I finally got my hands on a Steam Deck and I’ve been trying out a lot of different games on it. Most work great, but sometimes you come up against one or two that either have minor issues, or don’t work at all.

Feeling a dose of nostalgia, I wanted to play the older Star Wars titles on my Deck, well, wherever I take it — that is the point, after all. Unfortunately, Dos Box has not been cooperating while trying to play Star Wars: Dark Forces, a kind of Star Wars-themed Doom clone.

After installing the game, and trying to start it up, it would load the command prompt and then crash back to the Steam UI. I did try a few different versions of Proton to be sure, but it still wasn’t working. Eventually, I got it fixed! It turns out the problem is the resolution and fullscreen mode of Dos Box. I did see a few others recommend installing a standalone version of Dos Box, but that’s a bunch of extra work. I always try to find a better solution.

Long story short, if you want to play Dark Forces on your Steam Deck, here’s how to get it working.

  • Press the Steam button then navigate to Power > Switch to Desktop.
  • In Desktop mode, use a file manager (like Dolphin) and browse to the directory where you installed Dark Forces. Mine was in SD Card > steamapps > common > Dark Forces.
  • Open Dosbox.conf — it should open in a notepad-like app.
  • Change fullscreen=true to fullscreen=false.
  • Below that add windowresolution=1200×800.
  • Click File > Save in the top left of the window.

That’s it. Now, just go back to the Steam Gaming Mode and try starting Dark Forces like you would any other game. Your problem should be fixed! I assume this would work with most other games that use Dos Box, as well.