FAQ

It is based on a short story Paycheck, written by Phillip K. Dick in the 1950s. There are several differences in the film and the original story (including the items Jennings gets from the envelope), but the basic premise is similar to the original. Notable features of the story that are different from the book are:

* Although the setting is 21-century America, it is a more dystopian future. A recent change in government has been referred to, the new government has a secret police force that supposedly never releases its detainees, the new government uses "credits" instead of "dollars", and individual citizens have significantly fewer rights than corporations do.

* Rethrick is a much older man and has no prior connection with Jennings.

* Although there is a potential love interest who works for the company named Kelly, she does not encounter Jennings until after the memory wipe and has a "surprise ending" secret that is not in the movie.

* Technology is significantly different. Erasing memory is a secret that most people do not know about (including the goverment agents who arrest Jennings). Rethrick's company still has significant manual labor. Cameras still require mechanical film. Rockets that transport people between cities are commonplace. And, the device that Jennings develops for Rethrick not only sees things but can also retrieve things.

* The plot features a lot more blackmail and threat of blackmail. Rethrick is generally unaware of Jennings' experiences after the memory wipe and it is Jennings who is looking for Rethrick, not the other way around.

* The climax of the short story is completely different from that of the movie. In the story, Jennings sneaks into the company alone, rather than with a partner as in the film (in the story he enlists Kelly's help, but simply asks her to keep whatever he finds safe so that it doesn't fall into the hands of the authorities) using a piece of cloth among his belongings that identifies him as a worker. He also had no interest in destroying the machine (identified as a "time scoop"), he simply wanted to photograph it (the device itself was illegal and the company was part of a resistance against an oppressive government). The film also adds in a climatic shootout that destroys most of the building, while in the original short story Jennings merely snuck out through a back door he had left himself a key to.

* The movie ends with Rethrick being killed while Jennings escapes and goes on to live with Rachel; the short story ends with Jennings successfully blackmailing Rethrick into making him a partner in the corporation, hinting at the possibility that he may eventually find a way to take over.