Rivals is a befriending system featured in Conduit 2.
In addition to the Wii's use of Friend Codes, the game will feature a "Rivals System" in which a player can send friend requests to other players in the lobby of a matchmaking match to add to their friends list without having to exchange Friend Codes. Advantages of befriending players with this system includes being able to chat with eachother, and playing with a rival for the first time earns an achievement once.
Up to 64 friends can be listed.
References
1. Interview with Conduit 2's Lead Designer http://screwattack.com/videos/Conduit-2s-Lead-Designer