In the sequence when we see 'audition tapes' on a TV screen, also various books and VHS covers are in the frame, that provide clues to Gaspar Noé's inspirations: Visible are titles that reference Luis Buñuel, Dario Argento and Romanian philosopher Emil Cioran, famous for his ultra-negative views on life and humanity.
Gapar Noé got the cast into the dissociative druggy psychosis mindset by preparing a collection of the best videos he could find on the web of people high on crack, high on ecstasy, high on acid. Also the dancers were encouraged to take whatever experiential aspects stuck out to them from the videos and run with them in the film.
The cast consists of professional dancers with no prior acting experience, with the exception of Sofia Boutella who is the only professional actress. Although Boutella had the dancing experience that the part required, she hesitated to join the film since there was no script. Director Gaspar Noé encouraged his cast to improvise extensively, with the only limitation that they couldn't reference contemporary things like smartphones, since the story is set in the 1990s.
Loosely inspired by a French urban legend from the 1990s. While Gaspar Noe and several other members of the crew claim to recall reading about similar incidents in the news, none can recall any specific details.
One of Gaspar Noé's best reviewed movies, a fact that, by his own admission, made him somewhat suspicious, as he believes art in general and his movies in particular should be divisive and make the audience uncomfortable.
The trivia items below may give away important plot points.
The opening and closing sequences in the snow were completely incidental and improvised. The small suburb inwhich the crew were filming in had 2 days of snowfall during the shoot, Gaspar then proposed they fly a drone over a local park.
Gasper Noé says he wanted to make a psychological drama that is the counterpoint to Stanley Kubrick's 2001 so much so that instead of seeing the apes evolve into humans, Climax is like the humans go back to being apes, humans are going back to their original forces.
According to Gapar Noé, the reason that "Angie" by The Rolling Stones was used at the end of the film is that he wanted something sentimental and famous to be playing at the end. "Hotel California" by Eagles and other songs by David Bowie and Lou Reed were also considered.
Although the title card "Birth is a unique experience" remains onscreen for several seconds, there are two additional title cards that appear almost subliminally, once in the opening credits and again near the end of the film. They read "Life is a collective impossibility" and "Death is an extraordinary experience."