Loosely based on the Stanford Prison Experiment, a group of ordinary people are recruited for a social experiment to test human propensities for control and defying control. The participants are selected into two groups of Prisoners and Guards, with the latter being told to maintain order by any means necessary absent direct forms of violence. It doesn't take long for the experiment to escalate beyond what the scientists intended.
This film provides examples of:
- Attempted Rape: One of the guards tries to rape the female scientist after previously having forced her to strip in front of him. He is interrupted when Prisoner #77 escapes from the Punishment Box.
- Barehanded Blade Block: A variation. The main character stops a knife blade by... gripping it with his hand! It sounds as painful as it actually looks, and the attacker is as perplexed as the defender by the unexpected move. It's made even worth because he apparently can't just open his hand again, so he has to pull the knife out from his closed fist, effectively slicing his palm and fingers even more.
- Drunk with Power: Deconstructed, in that it's shown that both the Guards and the Prisoners ultimately contribute to the escalation. At first the Guards limit themselves to minor abuses such as forcing a man with lactose intolerance to drink his required dosage of milk, but when the prisoners start to riot (largely because of prodding from Prisoner #77, who's a plant from a newspaper looking for a good story) they start resorting to increasingly violent methods to keep control over them. By the end the Guards are beating the Prisoners into comas, keep the junior scientists who are supposed to be monitoring the experiment captive so they can't interfere, and one of them even tries to rape a woman from the staff.
- Gone Horribly Wrong: The plot is based on the Stanford Prison Experiment, but goes further. Within just a few days the guards are terrorizing and humiliating the prisoners to keep order, right up to abusing their position of power to commit murder and rape. The head scientist was even aware how quickly the experiment was escalating, he just chose to ignore it For Science!.
- Historical Villain Upgrade: Later reviews of the study revealed that both the guards and the prisoners were coached into their roles and many instances of cruelty were the subjects acting, making it highly unlikely that this would have happened. Justified, in that this wasn't known when the film was made.
- A Nazi by Any Other Name: The film emphasizes the Nazi-like aspects of the guards' behavior. In case the point isn't obvious enough, their leader actually resembles a blond Hitler. At one point, one of the prisoners even calls him a Nazi. The experiment itself, along with the Milgram Obedience Experiment, were originally devised as an attempt to understand what would drive otherwise good people to commit the atrocities that the Nazis perpetrated during World War II.
- Punishment Box: Prisoners who are a routine problem are locked inside a safe. Prisoner #77 is locked inside in the climax when the guards have gone completely Drunk with Power, but he manages to break free on his own eventually.
- Rape Is a Special Kind of Evil: The main guard who spearheads the abuse of the prisoners nevertheless seems to object to one of his associates lecherously forcing the female scientist to strip herself in front of him and orders him to put clothes on her and place her with the rest of the prisoners. He's occupied elsewhere when the actual rape attempt happens, however.
- Shameful Strip: A female scientist who's being held captive by the guards is forced to strip down by a lecherous guard, who then comments on her... grooming habits. His companion objects when he walks in on this, and gives her some clothes to cover herself up.