Duck on a rock is a medieval children’s game that combines tag and marksmanship (via throwing accuracy).
James Naismith used the game as an inspiration when he developed the rules of modern basketball.
The other players throw stones at the "duck" in an attempt to knock it off of the platform.
[1] In 2006, James Naismith's granddaughter discovered his handwritten notes and typewritten rules among boxes of documents in her basement.
[2] In the documents, Naismith recalled playing "duck on a rock" as a child and used its rules as inspiration when he developed the game of basketball in 1891.