Play is "an occasion of pure waste: waste of time, energy, ingenuity, skill, and often of money." It is also an essential element of human social and spiritual development.<BR>In this study, Roger Caillois defines play as a voluntary activity that occurs in a pure space, isolated and protected from the rest of life. Within limits set by rules that provide a level playing field, players move toward an unpredictable outcome by responding to their opponents' actions. Caillois qualifies types of games and ways of playing, from the improvisation characteristic of children's play to the disciplined pursuit of solutions to gratuitously difficult puzzles. He also examines the means by which games become part of daily life, ultimately giving cultures their most characteristic customs and institutions.