1. a social interaction, organized play, or transaction with formal rules. See zero-sum game.

2. in psychotherapy, a situation in which members of a group take part in some activity designed to elicit emotions or stimulate revealing interactions and interrelationships. In play therapy, games are often used as a projective or observational technique.

3. in transactional analysis, a recurrent and often deceitful ploy adopted by an individual in his or her dealings with others.

4. in gestalt therapy, an exercise or experiment designed to increase self-awareness, such as acting out frightening situations or participating in the hot-seat technique.