It technically still exists in the game properties -> installed files tab, but it doesn't really work. The backup files you get require you to be online to meaningfully restore and will trigger a patch to the latest game version.

Practically speaking it's better to just make a copy of the game install directory manually, gives you a better chance of things working (even though most games require some kind of external tooling for that).

[–] ouch@lemmy.world 1 points 1 day ago (1 children)

What file format does the Steam backup use?

[–] chameleon@fedia.io 1 points 1 day ago (1 children)

For current exports, it's some custom .csm/.csd file combo. Not sure if there's any tools for working with it, seems like it'd be more annoying than just using a normal archive format either way.

[–] ouch@lemmy.world 1 points 19 hours ago

That's bad. I guess if I want to back up my Steam games, it's going to be tarballs.

[–] bjoern_tantau@swg-empire.de 2 points 1 day ago

It's still there. But I never tried it and it probably won't work with DRMed games.

[–] catloaf@lemm.ee 1 points 1 day ago (1 children)

I don't remember that ever being a thing. It's had an offline mode for decades, but for the longest time it never worked properly.

[–] Kolanaki@yiffit.net 1 points 1 day ago* (last edited 1 day ago)

It had a way of packing a game into a CD/DVD when it launched. I used it all of two times. It was slow as fuck. If it still has it, as another commenter suggests, I don't know how to access it.