Competitive games form a distinct category of games. They are in contrast first of all to the sensory-motoric games of small children, who play with a foot, utter inarticulate sounds or throw things on the floor for the simple pleasure of acting upon the surrounding world, games of make-believe or acting out a fictitious situation, and emotional games, the best known of which are those whose object is to make you dizzy or lose balance, and sexual games.

Philosophers who have studied games to determine their nature have evidently established two hypotheses: on the one hand, that all games can be studied collectively, as though the essence of the game were common to all, and on the other hand, that the answer to the problem lies in the subject, or who plays, and not in the game itself considered as an object. The question then is to determine the psychological, biological or social reasons that induce men or animals to play, the inclinations that are involved, but not the external structures to which games must conform in order to please or to be adopted.