There are such things as zero-sum games. Chess is one of them. One player’s victory means the other’s loss. The point is to beat your opponent, not cooperate with him.
On the other hand, an example of a non-zero sum situation is when say, Japan hopes that America’s economy will soon pick up so that Americans will start buying Japanese goods again. A prosperous America is usually good news for other nations.
There is a tendency for people to think that the job market is zero-sum. You sometimes hear people say that there are no jobs out there. That some people are practically unemployable, even if there were jobs out there, doesn’t seem to occur to some people. Even so, to an extent they are right: when someone takes a job then there is one less job for everyone else. However, it isn’t quite that simple. The job market is dynamic, not fixed. When the economy is doing well, companies thrive and expand, thereby creating new jobs. Therefore someone taking a job might just create another job somewhere else.
I remember when I lived in Germany many of the board games that my nurturing, progressive liberal German friends played were of the non-zero kind. The winners were the ones who best cooperated with other players. I never joined in these games because they sounded a bit lame to me. I like games where you annihilate the opposition, not help him.
Sometimes my Japanese students confuse zero and non-zero games. When they are playing musical chairs during the end of term party it is not unusual for the last two students to politely offer the solitary chair to each other when the music stops. Cooperating instead of competing at zero-sum games like musical chairs clearly renders them pointless and no fun at all.
I think some people also confuse zero with non-zero attitudes when it comes to Islamists, criminals, Gypsies and welfare spongers, all groups I consider better placed in the zero-sum category. It seems to me that the more you cooperate with these groups, the more likely it is that things will go badly for you and your kind. I see us in a zero-sum conflict with them.