Consider also that when a zero-sum game is embedded in a positive-sum one, often the most effective way to negotiate is to threaten to walk away from the positive-sum game if you don’t get a bigger share of the spoils (e.g. threaten to leave the job if you don’t get a rise). The simplified version is the ultimatum game: https://en.wikipedia.org/wiki/Ultimatum_game.
This also means that holding a positive-sum trade sacred has the side effect of freezing the zero-sum part of it to the status quo.
Consider also that when a zero-sum game is embedded in a positive-sum one, often the most effective way to negotiate is to threaten to walk away from the positive-sum game if you don’t get a bigger share of the spoils (e.g. threaten to leave the job if you don’t get a rise). The simplified version is the ultimatum game: https://en.wikipedia.org/wiki/Ultimatum_game.
This also means that holding a positive-sum trade sacred has the side effect of freezing the zero-sum part of it to the status quo.