Sports, physical contests pursued for the goals and challenges they entail. Sports are part of every culture past and present, but each culture has its own definition of sports. The most useful definitions are those that clarify the relationship of sports to play, games, and contests. “Play,” wrote the German theorist Carl Diem, “is purposeless activity, for its own sake, the opposite of work.” Humans work because they have to; they play because they want to. Play is autotelic—that is, it has its own goals. It is voluntary and uncoerced.