Proton (Steam Play)

A Windows game on Linux sounds like a pizza in a toaster. With Proton it usually just works, as long as no anti-cheat blocks the door.

The short answer

Proton is Valve's compatibility tool for Steam Play that lets games made only for Windows run on Linux, and it is built on Wine [1]. Valve describes it as a modified Wine plus a collection of high-performance graphics API implementations and says that most games work out of the box [2]. Proton comes with the Steam client, and Valve says most users should use that version [1]. Our assessment: Proton is the normal way to play a Windows Steam library on Linux; check anti-cheat and DRM before you rely on it for a specific game.

How it works

1. Wine underneath. Wine provides Windows interfaces on Linux, so a Windows program can run without Windows. Proton bundles its own Wine with additional components and is selected per game inside Steam [1].
2. DirectX becomes Vulkan. DXVK implements Direct3D 8, 9, 10 and 11 on top of Vulkan [4]. vkd3d-proton implements Direct3D 12 on Vulkan and is the development effort for Direct3D 12 in Proton [5]. It needs a driver with Vulkan 1.3 [5], so the graphics driver matters as much as the GPU.
3. Several versions side by side. Steam ships several Proton versions; a game uses Valve's default or the one you pick in the settings [1]. On 15 Oct 2026, Valve's changelog listed Proton Experimental as containing all changes from Proton 11.0-2 plus further fixes [3].
4. Which games use it. Under Settings, Steam Play, "Enable Steam Play for supported titles" covers games Valve has checked, and "Enable Steam Play for all other titles" covers every other non-native game [6]. In Valve's Steam for Linux issue tracker, the Valve account kisak-valve explained the order: a per-game choice beats native Linux versions and Valve's list, which beat the global setting [7].
5. The limits. Proton supports Easy Anti-Cheat and BattlEye, but each developer has to enable this for their game. Kernel-space anti-cheat is not supported [2]. Valve also lists .NET or WPF launchers, Media Foundation and anti-tamper or DRM as known problem areas [2].
6. Hands off in multiplayer. If you install DXVK yourself outside Steam, the DXVK project warns that changing Direct3D libraries in multiplayer games may count as cheating and can get an account banned [4].

A practical example

A Windows game from your library refuses to start on Linux. In the library, right-click the game, open Properties, Compatibility, tick "Force the use of a specific Steam Play compatibility tool" and choose another Proton version, for example Proton Experimental [6]. If that does not help, switch back to the default by unticking the box. Advanced users can place their own Proton builds under ~/.steam/root/compatibilitytools.d/ and restart Steam [1]. Before you test a game, check whether it has a native Linux version; Canonical's Steam documentation notes that a native game likely works best without Proton [6]. This is a generic walk-through, not a test on our own hardware.

Checklist

• Check first whether the game is native; then you do not need Proton [6].
• Turn on "Enable Steam Play for all other titles" only if you also want untested games [6].
• Try Proton Experimental or an older version for a single game before giving up [1][3].
• Keep the graphics driver current; D3D12 games through vkd3d-proton need Vulkan 1.3 [5].
• Check the anti-cheat status of a multiplayer game before you buy it [2].
• Report a broken game on Valve's GitHub tracker or the Steamworks forum, as Valve asks [2].