No, it does not. Just mathematically the thing you said is clearly false. Suppose I say that, for some system, the return to each player is a function of the

No, it does not. Just mathematically the thing you said is clearly false. Suppose I say that, for some system, the return to each player is a function of the number of players: r(n) = 100 / (n+1). One player makes 50, two players make 33 each for a total of 66, three players make 25 each for a total of 75. Clearly not zero-sum, but I can still move up in the world by killing someone else's cows. One might observe that much of the world is like this; not truly zero-sum, but with payoff matrices that incentivize hurting or helping strangers. Note that almost all traditional microeconomics is this kind of curve-following system, one way or another. I'm not saying that kind of economics is right or wrong, just that it's a very traditional model, worth understanding as a starting point.