Saw is a 2004 American horror film directed by James Wan, in his feature directorial debut, and written by Leigh Whannell from a story by Wan and Whannell. It is the first installment in the Saw film series, and stars Whannell, Cary Elwes, Danny Glover, Monica Potter, Michael Emerson, Ken Leung, and Tobin Bell. The film tells a nonlinear narrative, revolving around the mystery of the Jigsaw Killer, who tests his victims' will to live by putting them through deadly "games" where they must inflict great physical pain upon themselves to survive. The frame story follows Jigsaw's latest victims (Whannell and Elwes), who awaken in a large dilapidated bathroom, with one being ordered to kill the other to save his own family.
The screenplay was written by Whannell, who co-created the story with Wan in their respective screenwriting debuts. It was originally written in 2001, but after failed attempts to get the script produced in Wan and Whannell's home country of Australia, they were urged to travel to Los Angeles. In order to help attract producers they shot a low-budget short film of the same name from a scene out of the script. This proved successful in 2003 as producers from Evolution Entertainment were immediately attached and also formed a horror genre production label, Twisted Pictures. The film was given a small budget of $1.2 million and was shot in 18 days.
Saw was first screened on January 19, 2004, before being released in North America on October 29, 2004, by Lions Gate Films. The film received generally mixed reviews from critics but performed very well at the box office compared to its low budget, grossing more than $100 million worldwide and becoming, at the time, one of the most profitable horror films since Scream (1996). The film was theatrically re-released, to select theaters, on October 31, 2014 to celebrate its tenth anniversary. The first sequel, titled Saw II, was released in 2005.
Photographer Adam Stanheight awakens in a dilapidated bathtub, with his ankle chained to a pipe. Across the room is oncologist Dr. Lawrence Gordon with the corpse of an apparent suicide victim between them holding a revolver and a microcassette recorder. Both men find a tape in their pockets, and Adam retrieves the recorder. Adam's tape urges him to escape, while Gordon's tells him to kill Adam by six o'clock or his wife Alison and daughter Diana will be killed. Adam finds a bag containing two hacksaws inside the toilet which they try to use to cut through their chains, but Adam's saw breaks. Gordon realizes the saws are meant for their feet, and identifies their captor as the Jigsaw Killer—a serial killer testing his victims' will to survive through murderous contraptions referred to as "games", whom Gordon knows of because he was once a suspect.
Five months prior, Gordon, while discussing the terminal brain cancer of patient John Kramer, was interrogated by Detectives David Tapp and Steven Sing, who found his penlight at the scene of one of Jigsaw's games. Gordon's alibi cleared him, but he agreed to view the testimony of heroin addict Amanda Young, the only known survivor of one of Jigsaw's traps. After Gordon's release, Tapp and Sing found Jigsaw's warehouse using the videotape from Amanda's game. There, they apprehended Jigsaw and saved a man from a trap, but Jigsaw escaped after Sing triggered a shotgun trap in the hallway that killed him.
In the present, Alison and Diana are held captive at home as their captor watches Adam and Dr. Gordon through a hidden camera. The house is simultaneously watched by Tapp, having been discharged from the police after Sing's death and becoming obsessed with the Jigsaw case, convinced that Gordon is the killer. Meanwhile, Gordon finds a box containing two cigarettes, a lighter, and a one-way cellphone; recounting his abduction in a parking garage by a pig-masked figure who also captured Adam as well after the latter recalls his own abduction when he found a puppet in his photo development room.
Alison, held at gunpoint, calls her husband and warns him not to trust Adam, who admits to Gordon that he was paid by Tapp to spy on him and reveals his knowledge of Gordon's affair with one of his medical students whom he had visited the night he was abducted as the reason he is being tested. Adam finds a photo of Alison and Diana's captor whom Gordon identifies as Zep Hindle, an orderly at his hospital.
Once the clock strikes six, Zep, seeing that Gordon had still not managed to kill Adam, moves to murder Alison and Diana, but the former frees herself and fights him. The struggle attracts Tapp's attention, and he saves Alison and Diana before chasing Zep to the sewers, where he is shot in the chest after a brief fight. Gordon, only aware of the gunshots and screaming, is shocked and loses reach of the cellphone. In desperation, he saws off his foot and shoots Adam with the corpse's revolver. Zep enters the bathroom to kill Gordon but Adam, having survived the gunshot, bludgeons Zep to death with the toilet tank lid. Gordon crawls out of the bathroom to find help. Adam searches Zep's body for a key and finds another tape, revealing that Zep was just another victim of Jigsaw following rules to obtain an antidote for a slow-acting poison he was given.
The tape ends as the corpse rises and is revealed to be Kramer, the real Jigsaw Killer, who reveals to Adam that the key to his ankle chain was in the bathtub which went down the drain when he had first awoken. Horrified, Adam attempts to shoot Kramer with Zep's gun, but Kramer electrically shocks him through his chain and exits the bathroom before shutting off the lights and sealing the door, leaving a screaming and helpless Adam to die.