I'm debating right now between the GOG and Steam version.

If I want to play with a friend online, how does it work on GOG, if he also has the GOG version? And what if he has the Steam version?

Anyone tried it online yet ?

I'm also interested in knowing this info!

Basically the same system they used in DOS:2. One player hosts a lobby which generates a "Server ID". This ID you send your friend who then joins you via "Direct Connect". This did work cross GOG and Steam for DOS:2 and I assume the same applies here.

Can't tell you certain till after this weekend when my friend (who likely gets it on Steam) and I have the time to play.

Since the game is in alpha right now, and the EA version of the game only includes the first chapter, I'm not sure the multiplayer is something reliable at this point.

Cross-saves, cross-play between future platforms and Twitch extension will require a Larian account. All info here.