shinratdr , 1 month ago

You can, but it requires going through the desktop interface to install them, if they use another launcher you have to set up that, frequently some trial and error, and then adding them into the Steam interface so they can launch easily with proper input support.

Do all that and set them up correctly, and they’ll run, but without one of the primary Steam Deck benefits which is that Valve does pre-compilation of shaders. That only works for native Steam titles, and it can be the difference between a game being playable and a stuttery mess, especially for more graphically intense titles.

For some games, there are also hardcoded patches in Proton that look for the SteamID of the game to apply them. Those also won’t have those fixes applied when adding them as non-Steam games.