"A Christmas Story" is based on the book "In God We Trust: All Others Pay Cash" by humorist and author Jean Shepherd. The book was published in 1966 and was adapted into a movie in 1983, which has become a beloved holiday classic. The movie tells the story of Ralphie, a young boy growing up in the Midwest during the 1940s, who dreams of getting a Red Ryder BB gun for Christmas. The movie is filled with memorable scenes and characters, including Ralphie's father's leg lamp and the "you'll shoot your eye out" warning.