duck on a rock

noun
  1. a children's game in which one player stands guard over a stone on a rock while the other players attempt to knock it off by throwing another stone in turn: if the thrower is tagged by the guard while trying to recover the stone, the two players then change positions.
Also called duck on the rock, duck on drake.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018