I found Philip K. Dick’s short story Paycheck far more subtle and fascinating than the film. There are a number of differences. I will list a few examples. Jennings has only 7 items compared to 20; a code key, a ticket stub, a parcel receipt, a length of fine wire, half a poker chip, a green strip of cloth and a bus token. Out of those, only the code key and the bus token appear in the film. He refers to them as “trinkets” and describes them as his “pocketful of miracles, from someone who knew the future!”
In the film Jennings was a rich man after completing many jobs and memory wipes. In the story, no other jobs are mentioned and this is seemingly his first assignment. It lasts 2 years compared to the movies 3.
The character of Rachel has been invented for the film. In the short story there is a female character called Kelly who is a receptionist for the company. Jennings does turn to Kelly for help but she is not a love interest. I quite like the idea of Rachel, a woman he fell in love with while working for Rethrick but then forgets about when his memory is wiped. It also gives her a different motivation for wanting to help him and provides him with an ally he can trust.
In the story, Jennings tries to find Rethrick’s Plant, gain evidence of what he has been working on and blackmail him into letting him co-run the company. He has no safe place to go because the Security Police are after him and this is his only option. In the film he goes back to destroy what he helped to create because it has negative consequences for mankind and the police try to help him. But in the story it is the Government and the Security Police who are the bad guys, with their almost unlimited power and hold over the people, and Rethrick’s construction company are revolutionaries, trying to change the way things are.
The short story is more subtle and less flashy than the film. It has more sci-fi elements and is a lot more thought-provoking. The film takes the premise and tries to stretch it into an action film, adding in car chases and fight scenes. This unfortunately results in it detracting from the more interesting and provocative aspects of the story. If explored fully, these (and a vision of the future more akin to something like Blade Runner) would have resulted in a much more rewarding movie experience.