Clair Obscur: Expedition 33 is a visually ambitious Unreal Engine 5 title that challenges even high-end hardware. Unfortunately, it doesn’t run well out of the box on the Steam Deck. Players often experience frame rate drops, sluggish combat responsiveness, and poor exploration performance.
Clair Obscur: Expedition 33 Steam Deck Mod Guide – Play at 50+ FPS
This guide provides a custom optimization mod built specifically for the Steam Deck. With this mod, you can expect smoother gameplay at up to 55 frames per second – without sacrificing much in terms of visual quality.
If you’re looking to transform your performance from inconsistent and laggy to smooth and immersive, you’re in the right place.
Why Optimize Expedition 33 for Steam Deck?
At launch, Expedition 33 runs from acceptable to poor on Steam Deck, with performance dips as low as 18 to 24 frames per second. This makes some gameplay sections frustrating, especially when precise movement or timing is required.
This Steam Deck optimization mod is designed to:
- Stabilize combat performance around 45 frames per second
- Maintain 48 to 55 frames per second in exploration zones
- Improve overworld performance from roughly 20 to a stable 30 frames per second
- Maintain high visual quality while improving responsiveness
- Tailor performance to the Deck’s hardware and SteamOS using Vulkan and DirectX 12 via Proton
What the Mod Changes
Unlike mods that simply turn off visual features, this one fine-tunes Unreal Engine 5’s internal systems. It improves performance while preserving as much of the graphical experience as possible.
Here’s what the mod does:
- Tweaks numerous graphical settings rather than disabling them
- Optimizes shader handling, garbage collection, threading, and more
- Customizes configuration specifically for Steam Deck hardware and software stack
- Provides a balance between visual fidelity and smooth performance
The result is an optimized game that looks great and runs far better than default settings allow.
How to Install the Mod on Steam Deck
You’ll need to download the latest version of the Steam Deck optimization mod from Nexus Mods.
Download Link:
Search for “Clair Obscur Steam Deck Optimization V5” on NexusMods or go directly to:
www.nexusmods.com/clairobscurexpedition33/mods/25
Step 1: Extract the Mod Files
After downloading, unzip the file. Inside, you’ll find:
- GameUserSettings.ini
- Engine.ini
Step 2: Locate the Configuration Folder
On your Steam Deck, navigate to the following folder:
home/deck/.local/share/Steam/steamapps/compatdata/1903340/pfx/drive_c/users/steamuser/AppData/Local/Sandfall/Saved/Config/Windows/
You can paste this path into the file manager or navigate manually from your home directory.
Step 3: Replace the Existing Files
In the Windows folder:
- Delete the existing GameUserSettings.ini file
- Copy both new files (GameUserSettings.ini and Engine.ini) into the folder
Step 4: Make the Files Read-Only
There are several ways to do this. Choose whichever method you’re most comfortable with.
Method 1: File Manager
- Right-click the “Windows” folder or each file
- Go to Properties, then Permissions
- Set them to “Can only view”
Method 2: Terminal (Recommended)
Open a terminal window in the “Windows” folder and enter the following:
chmod 444 Engine.ini
chmod 444 GameUserSettings.ini
This ensures the game does not overwrite the optimized settings.
Step 5: Add Launch Options in Steam
Open Steam on your Deck, then:
- Right-click the game (or select the gear icon)
- Go to Properties, then the General tab
- Under Launch Options, enter the following:
SteamDeck=0 RADV_PERFTEST=aco,gpl %command%
These parameters improve Vulkan performance using the ACO and GPL drivers.
Optional Enhancement: Install Latest XeSS for More FPS
Installing the latest version of Intel’s XeSS (Xe Super Sampling) can significantly boost performance without a major visual downgrade.
How to Update XeSS
- Visit Intel’s official XeSS GitHub page and download the latest release
- Open the downloaded ZIP file and go into the “bin” folder
- On your Steam Deck, open this directory:
home/deck/Desktop/common/Expedition 33/Engine/Plugins/Marketplace/XeSS/Binaries/ThirdParty/Win64/
- Replace the existing four XeSS files with the updated ones from the ZIP. Be sure to back up the original files just in case
Recommended Settings for Best Visuals and Performance
These settings provide a solid visual experience while maximizing smoothness on the Steam Deck:
- XeSS: Use “Performance” or “Ultra Performance” modes
- Shadows: Medium (Low for extra performance)
- Anti-Aliasing: Off (uses too many resources)
- Effects and Post-Processing: Low (already optimized in the mod)
- Textures: Low or Medium, depending on preference
If the game appears too dark
You can adjust brightness and gamma in the in-game menu. For deeper customization:
Open the Engine.ini file and find this line:
r.TonemapperGamma=1
Reduce the value to 0.9 or 0.8 for a brighter image
How to Uninstall the Mod
To revert to the default game settings:
- Navigate back to the same folder
- Delete both Engine.ini and GameUserSettings.ini
- The game will recreate its default configuration on launch
Note: This mod is not compatible with other performance or graphics optimization mods. Use it on its own for the best results.
Frequently Asked Questions
Is this safe to use on Steam Deck?
Yes. The mod only replaces configuration files and does not alter core game files.
Does it work on Windows too?
It’s specifically tuned for SteamOS with Proton using Vulkan and DX12. Windows users may see different results.
Will it break updates or cause crashes?
No. These are config file tweaks that can easily be removed if necessary.
Can I still change settings in-game?
It’s recommended not to change in-game settings after applying the mod, as this may overwrite the configuration.
Final Thoughts
Clair Obscur: Expedition 33 is an ambitious title, but like many Unreal Engine 5 games, it struggles on portable hardware like the Steam Deck. With the optimization mod detailed in this guide, you can dramatically improve your experience—achieving up to 55 frames per second while preserving visual quality.
Whether you’re deep into its artistic world or just starting out, this is the best way to enjoy the game as it was meant to be played – on the go, smoothly and responsively.
If you found this guide helpful, consider sharing it with other Steam Deck owners or linking to it in discussions.
Last Updated on May 20, 2025
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