Running ME Mod Manager on your Steam Deck is not hard - but it will require some setup.

Requirements:

• A Steam Deck in Desktop Mode
  
• Lutris (Install from the Discover Store)[lutris.net]
  
• Mass Effect Legendary Edition
  
• Proton

Also helpful is being able to dock your deck to a monitor/keyboard/mouse, but this is not strictly required.

Proton (and WINE, on which Proton is based) uses "prefixes" (a collection of configuration files) to tell it how to run Windows software on Linux. We'll be copying the Prefix Steam auto-generates for Mass Effect and making some small tweaks.

You should find your prefix in
13328670 is the Steam Game ID for Mass Effect Legendary Edition - if you are using this for a different game, the ID will be different.

This is what the folder contents should look like:

What you will want to do is copy that entire folder somewhere else - I copied it to but anywhere should work.

It is very important to make a copy! We will be making changes to these files/folders and if you don't make a copy, you will break your Legendary Edition Install

You'll want to download the Mod Manager[www.nexusmods.com] and extract it into the prefix you just created.

I put it into
However, anywhere in the drive_c folder should be fine.

In this stage, we'll be extracting the executable and setting up our Lutris profile.

If you're able to extract the executable some other way, simply update your references in this step to ME3TweaksModManager.exe - you still need to set up Lutris and so on as described here.

By default, Lutris uses WINE and not Proton. We'll want to start Lutris from the command line:

Open up the console and input
Here we'll be doing the setup for the application. Open up Lutris and click the plus sign in the top left.

From there, add a locally installed game:

You can name it whatever you want - the key thing here is to make sure you selece WINE.

These are more important - make sure you:

• Designate the executable we saved earlier
  
• Use the new prefix we created

Make sure you select Proton as the Runner. I also deactivated all the visual settings and set the resolution manually because I was running into issues with flickering/etc - YMMV. You also don't need the Anti-Cheat so you can disable those.

All other settings we left at the defaults. Hit save and you should see your game in Lutris.

Start the game you just created:

After a second, you should see the extraction dialogue pop up:
You'll want to browse to a new location for the executable - I used Program Files (where we have the current exe) but it can be anywhere.

When you're done, hit OK and let it extract. When you're done, a Windows Explorer window should show up:

You're done extracting! Close the window and proceed to the next step

This part is easy - we'll be using the same configuration for the Mod Manager itself.

Click on the game we created earlier and hit "Configure". We'll want to be changing the executable path to the new extracted exe.

For me, the new path is
It should be the same for you unless you saved things somewhere else.

This is the only change - hit save when you're done.

While not strictly required, it is helpful to create a desktop shortcut for your game so you don't have to boot up Lutris from the command line every time.

Right click on the game we created and hit "Create Desktop Shortcut". This should create a shortcut on your desktop.

We need to add a command line argument to use Proton instead of WINE. Right click on the shortcut you just created, open up the properties and go to application.


You'll need to add the same argument as before:
The full argument in the Arguments field should be something like:
Hit play on your game again. After a few seconds, you should see the manager pop up!

If it asks to update, don't let it - I haven't tested, but it will probably break.

You're basically done! Just some setup and you'll be ready to install some mods

All that remains now is to tell the mod manager where to find your game.

Your Legendary Edition Binaries should be in a hidden folder This is a problem - we can't browse to hidden folders from the mod manager!

We'll need to do a little hack: Open up the console and type in

This should create a link to the directory on your desktop.

Click "Add Target" in the mod manager and browse through the folder you just created - the path should be
You should probably back up your game. The process here is identical to windows.

You can save it anywhere you want - however, I would recommend you save it on the deck's SD card because the backup can be quite large. The SD card should show up as a lettered drive in the explorer window (For me it was E)

You can't drag and drop the mods - you'll need to manually add them. You can find that option in Mod Management > Import Mod > Import Mod from .7z/.rar/.zip/.exe/.me2mod

You can import mods from anywhere on your system - for example, I just save mine in Downloads, which can be found at
From there, the process is identical to windows -just follow the prompts.

And you're done! Manager is set up.

Happy modding!

When you're ready to play, launch the game normally from Steam (desktop mode or gaming mode, doesn't matter)

All of your changes will carry over.

You shouldn't launch the game from the manager - it might work, but I wouldn't count on it. Launch from Steam to avoid headaches.

Enjoy your newly modded game!