Zero sum game

Its a situation where one person’s gain is another person’s loss, so that the net benefit is zero.

Examples of Zero sum game include games like Chess. But in this context both the players have consented to lose in the game and take the loss for the mutual benefit of experience or challenge.

Poker and gambling can also be looked as a ZSG because the sum of the amount won by one player amounts to the combined losses of the other players.