Two-person Constant Sum Games

In Part I all decision problems were formulated from the point of view of a single actor. He was not necessarily an individual: he could be a corporation, an institution, or a state. His ‘singleness’ was expressed in a set of goals, values, utilities, and the like. To be sure, the outcomes of his decision depended not on these alone. Usually another agency, which could be called Chance, acted like a decision-maker in the sense of choosing among ‘states of the world’ resulting from events over which the actor had no control, for example a spin of the roulette wheel, the market price of a commodity, and the like. But this agency was not a true actor in the sense used here, since it received no payoffs and so was assumed to be indifferent about the states of the world. To be sure, there are people who believe it will rain just because they left their umbrella at home or that the sun will shine just because they took it along. But such beliefs can be credited to lapses of rationality.