Summary of how to get Morrowind running on the Deck with MGE XE and MWSE-Lua. MO2 is used to manage mods. Includes a method for keeping a desktop (Linux or Windows) in sync with the Steam Deck - useful since you can more easily manage your mods on the desktop with MO2, mlox, TES3Merge, Wrye Mash and then sync all of it over to the Deck.
In Steam's game mode
- Install Morrowind on your primary SSD (not your SD card)
- Right click the game in the Library, Properties > Compatibility > tick Specific Proton Version and select 9.0 or Experimental (which is at least 10.0)
- Run the game once - this will create a "prefix", essentially a small Windows install that Morrowind will run in