This guide explains how to add a Windows-only game (or application) to Steam Deck. It also works for Steam running on Linux on any hardware (your laptop, your desktop, etc.). By following these instructions you can add any freeware and fan-game to your system. Of course, just be careful and don't download anything suspicious.
This guide was originally written as a comment to a YouTube video. However, YouTube comments are trash and are randomly silently dropped, so I'm rewriting it here. It's also easier to point people towards this guide.
- You know how to use the desktop mode.
- You understand the concept of files and folders; and you know how to uncompress a ZIP file (or whatever format you have downloaded).