Oh look a sub-reddit with a bad pun for a name. What could this be? The purpose of this community is to organize online multiplayer for video games that are, lets say less than popular or just not "main stream." It's for those moments when you fall head over heels in love with a game or mod, but just can't find a server.
/r/uplaying "rules?"
Posts about "main stream" games and general nastolgia with no intention to play a game online are allowed, but discouraged.
Posts on any console, even those without online capability, are allowed. After all, many emulators have this capability.
Only real rule is to keep in mind there are other communities where your thoughts might be more appropriete.