Yet there are also clear limitations to game theory. Game theory makes some critical assumptions: it assumes a unitary state, in which internal factors play little role in determining a state's preferences. It assumes that the unitary state acts rationally, that states choose the best overall option available. It gives arbitrary payoff structures in advance, whereas in reality states may not know the relative values attached to their various choices or those of the other side. It assumes that the game occurs one time, although most realize that much of international relations is really an extended set of games between the same actors. Thus, the outcome of multiple iterations—in which knowing the choice an actor made at one point in time helps each side to predict the other's choice at a subsequent time period—may be quite different from the one-time encounter. All of these criticisms are key points made by neoliberal institutionalists.