If the possibility of "creative surprises" depends on ignorance about the logical consequences of a game move, it seems that this would be best modeled as an asymmetric information problem.

It's interesting to note that the usual "Dutch-book" arguments for subjective probability break down under asymmetric information - the only way to avoid losing money to a possibly better-informed opponent is refusing to enter some bets, i.e. adopting an upper-lower probability interval.

Of course, such upper-lower spreads show up routinely in illiquid financial markets; I wonder whether any connections have been made between rational pricing conditions in such markets and imprecise probability theories like Dempster-Shafer, etc.