Positive-sum game
A positive-sum game is one in which cooperation can leave all parties better off.
The most important fact about cooperation is that it can make everyone better off at once. A positive-sum game is one where the pie can grow, not just be divided.
A positive-sum game is a situation in which the total of gains and losses is greater than zero, so that cooperation can leave all parties better off. Unlike a zero-sum game, where one side's gain is another's loss, a positive-sum interaction allows the whole to expand, creating value rather than merely redistributing it.
Growing the pie
The defining feature is that the total is not fixed. Through cooperation, exchange, or the combination of complementary strengths, the parties can create more value together than they could apart, so that everyone's share can rise at once. Trade is the archetype: two parties exchange because each values what they receive more than what they give up, so both end up better off and total welfare grows. Specialisation, partnership, and the division of labour are all engines of positive-sum gains.
Why it is so often missed
Positive-sum situations are frequently misperceived as zero-sum, with damaging consequences. The instinct that another's gain must be one's own loss leads people to compete where they could cooperate, to resist trade and partnership, and to leave value uncreated. Much of the case for markets, trade, and cooperation rests on recognising their positive-sum nature, and much economic and political conflict stems from failing to see it. Seeing a positive-sum game as zero-sum forfeits the gains that cooperation would have produced.
Creating and dividing at once
Most real interactions mix the two. There is a positive-sum dimension, how large a total the parties can create together, and a zero-sum dimension, how that total is divided between them. Skilled negotiation works on both: enlarging the pie through cooperation before, or while, bargaining over the slices. Focusing only on dividing risks a smaller pie; recognising the chance to grow it first can leave everyone with more.
The positive-sum game captures the most hopeful idea in economics: that human interaction is not inevitably a struggle over fixed spoils but can be a joint creation of new value. Recognising and building positive-sum relationships, in business, trade, and beyond, is one of the surest routes to outcomes that benefit everyone involved.