Different rule systems govern distinct social activities simultaneously. [definitional]
Every language game has a certain grammar, by which I mean the rules that enable a person to participate and thereby to understand that language game. In even the simplest of human situations, there will be many language games, overlaid as it were. Imagine two parents watching their child play a little-league game. The rules that constrain the child from running from first base directly to third are not part of the same system of rules that constrain the father from shouting abuse at the opposing pitcher or that constrain the coach from selling tickets.
XREF: Connects to Wittgenstein's language games and concept of grammar from Philosophical Investigations; also resonates with sociolinguistic notions of situated norms.
Philip Chase Bobbitt, Philip Chase Bobbitt - Refl…, loc. 446