Hide-and-seek or hide-and-go-seek is a children's game in which a number of players conceal themselves in the environment, to be found by one or more seekers. The game is played by one player chosen at random (designated as being "it") counting to a predetermined number while the other players hide. After reaching the number, the player who is "it" attempts to locate all concealed players. The game is an example of an oral tradition, as it is commonly passed down by children to younger children.

http://en.wikipedia.org/wiki/Hide-and-seek