Steam?

[Marie]

Do I have to use Steam to play? I'd prefer to not use it.

 

[Lew Zealand]

Do I have to use Steam to play? I'd prefer to not use it.

No you can buy SDV from GOG.com for PC/Mac and not even need a launcher to run it. You can get a standalone downloadable installer from GOG but I think you need to use launchers like Steam (or GOG's Galaxy client) for multiplayer.

 

[FilthyGorilla]

You can even just buy it off steam then delete steam. You'll still have the game to run though you may need to redownload it for any updates. Besides patches in the next couple days though there won't be any major updates for years to come presumably, so you should be fine (just jot down your password for a possible future update)