!!The novel
* CompletelyDifferentTitle: Known in France as ''Substance Mort'' ("Substance Death").[[note]]The film's title has been left untranslated[[/note]]
* WriteWhatYouKnow: The book was based on Creator/PhilipKDick's own experiences with drugs.


!!The film
* AwesomeDearBoy: Creator/RobertDowneyJr was attracted to the film when he heard Creator/KeanuReeves was going to star and Creator/RichardLinklater to direct. He thought that the script was the strangest one he had ever read. Creator/WoodyHarrelson and Creator/WinonaRyder agreed to appear in the film based on the script.
* DoingItForTheArt: Creator/KeanuReeves and Creator/WinonaRyder agreed to work for the Screen Actors Guild scale rate plus any back-end profits.
* RealitySubtext: Creator/RobertDowneyJr and Creator/WoodyHarrelson in a film about drug addicts.
* ReleaseDateChange: Originally, the film was supposed to be released in September 2005.
* SavedFromDevelopmentHell: Creator/TerryGilliam originally wanted to adapt the book in the early nineties.
* TypeCasting: The whole cast fits this trope. Who better to play a closed circle of stoners who sit around and shoot the shit than Creator/WoodyHarrelson, Creator/RobertDowneyJr, Creator/KeanuReeves, Creator/WinonaRyder and Rory Cochrane of ''Film/DazedAndConfused'' fame. You also have crazy conspiracy theorist Alex Jones making a cameo as a crazy conspiracy theorist. Honestly, it wouldn't be surprising if the psychiatrists in the movie were actually accredited psychiatrists. Could also be seen as MetaCasting.
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