There is, accordingly, to a rule - a vague term, incidentally - often both a factual aspect, concerning the normal or regular or most common course of events or actions, and an evaluative aspect, such as in morals or logic or mathematics (etc.), that amounts to the thesis that following the rule is the right, done, valid or proper thing, in the circumstances.

In the case of logic and mathematics, there are rules of inference, but most consciously done complicated human things come with some set of rules for doing such human things, that often are less well articulated and clear than those in logic and mathematics, and sometimes are not stated at all but only tacitly understood, and that may take many years to acquire and learn to apply properly or well. (See: Education)

And all manner of games and play humans engage in, of all kinds, tend to involve some characteristic set of rules for these games or ways of playing, to which the same applies.

Likewise, the law, ethics and morals, and ordinary human social behavior, politenesses, etc. also involve rules, and the socially more or less enforced duty to play by these rules, when this is appropriate for a member of the society that has such rules.