Frequently Asked Questions

How to use Mod Installer on Steam Deck?

In this tutorial we learn how to install mods for Far Cry games on Steam Deck using Mod Installer.

Since Steam Deck is using SteamOS which is based on Linux, we can't simply run Mod Installer same way like on Windows.


It's recommended to use mouse and optionally keyboard for the tutorial and later for using Mod Installer.


Before you start, there are two ways:

  • First - Uplay and the game are installed in default folders (you'll not be able to manually select game folder, only way is write game path in Mod Installer config file or leave Mod Installer automatically search for game folder (more later))
  • Second - to have installed Uplay and the game in custom locations, for example Documents (you can manually select game folder in Mod Installer)

This tutorial describes the second way. On the end there is small pointer how to use Mod Installer in the first way.


Also note, do not run Mod Installer from Gaming Mode, you can experience flashing screen and poor FPS. Always switch to desktop mode to install mods.


So, let's begin.


1) Switch to desktop mode

Turn on your Steam Deck and go to desktop mode.


2) Download

Go to FCModding website and download Mod Installer and a modpack, in this tutorial I selected FC6, so there will be Libertad mod, but it's same for all other main modpacks.


3) Unzip using Ark

Unzip both zips using Ark tool.


After you unzip it, move _FC6_Libertad.bin to the unzipped Mod Installer folder.


Now since we're in Linux, we can't just run exe files there. Rather we will launch Mod Installer through Steam via GE Proton.

So now we are going to install GE Proton. If you're already have installed it, you skip it.


4) Installing GE Proton

Open Discover and type "protonup" and search it.

Install the tool.


After installing, open the tool. Click on "Add version" and in the new dialog select "GE Proton" and "GE-Proton7-55" and click "Install".

After installing, close the tool.

Now we can add Mod Installer to Steam.


5) Adding Mod Installer to Steam

Open Steam and select "ADD A GAME" and "Add a Non-Steam Game...". Now find Mod Installer exe file - FCModInstaller.exe.


Now we need to make some edits so the Mod Installer will be able to run. Click on gear icon and click "Properties".

In the new window click on "Compatibility" and there check the check box and from the list under it select "GE-Proton7-55".


Now return back to "Shortcut" and into the "LAUNCH OPTIONS" box type this:

PROTON_USE_WINED3D=1 %command%


6) Running Mod Installer

Now close the window and click on the green button "PLAY". If it was successfull, Mod Installer will open. Now you can select from the window for what FC game you want to run the Mod Installer.


Note: if after selecting the game Mod Installer become black, move the mouse over the window, it become visible again.


Now because every app from Windows runs in own "sandbox", Mod Installer can't see where are games installed (and then it can automatically find the game folder), so we must manually find the game folder.

So click on the "<" and "P" buttons.


In the dialog go to (it depends where exactly you have the game installed): Z:\home\deck\Documents\Far Cry 6\bin\

And here is the warning about install location - by default, the game is installed in hidden folder and you're not able to go to the folder in this dialog, so that's why you must install (or later move) the game to some better location, for example Documents.


After you select the game exe, you can use Mod Installer to install any packages, just like on the PC.

Also note, do not run Mod Installer from Gaming Mode, you can experience flashing screen and poor FPS. Always switch to desktop mode to install mods.


7) Optional / advanced - auto search for the game in Mod Installer

If you have installed the game in default location, you can force Proton to use Uplay sandbox for running also Mod Installer.

We just need to find which folder it is.

  • Open Steam and run Uplay.
  • Once it's running, close it.

Now we must go to specific location, so open Dolphin and go to: /home/deck/.local/share/Steam/steamapps/compatdata/

And now here it's a bit hard, you must go through every folder and inside of each of them you must look to Modified date of a file "pfx.lock" - it must say "Just now" or like "X minutes ago" - this is sign of that Uplay is using this folder.

Once you find it, copy the number name of the folder, so for example 2452370234 (your can be different).


Now open Steam and open "Properties" of Mod Installer again and edit the "LAUNCH OPTIONS" to this:

PROTON_USE_WINED3D=1 STEAM_COMPAT_DATA_PATH="/home/deck/.local/share/Steam/steamapps/compatdata/<your ID>" %command%

The <your ID> is your folder name, so for example:

PROTON_USE_WINED3D=1 STEAM_COMPAT_DATA_PATH="/home/deck/.local/share/Steam/steamapps/compatdata/2452370234" %command%


That's all. If you found right folder, then Mod Installer now can automatically select the game folder.


8) Optional / advanced - manually write the game path

If you know the game path, you can manually set it in Mod Installer config.

Run Mod Installer at least once, so a file SettingsFC.xml will be created. It's in the same folder as Mod Installer exe file.

Now open the file with Kate.


Find line with "PatchLocation" and edit it with your game path and at end add "data_final\pc\patch.fat". Just like you see on the picture.

Save the file and run Mod Installer, now the game should be selected.



That's all.

If you will have problems, ask in the FCModding Discord server.