Well, this has really been on my mind for some time now. The Video Games forum is a pretty active forum, and one of my favorites. But I don't see much online gaming going on. (Tournaments, Username/friend code sharing, etc) But maybe if there was an Online Gaming child board, there would be more of it. People could game with each other, maybe have tournaments, make friends for MMOs, form clans and whatnot. It would all be so great. It all seems worthy of it's own forum.
I think it sounds dumb, aside the Metin topic there haven't really been any online game topics here recently, and I don't see how making a child board would encourage people to post topics like "Plz help defiit lvl80 dragon in WoW".
Having a forum for something WOULD encourage members to post in it. I guarantee that if the Bean Bags forum hadn't been made, 30 threads seeking social help wouldn't have been made in a little over a month. They could have always posted them in community, but it isn't directly aimed at social help. The forum is aimed at all-around socialization. It's the same for Video Games. It isn't aimed at online gaming, it's aimed at all-around gaming.
I believe if there were an Online Gaming forum, RMRK would be more inclined to create threads when they want to play someone online.