According to the the 'Robert Downey Jr Film Guide' web-site, 'Marek Kanievska' suggested Robert Downey Jr. and Andrew McCarthy should go out and party to 'get into character' which ended with Downey in the middle of Santa Monica Boulevard, howling at the moon, and McCarthy had to bail him out of jail.
Bret Easton Ellis hated the film initially. He admits that the film bears no resemblance to his novel but that it captured, "a certain youth culture during that decade that no other movie caught", and felt that it was miscast with the exceptions of Robert Downey Jr. and James Spader. Furthermore, he has said, "I think that movie is gorgeous, and the performances that I thought were shaky seem much better now. Like, Jami Gertz seems much better to me now than she did 20 years ago. It's something I can watch".
Because the novel didn't have a central plot or a core set of protagonists, but was more a set of interwoven events happening to a larger group of friends, this film differs considerably from the novel. In a surreal twist, the sequel novel, 'Imperial Bedrooms', has the original novel's characters aware of the film version of "Less Than Zero".
A test screening of 15 to 24 year olds revealed that the sample disliked Robert Downey Jr.'s character. So reshoots were conducted with additional footage to show his and Jami Gertz's characters in a better light which included the happy and celebratory early graduation sequence.
Both the book and film of Less Than Zero (1987) and its reported sequel, titled Imperial Bedrooms, are named from an Elvis Costello song and album respectively. "Less Than Zero" is the first single off of the "My Aim is True" (1977) album whilst "Imperial Bedroom" is the name of Costello's 1982 album.
Robert Downey Jr. plays a drug addict in the film. This proved prophetic, as he suffered drug and alcohol addiction in later life. He recalled: "Until that movie, I took my drugs after work and on the weekends. That changed on Less Than Zero (1987), the role was like the ghost of Christmas future. The character was an exaggeration of myself. Then things changed and, in some ways, I became an exaggeration of the character".
In an interview, source novelist Bret Easton Ellis once said of this film adaptation of his book 'Less Than Zero': "Of course, I envisioned everybody in the book as blonde and everybody in the movie is a brunette".
Cinematographer Edward Lachman has said that the completed picture was originally a lot edgier and the 20th Century Fox studio, who felt the property was too edgy anyway and had limited the film's cost budget, wanted to tone down the movie and make it more commercial audience friendly, and did this by taking the film away from director Marek Kanievska in post-production.
Jami Gertz is the actress who plays Blair in this movie based on the first novel by Bret Easton Ellis. In another book written by Ellis, "American Psycho", Patrick Bateman inquires about actress Jami Gertz at the Video Visions video store in New York's Upper West Side. The video store clerk does not know who Gertz is. Bateman then fantasizes briefly about having sex with Gertz while trying not to pay attention to someone talking to him.
According to the 1987 article "Sanitizing a Novel for the Screen" published in 'The New York Times', Pulitzer Prize-winning playwright Michael Cristofer, who wrote a screenplay for this film that got rejected, said the experience working on this film was an ugly one.
Cinematographer Edward Lachman remembers that originally the film was a lot "edgier" and that the studio took it away from Marek Kanievska. He also recalled a scene he shot with Red Hot Chili Peppers: "The Red Hot Chili Peppers were in that film and the studio became very conservative and they said, 'Oh the band, they're sweaty and they don't have their shirts on.' They destroyed an incredible Steadicam shot, all because they had to cut around them being bare-chested".
The producers and 20th Century Fox studio executives frequently argued about amount of decadence that would be depicted in this movie with the film being "meetinged to death" as the New York Times reported.
Producer Marvin Worth in June 1985 first optioned the film rights to Bret Easton Ellis' then unpublished "Less than Zero" novel by purchasing an option for the small amount of US $7,500 on the proviso that the 20th Century Fox film studio would make the movie.
The last name of Andrew McCarthy's character, Clay Easton, is the same name as the middle name of source novelist Bret Easton Ellis. Clay's surname was not given in Ellis' source "Less than Zero" novel. Its use here in this film is a direct reference to the author.
Some of the film's english translations of this film's foreign film titles, according to the "Robert Downey Jr. Film Guide" website, were as follows: "Argentina: Corrupción en Beverly Hills (Corruption in Beverly Hills); Brazil: Abaixo de Zero (Less than Zero); Denmark: Livet i overhalingsbanen (Life in the Fast Lane); Finland: Alta Nollan (Under Nothing); France: Neige sur Beverly Hills (Snow on Beverly Hills); Germany: Unter Null (Under Zero); Israel: Young in Trap (English translation); Italy: Al Di Là Di Tutti i Limiti (Beyond All the Limits); Poland: Mniej Niz Zero (Less Than Zero); Spain: Golpe al Sueño Americano (A Blow to the American Dream); [and] Sweden: Noll Att Förlora (Nothing to Lose)".
Marek Kanievska was hired as director for two reasons and these were based on his direction of his critically acclaimed 1984 film Another Country (1984). This was because Kanievska had in that film (1) fashioned unsympathetic characters making them sympathetic and (2) been able to handle themes of bi-sexuality and sexual ambivalence.
Pulitzer Prize-winning playwright Michael Cristofer to write the screenplay. He stuck close to the tone of the novel and had Clay take some drugs but did not make him bisexual. The studio felt that Cristofer's script was too harsh for a commercial film.
Studio executives and Jon Avnet argued over the amount of decadence depicted in the film that would not alienate audiences. Larry Gordon, President of Fox, and who had approved the purchase of the book, was replaced by Alan Horn who was then replaced by Leonard Goldberg, who found the material distasteful but Barry Diller, the Chairman of Fox, wanted to make the film.
Marek Kanievska was hired to direct because he had dealt with ambivalent sexuality and made unlikeable characters appealing in his previous film, Another Country (1984). Jon Avnet felt that Cristofer's script was "so depressing and degrading." Avnet instead wanted to transform "a very extreme situation" into "a sentimental story about warmth, caring and tenderness in an atmosphere hostile to those kinds of emotions".