In 2014, the New Founding Fathers of America, a totalitarianism political party, are voted into office following an economic collapse. They pass a law that sanctions an annual "Purge": for 12 hours each year all crime, including murder, arson, theft and rape, is legal, except against government officials, and all emergency services are unavailable until 7 am. By 2022, the United States has become virtually crime-free and the unemployment rate has dropped to a rate of 1% because of the Purge.
On March 21, 2023, the media credits the annual Purge, a 12-hour period wherein all crimes are legal without authorities intervening, as an economic success. Everywhere, people prepare to either barricade themselves indoors or commit acts of violence. The nation's impoverished population is no longer seen as people, but as living garbage, whom the wealthy denounce as only living to serve their needs. However, before the sixth annual purge begins, a successful anti-purge Resistance movement led by Carmelo Johns and his partner, the Stranger from the The Purge hijack government feeds to denounce the New Founding Fathers and their actions.
A young Charlene "Charlie" Roan and her family are tied up by a masked purger. He taunts them with his "purge playlist", and then tells them they will play a final purge game called "Mommy's Choice." He then proceeds to kill the rest of Charlie's family and leaves her as the only survivor of her family. Eighteen years later, Roan is a United States Senator campaigning for the President of the United States, promising to end the annual purge nights. Former police sergeant Leo Barnes is now head of security for Roan. The New Founding Fathers of America's (NFFA) leader, Caleb Warrens and their candidate, Minister Edwidge Owens, view Roan as a threat; in the guise of regaining the public's trust, revoke immunity for rank 10 or higher government officials to kill her on Purge night.
A crazed drug addict named Skeletor discusses his dark thoughts, including his desire to "purge" and unleash his hatred on other people. A psychologist tells Skeletor that he will soon be able to.
During a 12-hour period when all crime - including murder - is legal, a group of seemingly unrelated characters cross paths in a city in an altered America ruled by a totalitarian political party. While the clock winds down, some will fight, some will hide, others will embrace what it means to purge to its fullest extent - whether for revenge, personal gain, protection, or unadulterated glee. As each character is forced to reckon with his or her past and plot how to better their futures, they soon discover how far they will go on Purge Night.
All the rules are broken as a sect of lawless marauders decides that the annual Purge does not stop at daybreak and instead should never end.