One night per year, the government sanctions a 12-hour period in which citizens can commit any crime they wish -- including murder -- without fear of punishment or imprisonment. Leo, a sergeant who lost his son, plans a vigilante mission of revenge during the mayhem. However, instead of a death-dealing avenger, he becomes the unexpected protector of four innocent strangers who desperately need his help if they are to survive the night.

Baby Daddy follows Ben, a young man in his early 20s living the life of a bachelor in New York City with his buddy, Tucker, and his brother, Danny. Their lives are turned upside down when they come home one day to find a baby girl left on the doorstep by an ex-girlfriend of Ben's. After much deliberation, Ben decides to raise the baby with the help of his friends and his protective and sometimes over-bearing mother, Bonnie, and his close female friend, Riley.