Son Gi-hun is a young man, divorced, up to his ears in debt, and living off his aging mother. Even the money he wins at the races doesn’t stay in his hands for long. One day he meets a mysterious stranger in the metro, who first offers him to play a child’s game, and then hands Gi-hun a sizable sum of money and a business card. Joy turns to despair when he learns that his ex-wife and her new husband are planning to take his daughter to America. He dials the number on the card and becomes the last participant in secret survival games for a prize of forty million dollars. Among his fellow contestants in misfortune are his childhood friend, a bankrupt financier, a gangster, a terminally ill old man, a North Korean defector, a Pakistani immigrant, and many others who are desperate for money.