Ok lets say you have your game with OINC but it's a 4 player game, so only 2, 3 or 4 people can play at a time.
I'd Imagine you should do it like this- Lets say you start in a general chat room with a "host game" button & a list of games to join, at any time you can create or join a game which sends you to a channel but only if there are less than 4 people in that channel & that game hasn't started yet and the host can press start so they can blow each other up. (Or In other words, like battle.net).
1) How do I create a list of availible Games?
2) How can a player create a Channel?
3) How do I limit the number of players in a specific Channel? (not all, I dont want a limit on the entry chat room).
4) How do I check to see if a game hasn't begun yet and people are still joining?