1. A method comprising: identifying, by a client device, a plurality of contacts of a user, wherein the user is a player of a first game associated with a game networking system, and wherein the plurality of contacts are not players of the first game; collecting contact attributes for each of the plurality of contacts from one or more contact attribute sources, wherein the one or more contact attribute sources include at least one social network service separate from the game networking system; requesting, from a server device hosted by the game networking system, a first configuration data table for the first game, wherein the first configuration data table includes a plurality of contact scoring rules of the first game, and wherein the plurality of scoring rules of the first game differ from scoring rules of a second game of the game networking system; scoring the collected contact attributes of each contact of the player according to one or more updateable rules of the first configuration data table, wherein the plurality of contact scoring rules of the first game are used to score each contact based on attributes of the respective contact; ranking, in a contacts ranking list, each contact based on a respective score; selecting a portion of the contacts ranking list; and displaying, on the client device, a selectable instance of each contact included in the selected portion of the contacts ranking list; and transmitting an electronic invitation to each selected contact, in response to selection of the selectable instance by the user, wherein the electronic invitation enables the respective contact to perform a collaborative game session of the first game with the user via the game networking system, and wherein in response to selection of the electronic invitation, the game networking system causes the display of the collaborative game session to be customized based on the attributes of the selected contact.