At specific points in the game’s stories the characters intersect and now they can be controlled by other players, who have been automatically invited into your game. There’s no lobby for it.
It’s the story campaign so you don’t suddenly get thrown into a deathmatch style lobby to hook up with other players. We can choose to let the AI or players take control.
If you don’t want strangers running around in your story then you can opt to just allow friends in, assures Yoshiaki Hirabayashi. The Capcom executive explains the system in more detail on EU PlayStation.Blog.
”The concept of this feature is to have people joining you in real time and seamlessly, so whenever you happen to be at a point where you get to China as Leon, for example, somebody else in the world who’s playing roughly at the same time and they’re also about to get at that point or they’re already there as Jake, he or she will join you.”
”So the idea is more to have a surprise about who’s going to play with you. If want to play with your friends, we recommend, first and foremost, playing with them within the storyline on the co-op, so you’ll be Jake and your friend is Sherry, or you’ll be Leon and your friend is Helena,” continued Hirabayashi-san.
”Of course, if want to play with friends there’s a setting for it, so whenever you come to a chapter or a story section where there’s going to be a crossover, you get a little prompt before that section asking if you want live players joining your game at this point. If you feel like playing on your own or you don’t want to play with a guy you don’t know, you can go with the AI and it’ll be you and three other AI-controlled characters.”
”You can also choose between letting anyone come in or only friends. Of course, because you’re playing in the storyline, it means you’re not going to have a lobby as in a deathmatch, you’re going to get in touch with your friend and tell him to play the same section at the same time with the specific characters, and both will have to set the online co-op to “friends only.””
”We see the concept of this feature as not necessarily being “get your friend on the other side of the crossover”, but “get your friend at the same side as you”.”
There are 3 separate storylines to follow in Resident Evil 6 which releases on Xbox 360, PS3 and PC October 2nd.