Hello, sorry for the noob question.

As I understand, GOG setups are fully offline and games don't require connecting to servers.

I'm looking on the games I own choosing some to install and play, and I see that some of them have achievements with % of players who had achieved them.

How are achievements uploaded to GOG servers? Is GOG Galaxy required? Or I just need to normally download the setup files and install it and the game will connect to GOG server and achievements will be uploaded?

They are uploaded through Galaxy. If you don't use it, you won't unlock them.

Not true. I have Galaxy installed but almost always use offline installers, however some games (e.g. Craft the World, Banner Saga, others) have unlocked achievements though they've never had anything to do with Galaxy. Even if you only use offline installers, the games themselves still include Galaxy libraries which they presumably use for achievements. Some of the more carelessly coded games like Craft the World will also take an excessively long time to start up if you're not online, as they keep trying and failing to make an internet connection before eventually giving up.

You need to use Galaxy. Games themselves won't connect anywhere, it's the GOG client.

There can be some cases where you can try to "achieve" things on a standalone installation, where you first play the game and then transfer savegame files to a computer that has Galaxy and then claim the achievements from there. At least on Steam, with some games you can do that, with some others, you can't. This method works, if it works, with recordable achievements like high scores, but anything that isn't recorded and is only monitored during gameplay (like possible playing hours achievements) won't work like that.

Your understanding is not fully correct. If you want Achievements and/or Cloud Saves and/or gameplay time tracking on your GOG games, then you need to use GOG Galaxy for your "GOG setups."

And in addition to that, some GOG games have DRM content which is gated behind the Galaxy client, so if you don't use Galaxy, then you can never access all of the content in those GOG games.

Perhaps that was true once, but, sadly, it's not widely true any more...

I never have Galaxy running in the background, never used it to launch a game, and the achievements still are activated. Note that only some games do this; e.g. I played Surviving Mars quite a bit and it didn't record any achievements.

Hmmm, if it is only for some games, then I'm not sure. I am pretty sure I encountered both cases but don't know which was which then.

Thanks for all explanations. It seems GOG should better clear out how their system works.

So, GOG offers offline installers for all games, but for recording play time and achievements we need Galaxy?

There are divergent explanations on whether it's enough to have Galaxy running and we can still use offline installers, or if we need to install games and run games from it.

Recording play time requires Galaxy. Some games record achievements without it, but it's not consistent, so if you want to be sure, use Galaxy. (This is, of course, specifically referring to Galaxy achievements; some games have in-game achievements that are not tied to a client and may even be necessary for progress, e.g. Into the Breach.)

Hello,

- Games installed with an offline installer will automatically be found by the Galaxy client, no need to redownload them.
- You need to use GOG Galaxy and be connected to the internet to unlock achievements and/or tracking your playtime.
- Games downloaded and installed with GOG Galaxy can always be played offline and without the client ( exactly like the offline installers )

GOG Galaxy also offers Cloud Save support which is pretty useful :)