What is the term for a game in which for every win there must be an equivalent loss?

Asymmetric describes a game or conflict where the participants have unequal capabilities, resources, or goals, but does not specify anything about wins being offset by equivalent losses.

Untenable means a position that cannot be maintained or defended, which is a strategic assessment rather than a term defining the win-loss relationship between players.

Zero-sum is the precise game theory term for any competitive interaction where the total utility is constant - one participant's gain is exactly offset by another's loss, making the net sum always zero. In security contexts, this concept is used to describe attacker-defender dynamics where resources or advantages are strictly redistributed rather than created.

Gain-oriented is not a recognized game theory term; it describes a motivation or objective but says nothing about the mathematical relationship between one player's gain and another's loss.