Originally, the film was supposed to focus on Ginny Field, who checked herself into a mental institution after her traumatic battle with Jason Voorhees in the previous film. The film would have been similar to Halloween II, with Jason Voorhees tracking down Ginny in the mental hospital similar to how Michael Myers stalked Laurie Strode in the sequel. This concept was abandoned when Amy Steel declined to reprise her role.
When first released, the film was intended to end the series as a trilogy. However unlike its sequel Friday the 13th Part IV: The Final Chapter (1984) and the later film, Jason Goes to Hell: The Final Friday (1993), Friday the 13th Part III did not include a moniker in its title to indicate it as such.
Following the events of the previous film, a seriously injured Jason Voorhees goes to a lakefront store to find new clothes. While there, he kills the store owner Harold with a meat cleaver slammed into his chest, and his wife Edna is impaled with a knitting needle through the mouth.
Meanwhile, Chris Higgins and her friends travel to Higgins Haven, her old home on Crystal Lake, to spend the weekend. The gang includes pregnant Debbie, her boyfriend Andy, prankster Shelley, his blind date Vera (who does not reciprocate his feelings) and stoners Chuck and Chili. After running into a old man named Abel, who warns them to turn back, the gang meetup with Chris' boyfriend Rick at their destination. Shelley and Vera get into a confrontation with bikers Ali, Loco, and Fox at a convenience store, who follow them to the Haven. When the bikers try to burn the barn down, Jason, who has been hiding in the barn, murders Loco and Fox with a pitchfork before beating Ali with a club, seemingly killing him. Later that night, Chris and Rick head out. While they are out, Chris tells Rick about how she was attacked by a disfigured man two years earlier, causing her to leave Crystal Lake in order to escape the trauma.
Back at Higgins Haven, Shelly wanders into the barn where Jason slashes his throat and takes his hockey mask. The now masked killer proceeds to shoot Vera in the eye with a speargun. He then enters the house and slices a head-standing Andy in half with a machete. Debbie has a knife shoved through her chest while resting on a hammock. When the power goes out in the house, Chuck goes down to the basement where Jason hurls him into the fuse box, electrocuting him. Chili is impaled with a hot fire poker. When Rick's car dies, Chris and Rick are forced to walk back to the house to find it in disarray. Rick steps outside to search the grounds, but Jason grabs him and crushes his skull with his bare hands.
Jason then confronts Chris, who narrowly escapes the house and tries to flee in her van. The van breaks down and Chris makes her way to the barn to hide but is attacked again by Jason, whom she hangs. Jason unmasks himself temporarily to free himself, and Chris recognizes him as the man who attacked her two years ago. A revived Ali tries to attack Jason, but he is quickly dispatched. The distraction allows Chris to take an axe and strike Jason in the head with it, who staggers momentarily towards her before collapsing. Exhausted, Chris pushes a canoe out into the lake and falls asleep.
Chris then has a nightmare of Jason running towards her from exiting the house, and of the decomposing body of Pamela Voorhees - her head reattached - emerging from the lake and pulling her in. The following morning, the police arrive and escort the disturbed Chris from Higgins Haven. Jason's body is shown to still be lying in the barn as the lake is shown at peace once again.
Steve Daskawisz (also known as Steve Dash) appears as Jason during flashback from Part 2. Betsy Palmer appears as Mrs. Voorhees during flashback from Part 2.
Initially, one of the earlier drafts for Part III was Ginny (Amy Steel) from the previous film being sent to a psychiatric hospital and confined there. Suffering from the events of Part 2, she eventually finds out that Jason Voorhees survived from his wound and tracks her down to the hospital, murdering the staff and other patients at the hospital. At the time, Steel turned down the role due to her involvement in other projects, and the draft was presumably changed due to Halloween II's similar approach. Screenwriter Popescu said casting was based on looks rather than talent.
The script for Part III called for Jason to wear a mask to cover his face, having worn a bag over his head in Part 2; what no one knew at the time was that the mask chosen would become a trademark for the character, and one instantly recognizable in popular culture in the years to come. During production, Steve Miner called for a lighting check, but none of the effects crew wanted to apply any make-up for the light check, so they decided to just throw a mask on Brooker. Martin Jay Sadoff, the film's 3-D effects supervisor, kept a bag with him full of hockey gear, as he was a hockey fan, and he pulled out a Detroit Red Wings goaltender mask for the test. Miner loved the mask, but during test shots it was too small. Using a technique called VacuForm, Doug White enlarged the mask and created a new mold to work with. After White finished the molds, Terry Ballard placed the new red triangles on the mask to give it a unique appearance. Holes would be punched into the mask, and the markings were altered, making it different from Sadoff's mask. There were two prosthetic face masks created for Richard Brooker to wear underneath the hockey mask. One mask was composed of approximately 11 different appliances, and took about six hours to apply to Brooker's face; this mask was used for scenes where the hockey mask was removed. In the scenes where the hockey mask is over the face, a simple head mask was created. This one piece mask would simply slip on over Brooker's head, exposing his face but not the rest of his head.
This was the first Paramount Pictures film produced in 3-D since Ulysses in 1954. The film was shot with the Arrivision "over and under" 3-D camera, the same that was used with Jaws 3-D. It was also the first film in the series to be presented in Dolby Stereo upon its theatrical release.
The film's music was composed by Harry Manfredini, who previously composed the scores of the series' first two installments. Upon the release of the third film in 1982, Gramavision Records released a LP album of selected pieces of Manfredini's scores from the first three Friday the 13th films. On January 13, 2012, La-La Land Records released a limited edition 6-CD boxset containing Manfredini's scores from the first six films. It sold out in less than 24 hours.
All tracks written by Harry Manfredini, except where noted.
The film opened in 1,079 theaters in 3-D taking in $9,406,522 its opening weekend and breaking the horror opening record held by the original Friday the 13th (1980). Domestically, the film made a grand total of $36,690,067. It placed number 21 on the list of the top-grossing films of 1982, facing strong competition from other high-profile horror releases such as Poltergeist, Creepshow, The Thing, Halloween III: Season of the Witch, Visiting Hours, Amityville II: The Possession, Silent Rage, The Beast Within, Cat People and Venom. As of 2014, it still stands as the fourth highest-grossing film in the Friday the 13th series and the third best selling in ticket sales; with approximately 11,762,400 tickets sold, it is surpassed only by the 1980 original with 14,778,700 tickets and Freddy vs. Jason with 13,701,900 tickets). The film also stands as the tenth highest-grossing R-rated film of 1982, the second-highest grossing horror film of 1982, the sixth largest box office opening of 1982, and adjusted for inflation it is the ninth highest-grossing slasher film of all time.
Friday the 13th Part III received generally negative reviews from critics upon its theatrical release. The review aggregator Rotten Tomatoes reports that 12% of 25 film critics have given the film a positive review; the average rating is 3.6 out of 10.
Janet Maslin of The New York Times stated that it "would be a little better than Part I or Part II even without 3-D". In continuing to compare the film to its predecessors, Maslin commented that "it's a little more adept at teasing the audience." The entertainment-trade magazine Variety provided a general consensus stating, "Friday the 13th was dreadful and took in more than $17 million. Friday the 13th Part 2 was just as bad and took in more than $10 million. Friday the 13th Part III is terrible, too." The magazine added, "There are some dandy 3-D sequences, however, of a yo-yo going up and down and popcorn popping." In a retrospective, Scott Meslow of The Week called it "an under-sung camp classic — cornier and goofier than either of its predecessors".
Jason's mask in this film became the molded appearance of Jason in Friday the 13th: The Final Chapter and in later installments. For his appearance in the film, Jason Voorhees was nominated for AFI's 100 Years...100 Heroes and Villains as one of the Top 50 Villains. Meslow cites the film's 3-D effects as paving the way for later horror films which also used the technique.
The film is recognized by American Film Institute in these lists:2003: AFI's 100 Years...100 Heroes & Villains:
Jason Vorhees – Nominated Villain
Friday the 13th Part III was first made available on home video on VHS, Betamax, Capacitance Electronic Disc, and LaserDisc and later on DVD, with the film presented only in 2D form. There was also a VHD release for Japan (Part IV and Part V would follow). The 3-D version of the film was eventually released as a part of the film's DVD "Deluxe Edition" on February 3, 2009. The "Deluxe Edition" and eventual Blu-ray release include both the 2D and 3-D versions of the film, as well as two pairs of blue and red 3-D glasses designed to look like Jason's mask.