The film utilized the punk look and image that was becoming part of popular culture in the early 1980s. The theme song, "I Am the Future", was performed by Alice Cooper. The film also features a performance by Canadian punk band Teenage Head.
Andrew Norris (Perry King) is the new music teacher at a troubled inner city school. As he arrives on his first day, he meets fellow teacher Terry Corrigan (Roddy McDowall), who is carrying a gun. When Norris asks about the firearm, Corrigan assures the new teacher he will soon know why such protection is necessary. When they enter the school, Norris is shocked to see everyone scanned by metal detectors and frisked. He spots a student with a knife, but the security guards let the kid go because they are so overworked.
The halls of the school are covered with graffiti. Norris learns he is expected to patrol the halls as a security guard during his off periods. In his first class, a group of five disruptive students are roughhousing and causing trouble. The leader of the gang is Peter Stegman (Timothy Van Patten), the only member of the group who is actually registered in that class. They all eventually walk out, and Norris discovers the rest of the students actually want to learn, especially Arthur (Michael J. Fox), who plays the trumpet, and Deneen, who plays the clarinet.
As Norris gets to know the school and the area, he decides that he wants to put together an orchestra with his more advanced students. The film follows Stegman's gang as they sell drugs, run a strip club, and cause all kinds of mayhem. They follow Norris home and taunt him one night.
At school, Norris is confronted with more and more evidence of Stegman's crimes. The two grow increasingly at odds. Eventually, they wind up in a bathroom alone together. Stegman throws himself into a mirror and beats himself up before claiming that Norris attacked him. Trying to clear things up, Norris visits Stegman's mother at home. Frustrated when Stegman still plays the victim and his mother will not hear Norris out, he hotwires Stegman's car and drives it into a wall.
The film climaxes as Norris' orchestra is about to give its first concert. As his wife gets ready at home, Stegman's gang breaks into the house and gang rapes her. One of them takes a Polaroid of her being raped and has it delivered to Norris on the podium, just as he is about to start the concert. Horrified by the photo, Norris runs off the podium in pursuit of Stegman's gang. The remainder of the film depicts Norris and the gang chasing each other through the school. Norris kills them off one by one, and he finally confronts Stegman on the roof. Their last scuffle ends with Stegman falling through a skylight and getting tangled in the ropes above the stage. He falls into full view of the audience as his neck is broken by one of the ropes.
The film ends with a title that claims Norris was never charged because the police could not find a witness to the crime.
The film premiered on August 20, 1982 in the United States.
When originally released in the United Kingdom, the theatrical version received four minutes and fourteen seconds of cuts from the British Board of Film Classification, and was refused a video certificate four years later. It was finally passed fully uncut in 2005.
Upon original release, the film was banned in several countries due to its lewd content. It currently maintains a 75% fresh rating on Rotten Tomatoes based on 15 reviews.
Scream Factory released the film in a Collector's Edition Blu-ray on April 14, 2015.
Comedy writer/producer Tom Scharpling has noted that Class of 1984 is one of his favorite films. Scharpling would often reference the film on his weekly call in radio program The Best Show on WFMU.
The film spawned two sci-fi-themed sequels that were loosely based on the original: Class of 1999 (1990) and the direct-to-video follow-up Class of 1999 II: The Substitute (1994), the first of which was also directed by Lester and like its predecessor, was also released via Vestron Video, while the latter was released by Vidmark Entertainment. Lionsgate released Class of 1999 on DVD September 16, 2008. They have been released on DVD in many foreign territories, such as Korea, Italy and Australia.