The series revolves around a contest where 456 players, all of whom are in deep financial debt, risk their lives to play a series of deadly children's games for the chance to win a ₩45.6 billion^[​a] prize. The title of the series draws from a similarly named Korean children's game. Hwang had conceived of the idea based on his own economic struggles early in life, as well as the class disparity in South Korea and capitalism. Though he had initially written it in 2009, he was unable to find a production company to fund the idea until Netflix took an interest around 2019 as part of their drive to expand their foreign programming offerings. All nine episodes were written and directed by Hwang.