Can someone who has a gog version of a game play with someone who has a steam version of the game in online games? There are lots of online games and online co-op games out there that are on steam and gog and I wonder if they can join each other’s lobbies and play each other and etc? Or does one need to have a steam copy to join someone else on their gameplay?
Mostly you have to look it up on a per game basis. Probably just Google the game name and "supports cross play between" whatever platforms you want and someone will know