Non-zero-sum describes situations in which one person's benefit does not necessarily come at the expense of someone else. This differentiates it from zero-sum situations in which one person must lose before another can win. Non-zero-sum situations exist where the supply of a resource is not fixed or limited. It is a case of building a resource rather than dividing it between players. In some non-zero-sum situations, a person can benefit only when others benefit as well.

The concept was first developed in game theory, so that non-zero-sum situations are often called non-zero-sum games regardless of whether the situation is a game.

Table of contents
1 Examples of non-zero-sum situations
2 Complexity and non-zero-sum
3 Popular non-zero-sum games

Examples of non-zero-sum situations

An example of a non-zero-sum situation is the enjoyment of a musical work. You can not enjoy a song only if someone else doesn't enjoy it. If you are enjoying a song, and someone else stops to enjoy it as well, that person's enjoyment does not necessarily detract from your own. Likewise, you do not find a joke funny only if someone else finds it unfunny.

Knowledge is often a non-zero-sum commodity. Someone who invents a better way to raise water from a well does not suffer if people from another village learn his new technique and adopt it for themselves.

Non-zero-sum situations are an important part of economic activity due to production, marginal utility and value-subjectivity.

If a farmer succeeds in raising a bumper crop, he will benefit by being able to sell more food and make more money. The consumers he serves benefit as well, because there is more food to go around, so the price per unit of food will be lower. Other farmers who have not had such a good crop might suffer somewhat due to these lower prices, but this cost to other farmers may very well be less than the benefits enjoyed by everyone else, such that overall the bumper crop has created a net benefit. The same argument apply to other types of productive activity.

Trade is a non-zero-sum activity because all parties to a voluntary transaction believe that they will be better off after the trade than before, otherwise they would not participate. It is possible that they are mistaken in this belief, but experience suggests that people are more often than not able to judge correctly when a transaction would leave them better off, and thus persist in trading throughout their lives. It is not always the case that every participant will benefit equally. However, a trade is still a non-zero-sum situation whenever the result is a net gain, regardless of how evenly or unevenly that gain is distributed.

Complexity and non-zero-sum

It has been theorized that society becomes increasingly non-zero-sum as it becomes more complex, specialized, and interdependent. As one supporter of this view states:

The more complex societies get and the more complex the networks of interdependence within and beyond community and national borders get, the more people are forced in their own interests to find non-zero-sum solutions. That is, win-win solutions instead of win-lose solutions.... Because we find as our interdependence increases that, on the whole, we do better when other people do better as well - so we have to find ways that we can all win, we have to accommodate each other - Bill Clinton, Wired interview, December 2000.

Popular non-zero-sum games

This might be a nice place to have links to non-zero-sum games that can be played by adults and/or children using simple materials (cards|paper|pencils|etc.). Anyone have any such information?

Charades is probably the classic example of where playing is more fun than winning or losing. Just draw up a list of movie titles, book titles, famous persons, historical events, etc. Write each one on a slip of paper and place them into a hat (or other opaque container). Divide into teams. Have the teams take turns selecting slips of paper from the hat and attempt to act out the selected phrase so that their teammates can guess the phrase. A time limit of 3-5 minutes should be placed on each teams turn.