Bought Shadowrun returns on steam.
If I buy the Hong Kong Expansion here on GOG is it compatible with the steam version?

I'm pretty sure all 3 Shadowrun games from Harebrained Schemes are standalone/separate downloads that don't depend on each other to work. I'm not sure if there's some sort of save transfer system between games and if having the games on different platforms would pose any problems.

Since all of the games start from scratch with new shadowrunners I don't see why there would be any way to transfer saves between them. I also believe that the parts from previous games that are used in later games are included in the later games as texture packs or something, so it shouldn't matter that an earlier game is Steam instead of GOG.

The only compatibility you may worry about is that you can import the Shadowrun Returns campaign (dms) into Dragonfall. You can't import either of the first 2 into Hong Kong, though, regardless of where you bought it. As to whether or not you can import the Steam dms into a gog Dragonfall, I would guess that would work, but that wasn't your question anyway.

What Point_Man said is correct: all three games are standalone; you can play Hong Kong, even if you don't own Returns or Dragonfall.

What's the best thing to do for a first time playthrough? Any benefits or negatives to importing the Shadowrun Returns campaign into Dragonfall and playing it through there for the first time? Anything different or inferior about the experience?

Thx for the info guys. I ended up picking up the base game as well since it was only 2 bucks.
Appreciate the intel though!

I suggest looking over this thread. My main reason for doing it was to have only one executable to run for both, as well as any mods I downloaded. HK screwed that one up for me, but it's not a big deal. As to changes, yes, it's a little different, but I can't remember any more what the differences are. DF's interface works a little better, but it also has changes in combat mechanics that may not translate well to dms. If I were you, I'd probably just go ahead and play dms in the original engine first, unless you're already used to df's way of doing things.

Thanks for the link, i'll look through it. I'll probably just play the standalone Shadowrun Returns for my first playthrough just to be safe.

Some modders have migrated the first game into the third (HK) engine, it's called (a little pretentiously :) Dead Man Switch-Vox Populi.

edit: Gog hyperlink labels dislike emdashes