A computer-based, multi-player, on-line, game session is capable of being joined while the session is in progress without requiring an invitation from the host of the game session. A player can join the game session via a set of User Interfaces (UIs) provided by the gaming system. The player is not required to contact the host prior to joining the game session. A game session is joinable if slots are available for additional players, the host has not declared the game session private, the player requesting to join the game session is not currently in the game session, and parental controls have not be set preventing the player from joining the game session.