In accordance with one or more aspects, for a particular user one or more other users associated with that particular user are identified based on a social graph of that particular user. An avatar of at least one of the other users is obtained and included as a non-player-character in a game being played by that particular user. The particular user can provide requests to interact with the avatar of the second user (e.g., calling out the name of the second user, tapping the avatar of the second user on the shoulder, etc.), these requests being invitations for the second user to join in a game with the first user. An indication of such an invitation is presented to the second user, which can, for example, accept the invitation to join in a game with the first user.