Director José Padilha and actor Joel Kinnaman fought hard for an R rating, but due to the ever expanding budget, which went from a modest $60 million and ballooned to $120 million, studio executives were forced to deliver a PG-13 rating in hopes of recouping the money the studio had spent on the film. Throughout the course of filming, studio executives kept a close eye on Padilha, making sure he was going to deliver a PG-13 rating.
During production of the film, director José Padilha phoned friend and fellow Brazilian director Fernando Meirelles to confide in him his frustration in the lack of creative control he was allowed by the studio for the project. Padilha estimated that for every ten ideas he brought to the project, the studio refused nine, and went on to the describe the making of the film as "The worst experience of [his] life". When word of this conversation became public, in an effort to appease the studio Padilha released counter statements expressing satisfaction with the film.
RoboCop having one human hand in his final form is a nod to the original RoboCop (1987), in which the technicians argue with Bob Morton about whether to salvage Murphy's arm after he was "killed" in the line of duty. In the original film, Morton callously nixes the idea and the decision is made to remove Murphy's surviving arm.
Dr. Norton's first name is Dennett, which is the last name of philosopher Daniel Dennett, who is famous for his work on consciousness and free will, both of which are key themes in the movie. Daniel Dennett argues that consciousness is an illusion created by layers of physical and chemical processes, and that consciousness is essentially computational. He nonetheless argues that his view is compatible with the idea of free will.
Jackie Earle Haley as Rick Mattox at one point says 'I wouldn't buy that for a dollar'. This is a reworking of a line in RoboCop (1987) during a fictional sitcom wherein the star of the show regularly uses the catchphrase 'I'd buy that for a dollar!'.
Basil Poledouris wrote the score for RoboCop (1987) and RoboCop 3 (1993), and his theme can be heard very briefly at the beginning of the movie while the "RoboCop" title credit is shown, and in the "Novak Element" broadcast where the character is introduced to the public after his first arrest.
Tom Pope (the PR-guy played by Jay Baruchel) tells Raymond Sellars about a focus group done at Ryan Correctional Facility, where the Combat Mode design "really put the fear of God into the prisoners". The design seen on the screen is the design of the original RoboCop from RoboCop (1987).
Hugh Laurie was in talks to play the role of Raymond Sellars, but contract negotiations broke down between him and the film's producers. Clive Owen was seriously considered as a replacement before Michael Keaton was cast.
At least two characters in the film are named after important philosophers with strong views on artificial intelligence (AI). Sen. Hubert Dreyfus may be named after the American philosopher Hubert Dreyfus, who has extensively criticized the limits of AI research and denies that AI can ever truly attain human-level cognition, i.e., thought. Dr Dennett Norton may be named after Daniel C. Dennett, a contemporary and correspondent of Dreyfus' who believes that AI may be feasible, but that it is probably neither necessary nor worthwhile to try to perfectly replicate human thought in software. Both references are obscure outside of the AI or philosophy communities but highly relevant to the film's themes of existentialism and self. Raymond Sellars may also be named after Pittsburgh philosopher Wilfrid Sellars, whose views have less direct relevance to AI.
There is a quote from Michael Crichton's early book "The Terminal Man" in this film. While Murphy is getting his brain "repaired," the character talks about tasting peanut butter, but does not like it--exactly the same quote while the "Terminal Man" is getting his implant. That character also feared the idea of machines taking over mankind.
Joshua Zetumer wrote the script for remake based on unfinished draft by Edward Neumeier & Michael Miner, which they wrote in 1985 at the insistence of director Paul Verhoeven, who wanted to make the original film more serious, it was written 90 pages, after reading the material Verhoeven realized what was wrong and decided to return to the original concept of humor and brutal satire on the corporate future. Edward Neumeier talks about it in Starlog #127 for February 1988 in article "RoboWriters!" by Lee Goldberg.