Sir Christopher Nolan told TIME Magazine that he had to deal with leading actors with highly different approaches. Al Pacino insisted on meticulous preparation, serious talks about character motivation and lots of takes, Robin Williams preferred hardly any rehearsal, but many takes, and Hilary Swank wished to do just a few takes to stay completely focused. Nolan therefore let Pacino and Williams freely experiment and work things out together, in order to get attuned to each other.
As of 2024, this is the only film directed by Sir Christopher Nolan in which Nolan does not have an official writing credit - even though he wrote the final draft of the screenplay himself.
After he saw Memento (2000), producer Steven Soderbergh knew he had found the perfect director for this film.
Will Dormer's name comes from the French, Spanish and Portuguese word "dormir" - to sleep.
Although primarily known for comedic roles, this is one of two thrillers in which Robin Williams starred in the same year. The other one was One Hour Photo (2002).