I have the same problem. Does someone know how to fix this?

Thank you Dr. Schliemann. Tried a number of other things until I looked over the contents of your link. Worked like a charm.

This worked for me on Mojave as well. Thank you!

That blog seems to be dead/gone. What were the instruction/guidance?

Hi, i am also having issues with fallout on Macbook M1 - Mac OS Sonoma

The blog linked previously seems to be gone.. any fix for this?

There is a engine re-implementation for modern operating systems on Github (can't post links here):
fallout1-ce
fallout2-ce

If you have Brew installed you can extract the game from the Windows installer:
brew install innoextract
innoextract setup_fallout_2.1.0.18.exe -I Fallout

Otherwise get the folder from the Mac installer:
Mount it, right click "Show Package Contents". Navigate to Contents/Resources/games. Right click "Show Package Contents" on Fallout folder. Navigate to drive_c/GOG Games and copy Fallout folder.

Download the Mac version from the releases page and copy it to the game folder.

To change the resolution you need to create/change the f1_res.ini or f2_res.ini like written on the Github page.