Playing Steam games off a USB
Are you playing games on Steam? Are you having problems with those games loading from an external USB drive? I have a solution flowchart for you!
This combines several tips and tricks. I'm specifically on a Mac, which seems to be the cause of at least some of these problems, but not all of them.
The situation: I wanted to play Baldur's Gate 3 and Cyberpunk 2077.
Problem: I don't have a very big hard drive, and both of these games don't fit at the same time. So, I normally use a USB drive. Normally this works perfectly fine.
However this time, trying to install and play these games on a USB drive was giving me issues where the games either wouldn't install directly on the USB (Cyberpunk 2077), or wouldn't load properly if installed directly on the USB (BG3).
For example: the icon for BG3 would appear, and bounce around like it was opening, but nothing would happen. At one point, BG3 would load to the Launcher, I could click to open the game, I would get the first splash screen, but then it would just go black.
Dragging and dropping the game folders from my computer to the USB didn't work. The .exe / .app files got messed up somehow. These problems with the USB were apparently all due to Mac permission issues.
On top of that though, even when installed on the main hard drive, I was having an issue where trying to open BG3 via Steam lead to a "verifying game files" loop. This is not a Mac-specific issue.
So here is the full solution! Note that you don't need to do the whole opening via the .exe or .app files UNLESS you get the "Verifying Program Files" loop.
Running Steam games off a USB:
Install the game on your main computer's hard drive using Steam.
Open the game via Steam to make sure it's working. Close the game.
Use Steam to transfer the game's files to your USB drive. This is under the game's Manage > Properties > Installed Files. If this option is not showing up but the USB is connected, go to main Steam Settings/Preferences > Storage and make sure your USB is added to Steam. Then, restart Steam and try again.
Wait for the files to transfer.
Once the game is fully transferred, you should be able to play the game via Steam off of the USB drive!
Fixing the "Verifying Program Files" loop:
Close Steam completely. Give it a good long time for all background processes to stop, too.
Navigate to the game's folder and load the game via the .exe or .app file. You can use Steam to find the folder, for me it was in a hidden Library directory. Just make sure Steam is closed before you load the game!
Make sure the game loads fully, then close the game.
Open Steam again, and now when you open it via Steam it should work fine.












