People are often engaged in situations that require they play by the rules. In business, sports, and even in personal relationships, we agree to play fair, fulfill our contracts, and act in good faith.
However, there are some forms of play that involve solitary musings, games of self against chance, or isolated bits of secret whimsy. Because they have no impact on others, we need not play by the rules.
Still other kinds of play require that at least one other person be involved, but even then, there may not be any predetermined rules to follow, and no need to remind each other not to be so serious because “it’s only a game.” The best examples are conversation and lovemaking.
Intimate involvement between two people is a process of discovering what the rules between them are to be.