Hard to TL;DR because it's a twisty tale that doesn't make a lot of sense. It was the name of an unrelated book by an obscure author that was adapted into a "f

Hard to TL;DR because it's a twisty tale that doesn't make a lot of sense. It was the name of an unrelated book by an obscure author that was adapted into a "film treatment" by Willam Burroughs; and it was sitting on the right shelf when Scott and Co. were scratching around for a title. Neither manuscript had an influence on the final film, and the term "Blade Runner" is never explained in the film.