Looper started out as a three-page script that Johnson wrote for a short film, years ago. It was very voiceover-driven, and was essentially the opening monologue of the film, followed by a foot chase through the city after Joe's older self appears, while the voiceover continues and Joe talks about the moral conundrum he's facing. "At some point, I will put the [script] on the Internet," said Johnson. "I won't put it up now, because it does spoil the ending." A lot of the basic themes are there, but not the second half of the movie.
"When I wrote that short, it was right when I had discovered Philip K. Dick, and I was in the middle of blowing through all his works, so my was kind of steeped in that," said Johnson.