This film is adapted from real events, and the story takes place at Stanford University in the early 1970s, when a group of college students conducted a research experiment on human behavior. They split into two groups, one playing the role of prison guards, while others played the role of prisoners and began to simulate daily life in prison within 24 hours. It turns out that the person who plays the prison guard becomes violent in the simulated prison situation, while the person who plays the prisoner conspires to revolt. The experiment was stopped soon, but its research results have been concerned by people for many years and caused widespread controversy.