# What Is a Utility in Game Theory?

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Martha Robinson

Game theory is a branch of mathematics that deals with decision-making in situations where multiple players are involved. In such situations, the outcome of a player’s decision is not only dependent on their own choices but also on the choices made by other players. In game theory, the term “utility” is used to describe the satisfaction or benefit that a player derives from a particular outcome.

## Defining Utility

Utility is a concept that was introduced in economics to describe the level of satisfaction or happiness that an individual derives from consuming goods and services. In game theory, utility takes on a broader meaning and refers to any measure of value or benefit that a player receives from an outcome.

The concept of utility is central to game theory because it allows us to quantify the preferences of players and predict their behavior in different scenarios. By understanding what outcomes provide the most utility for each player, we can make predictions about which strategies they are likely to choose.

## Types of Utility Functions

In game theory, a utility function is a mathematical expression that assigns numerical values to different outcomes based on how desirable they are for each player. There are two main types of utility functions: ordinal and cardinal.

An ordinal utility function ranks outcomes in order of preference without assigning any specific values to them. For example, if a player prefers outcome A to outcome B and outcome B to outcome C, then their ordinal utility function would rank A higher than B and B higher than C but would not assign any numerical values.

A cardinal utility function assigns numerical values to different outcomes based on how much value they provide for each player. For example, if an outcome provides twice as much value as another outcome, then it would receive twice as high a numerical value in the cardinal utility function.

## Calculating Utility

Calculating utility in game theory involves determining how much benefit or satisfaction each player derives from different outcomes. This can be done by asking players to rank outcomes in order of preference or by assigning numerical values to outcomes based on the amount of benefit they provide.

Once utility values have been assigned to different outcomes, we can use them to predict how players will behave in different scenarios. For example, if a player has a higher utility for outcome A than for outcome B, then we can predict that they are more likely to choose strategy A over strategy B.

## Conclusion

In summary, the concept of utility is essential in game theory because it allows us to quantify the preferences of players and predict their behavior in different scenarios. Calculating utility involves determining how much benefit or satisfaction each player derives from different outcomes and using this information to make predictions about their behavior.

By understanding the concept of utility, we can gain valuable insights into decision-making in situations where multiple players are involved. Whether you’re studying economics, game theory, or just interested in understanding human behavior, the concept of utility is a powerful tool that can help you make sense of complex decision-making processes.