Although the major con at the end of the movie is in the novel, it was left out of the first drafts of the screenplay for fear that audiences would feel cheated if their hero was left penniless. At the suggestion of director Ridley Scott, however, the con was put back into the screenplay and the last "One Year Later" sequence was added as a wrap-up.
Alison Lohman went to the audition dressed and acted like a 14-year-old girl. Ridley Scott only realized her real age when she told him. She was 22 at the time.
When Roy, Frank, and Chuck are having lunch... Roy tells Frank he's got to fly to Phoenix. Chuck is holding his wine glass by the stem, and in next camera view over his right shoulder, he's holding it by the globe.