In a game with incomplete information, players do not possess full information about their opponents. The structure of the game and the payoff functions of the players are commonly known but players may not see all of the moves made by other players.
A typical example is an auction: each player knows his own utility function (valuation for the item), but does not know the utility function of the other players.
- If something is worth more to me than to you, but you don’t know about it, you don’t know what to expect from me
Complete vs Perfect Information
There is a big difference with games of Imperfect Information. I am still trying to wrap my head around this.
A game with complete information may or may not have perfect information, and vice versa.
Poker is an imperfect but complete information game
- Games with complete information generally require one player to outwit the other by forcing them to make risky assumptions
Examples of games with incomplete but perfect information are conceptually more difficult to imagine, such as “Ticket to Ride”
- Games with perfect information generally require one player to outwit the other by making them misinterpret one’s decisions