Nash equilibrium
A Nash equilibrium is a state in a game where no player can do better by changing their strategy alone, given what everyone else is doing. It’s a stable standoff — not necessarily the best outcome for anyone, just one no one can unilaterally improve on.
How it works
To find the equilibrium, ask of each player: given everyone else’s choices, would they want to change theirs? When no one would, you’ve found a Nash equilibrium — the predictable resting point of strategic interaction, even when it’s collectively bad.
A situation can be locked in place precisely because no one can fix it alone.
How to use it
- Predicting where a strategic situation will settle, even if the result is suboptimal.
- Understanding why bad-but-stable outcomes persist (no one can fix it alone).
- Designing rules so the equilibrium players settle into is a good one.
Worked example
In the prisoner’s dilemma, both confessing is the Nash equilibrium: given that the other confesses, each is better off confessing too, so neither will switch — even though both would be better off staying silent. The stable outcome is the bad one.
Where it fails
A Nash equilibrium says nothing about whether the outcome is good, fair, or efficient — only that it’s stable. Games can have multiple equilibria, and real people don’t always play to equilibrium, so it predicts resting points, not morality or guaranteed behaviour.
- Computing the equilibrium is often intractable once a game has many players or moves, so the concept can be unusable in practice.
- It assumes rational players who share full knowledge of the payoffs, a condition rarely met outside a textbook.
- It identifies resting points but says nothing about how players get there or which of several equilibria they land on.
The counter-model: Schelling point — When a game has several equilibria, the Schelling point predicts which one people actually coordinate on, filling the gap Nash leaves.
How to apply it, step by step
- Map the players, their options, and each combination's payoffs.
- Find the states where no single player can improve by changing alone.
- Note whether there is one such state or several.
- Check whether real players have the information and rationality the concept assumes.
- Treat the equilibrium as a likely resting point, not as a good or fair outcome.
The deeper point
Its sobering insight is that stability and desirability are different things: a situation can be locked in place precisely because no one can fix it alone, even when everyone would prefer a different outcome. Escaping a bad equilibrium almost always requires coordination or changed rules — never just one person trying harder.
Frequently asked
- What is a Nash equilibrium?
- It’s a state in a game where no player can improve their outcome by changing strategy alone, given what everyone else does. It’s a stable standoff — the predictable resting point of strategic interaction.
- What is an example of a Nash equilibrium?
- Both players confessing in the prisoner’s dilemma: given the other confesses, each is better off confessing, so neither will switch — even though mutual silence would be better for both. A stable but suboptimal outcome.
- Is a Nash equilibrium always the best outcome?
- No. It only means no one can do better by acting alone — it can be collectively terrible (as in the prisoner’s dilemma). Games can also have several equilibria, some far better than others.
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Cite this page
ReadGlobe. (2026). Nash equilibrium. https://readglobe.com/model/nash-equilibrium/
"Nash equilibrium." ReadGlobe, 29 May 2026, readglobe.com/model/nash-equilibrium/.
Primary source: Wikipedia
Editorial synthesis © ReadGlobe 2026, drawing on the mental-models tradition (Charlie Munger, Farnam Street) and the primary sources for each model. · Last reviewed 2026-05-29.