<p>Don't think of Level 0 as a rational strategic option. Rather, consider it as a baseline for the rest of the model. If every level k actor behaves as though others are level k-1, the model recurs to negative infinity without a baseline.</p>
<p>Level 0 is set as that baseline, and it is the purely hypothetical player who essentially isn't playing strategically. In practice, the least sophisticated players are level 1, because they don't consider their opponent's strategy. They are playing as though their opponent is playing randomly.</p>

CC BY-SA 4.0
2022-12-15T17:42:34.690Z
2022-12-15T17:42:34.690Z
Pete Lorenz
<p>A Level-<span class="math-container">$0$</span> player is &quot;non-strategic&quot; in the sense that they do not take into account the possible actions of the other players. Typically, but not necessarily, a Level-<span class="math-container">$0$</span> player is assumed to randomize (uniformly) across her available actions.</p>
<p>For the other levels (<span class="math-container">$k\ge 1$</span>), a level-<span class="math-container">$k$</span> player is assumed to behave as if all other players are of level-<span class="math-container">$(k-1)$</span>. That is, her strategy is a best response to the strategies that would have been used by players of level-(<span class="math-container">$k-1$</span>).</p>

CC BY-SA 4.0
2022-07-25T12:19:06.073Z
2022-07-25T12:19:06.073Z
Herr K.
<p><strong>According to the level-k theory:</strong><br />
<code>Level-k theory assumes that players in strategic games base their decisions on their predictions about the likely actions of other players. According to level-k, players in strategic games can be categorized by the &quot;depth&quot; of their strategic thought. It is thus heavily focused on bounded rationality.</code></p>
<p>And my question is what does <strong>Level-0</strong> mean in the level-k model? How can you choose it wisely?</p>

<microeconomics><game-theory><nash-equilibrium>
Level-0 in Level-k model
Pedro Gómez
# Level-0 in Level-k model

(Asked by: username_0 on 2022-07-25)

**According to the level-k theory:**  
`Level-k theory assumes that players in strategic games base their decisions on their predictions about the likely actions of other players. According to level-k, players in strategic games can be categorized by the "depth" of their strategic thought. It is thus heavily focused on bounded rationality.`

And my question is what does **Level-0** mean in the level-k model? How can you choose it wisely?

**Tags:** microeconomics, game-theory, nash-equilibrium

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## 2 answers

### Answer by username_2 on 2022-07-25. Score: 4 | Accepted answer

A Level-$0$ player is "non-strategic" in the sense that they do not take into account the possible actions of the other players. Typically, but not necessarily, a Level-$0$ player is assumed to randomize (uniformly) across her available actions.

For the other levels ($k\ge 1$), a level-$k$ player is assumed to behave as if all other players are of level-$(k-1)$. That is, her strategy is a best response to the strategies that would have been used by players of level-($k-1$).


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### Answer by username_1 on 2022-12-15. Score: 0

Don't think of Level 0 as a rational strategic option. Rather, consider it as a baseline for the rest of the model. If every level k actor behaves as though others are level k-1, the model recurs to negative infinity without a baseline.

Level 0 is set as that baseline, and it is the purely hypothetical player who essentially isn't playing strategically. In practice, the least sophisticated players are level 1, because they don't consider their opponent's strategy. They are playing as though their opponent is playing randomly.


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