The tokens and rules are an abstraction, but they're not an abstraction of economic and legal factors in the imaginary world. They're abstractions of the social pressures of the native experience in the same way that 'turns' in chess are an abstraction of the process of taking military actions in a war: they impose a well-defined and simple structure on a highly complex system in order to render it playable, and they are at a level of abstraction that means they don't have a clear antecedent in the real-world systems that they describe.