irreverent, affectionately deconstructive approach he took.