I know that a game has imperfect information if there is an nonsingleton information set, and that defines a situation on which a player can't distinguish between the nodes in the information set. However, I'm wondering if, conceptually, it makes sense that the payoffs can be different, and still the player at the nonsingleton information set can't distinguish between the nodes. For example, consider an extensive form game with imperfect information like the following:

game with a subgame with an infoset with two nodes

Which appears in Game Theory Online. There is an information set with two nodes for player 1 after player 2 choses A or B. Why player 1 can't distinguish at which node she is by the payoffs of, say $l$? If she recognizes that the payoff of $(0,0)$ corresponds for $l$ after $A$ and $(2,4)$ for $l$ after $B$, doesn't this disambiguate the situation?

  • 3
    $\begingroup$ She moves before payoffs are realized, so she cannot use this payoff information. $\endgroup$ – Michael Greinecker Mar 8 at 6:30
  • 3
    $\begingroup$ Also, the title is about incomplete information, but the question is about imperfect information. $\endgroup$ – Michael Greinecker Mar 8 at 8:08
  • $\begingroup$ Thanks. And yes, my mistake, I meant "complete and imperfect". $\endgroup$ – jealcalat Mar 8 at 12:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.