Hide and seek is a relatively simple game originating on Earth, where one person counts with their eyes closed while all the other players try to hide from him. When the counter is done, they would go out and try to "seek" the other players.
This game was popular among children on cargo freighters in the 22nd century. In 2151, while Enterprise was docked with the ECS Fortunate, several of the children were playing hide and seek. When one child ran past T'Pol and hid behind an access panel. When the seeker came by and asked T'Pol if she'd seen "Nadine", T'Pol simply responded that she didn't know which child was Nadine. (ENT: "Fortunate Son")
In 2369, to help Amanda Rogers learn to use her new Q-powers, Q played a game of hide and seek with her, while she tried to find him. Some locations he hid at were inside the warp core and on the outside of the ships hull, reminding her not to think on such Human terms. (TNG: "True Q")
Later in 2372, Q once again was involved in a dangerous game of hide and seek, this time with Quinn who was bringing the starship USS Voyager with him. This time Quinn brought Voyager to hide in such places as the Big Bang and miniaturized, hanging from a Christmas tree. (VOY: "Death Wish")