Play is only possible with the presence of rational activity. A necessary condition for the start of the game is an excess of forces (energy). Play is a resource-intensive behavior. Games that are based on agonistic behavior reflect the species-specific behavior of adult individuals. The ability to perform game-like actions is innate. The main types of games: - SOLITARY GAMES Actions involving the use of the body's physical capabilities (jumping, running, kicking, climbing trees, sledding down a hill in winter). - IMITATION OF HUNTING, AGGRESSIVE, SEXUAL, PARENTAL, AND OTHER FORMS OF BEHAVIOR Different scenarios are implemented: how to approach one's own and others, interact with a sexual partner, children, objects of hunting, escape from danger (a predator), attack, fight, win, yield, obey, dig, build, hide, etc. For game behavior, the change of roles is important. A person thus checks not only his own actions but also learns what the other party can do in contact. Play allows breaking, minimizing individual (personal) distance, entering into physical contact with a partner, learning, feeling, understanding what another person's body is like, what can be expected from him, and how to behave with him. Sometimes, a weaker, clearly losing partner is allowed to win in order to prolong the time of enjoyable contact. Sounds, facial expressions, and body movements signal that no harm will be done. - OBJECT GAMES Games using various material objects - toys. Inanimate and living (dragging a cat by the tail). - SOCIAL GAMES Games developed by society, aimed at the organizational, communicative, intellectual, professional, and creative development of a person. As the game becomes more complex, the requirements for communication skills, brainpower, and other resources increase. Games are designed to develop memory, quick wit, reaction speed, and erudition. They play a significant role in social adaptation, preparation for adult life, and increasing competitiveness in the modern world. With the help of play: - the world is explored under conditions where it is possible to return the situation to its original state; - existing abilities and opportunities are tested; - the rules of ritual behavior are mastered: predator (hunter) - prey (one runs away, the other searches, catches, catches), mating partners (rituals of acquaintance, courtship, accompaniment, intimate contact, rivalry, building a house are practiced), parents-children (one as if feeds the other, protects, calms, warms, dresses, cleans, carries from place to place); - the execution, debugging, adjustment, and training of behavioral programs are checked; - the systems of control of the organism are adjusted in different situations; - a preliminary identification of hierarchical status is carried out, the ability to implement it (lead, obey) and change it is acquired, a habit of dominance, subordination is developed (the foundations of hierarchical relationships are laid). Game struggle is emotionally positive and has an integrating effect. The most important role of play is that innate elements of social behavior are integrated into a whole and refined to meet the demands of the environment.