In a dystopian near future, the city of Detroit is on the brink of societal and financial collapse. Overwhelmed by crime and dwindling resources, the city grants the mega-corporation Omni Consumer Products (OCP) control over the Detroit police force. OCP Senior Vice President Dick Jones demonstrates ED-209, a law enforcement droid designed to supplant the police. ED-209 malfunctions and brutally kills an executive, allowing ambitious junior executive Bob Morton to introduce the Chairman ("The Old Man") to his own project; RoboCop.

Meanwhile, officer Alex Murphy is transferred to the Metro West precinct. Alongside his new partner Anne Lewis, Murphy pursues notorious criminal Clarence Boddicker and his gang—Emil Antonowsky, Leon Nash, Joe Cox, Steve Minh—who ambush and torture Murphy until Boddicker shoots him in the head. Morton has Murphy's corpse converted into RoboCop, turning him into a powerful and heavily-armored cyborg with no memory of his former life. RoboCop is programmed with three prime directives: serve the public trust, protect the innocent, and uphold the law. A fourth prime directive, Directive 4, is classified.