# What is iterated elimination of dominated strategies?

## What is iterated elimination of dominated strategies?

Iterated elimination of strictly dominated strategies (IESDS) The iterated elimination (or deletion) of dominated strategies (also denominated as IESDS or IDSDS) is one common technique for solving games that involves iteratively removing dominated strategies.

## Can all games be solved by elimination of dominated strategies?

Iterated elimination of strictly dominated strategies cannot solve all games.

**What is iterated dominant strategy?**

Definition: A player’s strategy is (strictly) dominated if there exists another strategy giving that player a strictly higher payoff for all combinations of strategies by other players. (“There’s something else that’s always strictly better.”)

### What is the outcome of the prisoner’s dilemma?

The typical prisoner’s dilemma is set up in such a way that both parties choose to protect themselves at the expense of the other participant. As a result, both participants find themselves in a worse state than if they had cooperated with each other in the decision-making process.

### What if there is no dominant strategy in game theory?

A game has a Nash equilibrium even if there is no dominant strategy (see example below). It is also possible for a game to have multiple Nash equilibria.

**Does player 1 have a dominant strategy?**

Here • U is a dominant strategy for Player 1, L is a dominant strategy for Player 2, B is a dominant strategy for Player 3, • and therefore (U;L;B) is a dominant strategy equilibrium yielding a payoff of (1,1,2). strategy that performs at least as good no matter what other players choose.

#### Is Nash equilibrium the best outcome?

Unlike dominant strategy, the Nash equilibrium doesn’t always lead to the most optimal outcome, it just means that an individual chooses the best strategy based on the information they have.

#### Can there be two dominant strategies?

Can a player have two strictly dominant strategies? Give an example or prove that this is impossible. No. If si and si were both strictly dominant, si = si, then you would have ui(si,s−i) > ui(si,s−i) > ui(si,s−i) for all s−i, which is impossible.

**Can a strictly dominated strategy be a best response?**

Answer: True. The strategy that strictly dominates it, by definition, yields a strictly higher payoff against all strategies and hence is a better response.

## What is iterated prisoner’s dilemma?

If two players play prisoner’s dilemma more than once in succession and they remember previous actions of their opponent and change their strategy accordingly, the game is called iterated prisoner’s dilemma.

## What is the lesson of the prisoner’s dilemma?

Summary. The Prisoner’s Dilemma teaches many lessons about individuals interacting. A very prominent lesson, the one I treat and call its lesson, concerns standards of rationality. This lesson reveals profound points about the relationship between rationality’s standards for individuals and its standards for groups.

**Can you have Nash equilibrium without dominant strategy?**

### Can there be no dominant strategy?

No dominated strategy can ever be optimal because, by definition of strict dominance, there is another dominating strategy yielding a higher payoff regardless of the other players’ strategies.

### Can there be a Nash equilibrium without a dominant strategy?

Yes, a game can have a Nash equilibrium even though neither player has a dominant or dominated strategy. In fact, every game has a Nash equilibrium, possibly in mixed strategies. The game of Chicken is an example of a game with no dominant or dominated strategies but which has a Nash equilibrium.

**What is difference between Prisoner’s dilemma and Nash equilibrium?**

In the Nash equilibrium, each player’s strategy is optimal when considering the decisions of other players. Every player wins because everyone gets the outcome they desire. The prisoners’ dilemma is a common game theory example and one that adequately showcases the effect of the Nash equilibrium.

#### What if there is no dominant strategy?

If one player has a dominant strategy, the cell in the dominant strategy row or column in which the other player has the maximum payoff is the Nash equilibrium. If no firm has any dominant strategy, identify any dominated strategies and cross those cell out.

#### Is it reasonable for a player to play strictly dominated strategy?

A player has a strictly dominated strategy if that strategy gives them a lower payoff than any other strategy they could use, no matter what the other players are doing. If you have a strictly dominated strategy, expect other players to anticipate you’ll never play it and choose their actions accordingly.

**How do you win iterated prisoner’s dilemma?**

Prisoner’s Dilemma strategies

- Always cooperate, no matter what the other player does.
- Always defect, no matter what the other player does.
- Cooperate unless the other player defects, then punish them to some degree.
- Try to figure out what someone’s strategy is, then play what’s best against that.

## What is the dominant strategy in the prisoner’s dilemma?

The dominant strategy for a player is one that produces the best payoff for that player regardless of the strategies employed by other players. The dominant strategy here is for each player to defect (i.e., confess) since confessing would minimize the average length of time spent in prison.