positive-sum game, in game theory, a term that refers to situations in which the total of gains and losses is greater than zero. A positive sum occurs when resources are somehow increased and an approach is formulated in which the desires and needs of all concerned are satisfied. One example would be when two parties both gain financially by participating in a contest, no matter who wins or loses. Positive-sum outcomes occur in instances of distributive bargaining where different interests are negotiated so that everyone’s needs are met.