A method to share challenges between users of a social game system is described. The method may include accessing relationship data reflecting a relationship between a first user and a second user, and accessing challenge data in a challenge database. Based on (1) the challenge data and (2) the relationship between the first user and the second user reflected by the relationship data, the challenge data is selectively communicated as part of a challenge about the first user to the second user, with the challenge forming part of a challenge game.