The film follows a group of four contestants (a husband and wife on the verge of divorce, and a pair of sisters) on a reality television game show who are locked in the titular "Red Room" to torture each other, with the last person standing winning one million dollars. The contestants are made to pick cards which decide who will pick the torture, who will apply it, and who will be the victim. The tortures chosen start off relatively mild, but gradually escalate into extreme sadism and sexual abuse.