A zero-sum game is a situation in game theory where one participant's gain is exactly balanced by another participant's loss. In other words, the total amount of wealth or benefit remains constant, so any advantage gained by one player comes at the expense of another. This concept is often used in competitive scenarios, such as sports or gambling. In a zero-sum game, the sum of outcomes for all players equals zero. For example, in a game of poker, the money won by one player is equal to the money lost by others. This principle can also apply to various fields, including economics and political science, where resources are limited and competition is fierce.