It would also be helpful to instruct people to download the game using the offline installers. The main GOG download link gives you GOG_Galaxy_Fallout.exe which I have no idea what to do with. I had to dig around to find the offline installer buried under several menus.

I'm a mac user so I can't really run the offline installer. My experience (and I bet these screens change often...) is that the default option is to download an offline installer, but there's also a list with two items that lets you download the 2 files I mentioned.

Following these instructions did succesfully get me the files for the game. However the community Fallout app doesn't start. It just keeps bouncing and says Application not responding after a while. I'm using Sonoma 14.4.1. Other than that I have no weird stuff installed. Anyone know what could be wrong?

In addition to issues with the innoextract flag, the official instructions don't make sense for the steam download which doesn't give you an installer but rather it gives you a couple .DAT files and a .cfg file. The instructions which worked for me are (EDIT: I published these instructions with additional screenshots here:

1. Install the Steam macOS client
2. From the terminal, run Steam with the -console flag: /Applications/Steam.app/Contents/MacOS/steam_osx -console. This will give you a new CONSOLE tab at the top beside the STORE, LIBRARY, etc tabs.
3. Find Fallout on steamdb.info and grab the app ID and the depot ID (for me the app ID was 38400 and the English language depot ID was 38409--you can find more depots on the 'depots' tab on the left of the page)
4. In the CONSOLE tab of the Steam client, run download_depot <appid> <depotid> (e.g., download_depot 38400 38409). After a moment, the console should report that the download has begun and when it completes, it will print the download path.
5. Optionally move or copy the depot directory somewhere more accessible, like ~/Games/Fallout
6. Download the Fallout CE installer (the macOS .dmg file) from the Fallout CE releases page if you haven't already. Running the installer should open a Finder window with just the Fallout Community Edition app; drag that into your depot directory (e.g., ~/Games/Fallout).
7. Open your depot directory in a Finder window and double-click the Fallout Community Edition application to start the game.

This looks like this to me:

And then I get this error:

@tofagerl Did you download from Steam from the instructions I provided? When I downloaded from Steam I only had a MASTER.DAT, a CRITTER.DAT, and a fallout.cfg file...

In case it is helpful, I published the same instructions but with screenshots on my blog: https://blog.weberc2.com/posts/fallout-macos.html

@weberc2 No, I used Whisky and assumed I just did the same operation in a different way.
I'll try it your way.

@tofagerl I'm still surprised you got that error seeing as how your directory has all the same files as the Steam download... 🤔

It seems to have more files, actually. Oh well.
It works now - I just downloaded it with the console thing, and verified that it started up.
I'm at work, so I can't really start playing yet :D

Thanks for your help!

Thanks @guy4261 I ran into the same issue. Got as far as actually extracting the offline installer instead of the GOG installer, but having to drag the .app file into the folder didn't click for me yet, haha. Works now :)