This implies that the aforementioned rules are well-formed and account for every possible application scenario, and there are times that they are not and do not.
It comes down to the 'level' of rules that you describe. Ex: One would think that behaving unexpectedly (not sticking to the rules) on a battlefield may be logical (is war moral? We could instead take a game of chess). However that abrupt behavior may become a rule by itself.