* ActorAllusion: Sebastian hands Kathryn a magazine that has Jennifer Love Hewitt on the cover. Both Ryan Phillippe and Sarah Michelle Gellar had starred alongside her in ''Film/IKnowWhatYouDidLastSummer''.
* DawsonCasting: Ryan Phillippe was twenty-five, Reese Witherspoon twenty-three, Sarah Michelle Gellar twenty-two and Sean Patrick Thomas was nearly ''thirty''. Selma Blair, meant to be a freshman, was the oldest of the actors playing the teens.
* MethodActing: When Annette slaps Sebastian in the face [[spoiler: during their breakup scene]], the slap wasn't supposed to happen. Both Ryan Phillippe and Creator/ReeseWitherspoon became caught up in the intensity of the scene that she impulsively slapped him. Sebastian's look of shock was genuine [[spoiler: and Ryan even threw up after the scene was finished filming]].
* OldShame: ''Cruel Intentions 2'' is this for Amy Adams, though she does poke fun at it.
** In ''Cruel Intentions 2'', Ryan Phillippe's and Sarah Michelle Gellar's roles were recast with Robin Dunne, king of the direct-to-video sequels, and an up-and-coming Amy Adams, respectively.
** In the upcoming TV series reboot, Reese Witherspoon's character has been recast with similar-looking actress Kate Levering.
* PlayingAgainstType: Both of Kathryn's actresses. Sarah Michelle Gellar was known either as an ActionGirl or else a wholesome character in some way. Amy Adams is now best known for doe-eyed cutie roles.
* RomanceOnTheSet: Ryan Phillippe and Reese Witherspoon were dating and got married for seven years.
* SoMyKidsCanWatch: An odd variation, given the film's subject matter. But Christine Baranski signed on because her kids were huge ''Buffy'' fans and were ecstatic at the thought of their mother working with Sarah Michelle Gellar.
** The original ending, in script form, can be viewed [[http://www.dailyscript.com/scripts/cruel-intentions.html here.]]
** The title was going to be 'Cruel Inventions', but it was changed because it sounded too much like the title of a sci-fi movie.
** The studio were lobbying hard for Katie Holmes to play the role of Annette, but Roger Kumble didn't think she had the strength of character for the role.
** A scene was filmed showing Sebastian hitting Kathryn. The filmmakers deleted it to suggest that Kathryn could have been lying when she tells Ronald that Sebastian hit her.
** ''Cruel Intentions 2'' was originally conceived as a spin-off TV series, but ended up getting released as a direct-to-video sequel.