Note: This is taken from a README.txt included with the mod. The article may not be frequently updated. Always check the README.txt for the newest version of this text.

ELDEN RING Reforged Compatibility: Linux / Steam Deck

ELDEN RING Reforged is fully functional on Linux and Steam Deck!

The following instructions are written assuming you are using the Steam Deck.
Otherwise, you'll have to install Steam and Proton, and generally get Linux gaming underway as it is on the Deck.

You will not be able to use the comfortable launcher designed for Windows,
but hopefully the installation process is still somewhat simple.

INSTRUCTIONS

1) Place the mod NEXT TO your "Game" folder, inside your "ELDEN RING" folder.
The folder structure should look like this (assuming the default location for Steam):

- ~/.steam/steamapps/common/ELDEN RING/Game
- ~/.steam/steamapps/common/ELDEN RING/AdvGuide
- ~/.steam/steamapps/common/ELDEN RING/ERRvX.YY.ZZ
- ~/.steam/steamapps/common/ELDEN RING/ERRvX.YY.ZZ/mod
- ~/.steam/steamapps/common/ELDEN RING/ERRvX.YY.ZZ/README - ELDEN RING Reforged.txt

This is IMPORTANT! The compatibility files will expect this structure.
Do NOT put the mod files INSIDE the "Game" folder, but next to it.

Your location will likely differ if you installed ELDEN RING on your SD card, or Steam is located
in a different location. Simply locate your ELDEN RING install using Steam.

2) Add the following files as Non-Steam Game shortcuts to Steam (from inside the mod folder). As they are BAT and EXE files,
you need to select "All Files" in the file dialog when searching for them.

- extras/compatibility/linux/ELDEN RING Reforged.BAT
- extras/compatibility/linux/ELDEN RING Reforged (Seamless Coop).BAT (if planning to play Seamless)
- mod/menu/deploy/Gideon.exe

3) Under the Properties for each of the shortcuts in Steam, select "Proton Experimental" as compatibility option.

If that doesn't lead to good results, a version confirmed to work well is Proton GE 9.4.

4) For the "Gideon.exe" shortcut, add the following launch options:

--user --project "ELDENRINGReforged"

5) Run the "Gideon.exe" shortcut. This sets up the UI images, such as tutorial images and large inventory icons.
Wait for the program to finish.

6) If you wish to use alternate controller prompts, repeat steps 4) and 5), but replace
"ELDENRINGReforged" with any of the following:

- "PS4UIforModsbylosh11"
- "PS5UIforModsbylosh11"
- "SwitchUIforModsbyZeusOfTheCrows"
- "DefaultControllerPrompts(XboxOne)"

7) Consult the "SAVE FILES" section below for information on how to correctly copy your Vanilla saves over if desired.

8) Also check out all the other sections for assorted information.

9) Run the "ELDEN RING Reforged" shortcut from Steam.

10) Enjoy the game.

SAVE FILES

Steam on Linux stores save data and other things in its own "Proton context" for each game, located in:

~/.steam/steam/steamapps/compatdata

Creating a "Non-Steam Game" shortcut will also create its own context just for that shortcut. Due to this,
the ELDEN RING vanilla save files will be in a different location from your Reforged save files.

The App ID for ELDEN RING is "1245620", so that is the name of the "compatdata" folder where you'll find your
ELDEN RING vanilla save files. The ID for your Reforged non-Steam game shortcut will be randomly generated,
so you must find it on your own.

To use your vanilla save file with Reforged, copy the "ER0000.sl2" file that you will find in your ELDEN RING
compatdata folder, to the equivalent location in the Reforged compatdata folder, and rename it to "ER0000.err".
This should let the mod recognize the save data.

SEAMLESS COOP

If you want to use Seamless Coop, you need to follow the instructions in the "README - Seamless Coop" file,
then use the *other* shortcut you added in Step 2) above.

ADDING DLL MODS

If you want to add DLL mods like Posture Bar and Erd Tools, add them
to the "dll\active" folder in the Reforged folder.

Afterwards, edit either of the following files:

- extras\compatibility\linux\internals\modengine\config_reforged.toml
- extras\compatibility\linux\internals\modengine\config_seamless.toml

based on whether or not you're using the Seamless shortcut.

Add a new entry to the "external_dlls" list, and point it at the DLL you just added.
Be careful with the commas in the list.

After saving the file, launching the mod should now include the added DLL.

A number of tweaked DLLs which work with Reforged is available in "dll\optional". Copy them over to "dll\active"
and follow the above instructions if you wish to enable them.

KNOWN ISSUES

- The Steam Deck has a 16:10 resolution, which is not supported by ELDEN RING by default, leading to small issues with the UI.