* AbilityOverAppearance: Charlize Theron was initially turned down for being too pretty for the role. She was allowed to screen test three more times, playing different emotional scenes. Despite the long process, it convinced Taylor Hackford and the Warner Bros executives that she could play the role.
* ActorInspiredElement: Al Pacino came up with the idea of dancing to Frank Sinatra's "It Happened In Monterey".
* AwesomeDearBoy:
** Creator/AlPacino was on-board to play Milton from the word go, with the director and screenwriters actively adapting and reworking the script to ''add lines'' for him to say at Pacino's suggestion (contrary to popular belief, Pacino [[ThrowItIn didn't ad-lib his monologues]], but he ''did'' make suggestions for their content and only really asked for one big speech at the end... to which Hackford responded by giving Pacino all the monologues he felt the script could support).
** For his part, Creator/KeanuReeves signed on for the project mainly for the chance to work with Pacino. To the extent he took a huge paycut (we're talking ''millions'') so they could afford to hire him on.
** Charlize Theron thought long and hard about appearing nude, having turned down ''{{Film/Showgirls}}'' precisely because she hadn't wanted to. But she loved her character so much, so decided to do so.
* CastTheExpert: Connie Nielsen was cast as Christabella for her ability to speak several languages.
* DistancedFromCurrentEvents: Quite possibly one of the strangest reversals of this. The project was in development hell...until the OJ Simpson murder trial and its controversial outcome, with sensationalist trials now becoming a national talking point. The film even got a $60 million budget!
* DoingItForTheArt: The production couldn't afford to hire Creator/AlPacino so Creator/KeanuReeves gave up part of his salary because he thought Pacino's participation would elevate the final product.
* FakeAmerican: Keanu Reeves is Canadian, Charlize Theron is South African.
* KeepCirculatingTheTapes: Due to a lawsuit over the sculpture in Milton's office[[note]]the original design with visible human figures was deemed too similar to ''Ex Nihilo'' by Frederick Hart who sued for copyright infringement[[/note]] the original theatrical cut of the movie only received a brief rental release before Warner Bros were forced to issue new copies editing all shots of the sculpture. These early copies have found their way into the hands of collectors and are the only way to see the unedited sculpture.
* MethodActing: To prepare for the role, Charlize Theron spent one hour every day with a psychotherapist to "practice schizophrenia". This film however soured her on the process, since the character got put through so much that she found it too hard to keep up. By the time of ''{{Film/Monster}}'', she'd learned to lighten the mood on set by cracking jokes, and preferring to feel the character's emotions instinctively.
* OrphanedReference: Maryanne gets suspicious that Kevin is being unfaithful, which makes a lot more sense with an earlier deleted scene; she'd be looking for him at Eddie's party, stumble upon people having a threesome and leave in disgust when they ask her to join them.
* PlayingAgainstType: Craig T Nelson in a villainous role, at the time best known for the heroic patriarch in the ''Poltergeist'' films and the sitcom ''Coach''.
* RecycledScript: The protagonist and his wife basically live different recycled scripts. Kevin's is basically ''Film/TheFirm'', with {{Satan}}, while Maryanne's is ''Film/RosemarysBaby''.
* SimilarlyNamedWorks: Another film from 1977 has 'The Devil's Advocate' as its English title (original German title ''Des Teufels Advokat''). It too is based on a novel, but a different one by Morris West.
* UnderageCasting: Maryanne is supposed to be close in age to her husband, who was played by 31-year-old Keanu Reeves. Charlize Theron however was only 21!
* WhatCouldHaveBeen:
** Creator/JoelSchumacher was originally set to direct the film in 1994 with Brad Pitt to star as Kevin Lomax. Creator/ChristianSlater, Creator/JohnCusack and Creator/EdwardNorton were then considered for the role.
** Originally the film was a more special-effects oriented, blockbuster-type movie and was turned down by Creator/AlPacino five times. But when Taylor Hackford went through a few script re-writes he offered it to Pacino again. Pacino liked it, but didn't think he could portray Milton properly, and suggested Creator/SeanConnery or Creator/RobertRedford instead. Creator/RichardGere and Creator/KevinSpacey were also considered.
** When Brad Pitt was still attached, Joel Schumacher had envisioned a scene where Kevin goes into the New York subway and it resembles the nine circles of Hell in the ''Divine Comedy''.