Piaget² has conducted many careful studies on the evolution of games during childhood, and has suggested that moral behavior consists in a system of rules, and the essence of all morality is to be sought for in the respect which the individual acquires for these rules.³ Piaget thus equates morality, or ethical feeling and conduct, with the individual's attitude toward and practice of various rules. This perspective provides a rational basis for the analysis of moral schemes as games, and of moral behavior as the players’ actual conduct.
Source: wiktionary