Proton

Proton is Valve's compatibility layer for running many Windows games through Steam on Linux.

How Proton works

Proton combines technologies including Wine and DXVK with additional compatibility work from Valve and the Linux gaming community.

Steam downloads and manages Proton versions automatically.

Enable compatibility for Windows games

Open Steam settings and find the compatibility or Steam Play section.

Steam can use Proton automatically for supported titles. You can also enable compatibility for additional Windows games when required.

Choose a Proton version for a game

To select a specific Proton version for one game:

1. Open your Steam library.
2. Right-click the game.
3. Open Properties.
4. Open the Compatibility section.
5. Enable the option to force a specific Steam Play compatibility tool.
6. Select the Proton version you want to test.

Proton Experimental

Proton Experimental contains newer compatibility fixes than the regular stable Proton releases.

It can be useful for recently released games or titles that require newer fixes.

If a game works correctly with the default Proton version, there is usually no reason to force Proton Experimental.

Native Linux games

Some Steam games provide a native Linux build.

Steam may use the native version by default instead of Proton. Forcing Proton is optional and may sometimes help if the Windows build works better than the native version.

Changing Proton versions

Different games may behave differently with different Proton releases.

If a game stops working after changing versions, return to its Compatibility settings and try the previous version or the default selected by Steam.

Game compatibility

Not every Windows game works perfectly under Proton.

Compatibility can depend on:

• the game engine
• graphics APIs
• anti-cheat support
• launchers and account systems
• the selected Proton version
• graphics drivers

Anti-cheat

Some multiplayer games use anti-cheat systems that may not support Linux or Proton.

In those cases the game may fail to start or multiplayer functionality may be unavailable even when the rest of the game would otherwise run.

Basic troubleshooting

If a game does not start, first try:

1. Restart Steam.
2. Check for Octlitch system updates.
3. Update Steam and Flatpak applications.
4. Verify the game's files in Steam.
5. Try another Proton version.
6. Check that your graphics driver is working correctly.

Update the system:

sudo dnf upgrade --refresh

Update Flatpak applications:

flatpak update

Proton logs

Advanced troubleshooting can use Proton's logging facility.

Add the following to the game's Steam launch options:

PROTON_LOG=1 %command%

Launch the game once. Proton will generate a log file in your home directory using the game's Steam application ID.

Remove the launch option when you no longer need diagnostic logging.

Custom compatibility tools

Third-party Proton builds exist, but they are not part of the standard Octlitch installation.

Start with the Proton versions supplied by Steam before adding custom compatibility tools.