In game theory, zero-sum game is a situation when advantage on one side means an equal loss on other side. Most of card and gambling games are build in this way.

Derived from games, the zero-sum thinking creates some misconceptions and cognitive biases about real life. Here are some examples:

• Lump of labour fallacy -- a belief that immigration increase unemployment
• Principle of limited good -- a theory held mostly in traditional societies, about how amount of every "good" in the world is constant
• Golden billion -- a conspiracy theory that a cabal of global elites are pulling strings to amass wealth for the world's richest billion people at the expense of the rest of humanity

In reality zero-sum is almost never the case. The wealth is created by people, and total amout of it depends on labor efficiency, which increases over time.

Strong belief in zero-sum can trigger competitive behavior in individuals, reducing the overall efficiency of the society, which ironically reduces the wealth growth. This is an example of self-fulfilling prophecy