A reputation of an on-line gamer is calculated in accordance with feedback about the gamer provided by other players. The gamer's reputation is determined in accordance with the number of players the gamer has encountered via game play, the number of players who have indicated that they prefer to play with the gamer again, and the number of players who have indicated that they prefer not to play with the gamer again. Parameters used to determine the gamer's reputation can be weighted and/or decayed to allow a more dynamic and temporally accurate determination of the gamer's reputation. Players can observe other players' reputations.