* DeletedScene: In original script, there was a scene where Jacob burns down some army headquarters building in fit of rage. This scene was filmed but deleted and was never released, although a picture of Jacob holding the torch and gasoline can from this deleted scene was shown in Bravo's ''Series/OneHundredScariestMovieMoments'' where the film is discussed.
* MissingTrailerScene: Teaser, theatrical and TV trailers show several scenes deleted from original cut;
** A disfigured man attacks Jacob with knife, this scene was originally in the beginning where after he is almost run over by subway train Jacob goes into men's room where he finds one man raping another while second one pulls a knife on him. Scared Jacob then escapes from the subway.
** Jacob is sitting in his mail van and reads a book when suddenly he sees bag of mail starting to move. Originally in this scene some homeless man was sleeping inside the van and when Jacob finds him he takes him out of the van and gives him some money.
** Jacob's and Jezzie's sex scene.
** An extra line from Frank when he is talking with Jacob on the phone; "Maybe the demons are real."
** A longer version of "Hospital From Hell" scene. While he is on gurney pushed through some hallway Jacob asks; "Where are you taking me? Where am i?"
** A deleted antidote scene which is available on special edition DVD/Bluray. In this scene Michael gives Jacob antidote which causes Jacob to start hallucinate the blood dripping on him and monster crashing through the ceiling.
** While the theatrical trailer shows shot of Jacob screaming "Who are you" from deleted Jezzie's transformation scene (available on special edition), the teaser trailer shows alternate version of the scene with Jezzie's face getting disfigured and her turning into different looking demon then in the deleted scene.
* SavedFromDevelopmentHell: Bruce Joel Rubin's script was considered "unfilmable" for 15 years, while ''Sight & Sound Magazine'' called it the best unproduced script in Hollywood. Adrian Lyne bravely tackled the confusing, crazy story and managed to distill it and ground it in reality.
* ThrowItIn: According to Adrian Lyne, most of the dialogue in the opening scene between the soldiers was improvised on set by the actors themselves, especially the conversation between George and Jacob about masturbation.
* TooSoon: In a 2015 retrospective on the film, Creator/TimRobbins said that one of the reasons he thought it didn't do well at the box office was how the film's violent, harrowing scenes in Vietnam didn't jibe with the national mood in the fall of 1990 during the run-up to the Gulf War.
* WhatCouldHaveBeen:
** According to Adrian Lyne, the original screenplay contained a much more traditional, [[Creator/HieronymusBosch Bosch-esque]] depiction of hell. However, Lyne thought audiences would find such imagery silly.
** Michael Apted, Creator/SidneyLumet and Creator/RidleyScott all tried to get the project green-lit during its several year period of non-production.
** Candidates for Jacob Singer included Creator/RichardGere, Creator/TomHanks[[note]] He turned it down in order to star in ''Film/TheBonfireOfTheVanities'' [[/note]], Creator/DustinHoffman, Don Johnson, Creator/AlPacino and Creator/MickeyRourke.
** Music/JenniferLopez, Music/{{Madonna}}, Andie [[==McDowell=]], Creator/DemiMoore, and Creator/JuliaRoberts were considered for were considered for Jezzie.
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