-Extrinsic knowledge refers to information that comes from the outside.
-Imperfect information refers to a situation in which a player doesn't know all the information needed from the beginning of the game when he has to do something.
-Perfect information refers to a situation in which a player knows all the information needed from the beginning of the game when he has to do something.
-Intrinsic knowledge refers to the information that a person knows without realizing it.
According to the definitions, the kind of challenge that has been describe in this situation where the weakness of the demon is exposed through trial and error is imperfect information.
