What Is Proton on Steam Deck? (And How to Use It)
Proton is the reason you can play thousands of Windows games on Steam Deck without doing anything special. It’s a compatibility layer built by Valve that translates Windows API calls into Linux equivalents — so when you press Play on a Windows game, Proton handles the translation silently in the background.
You don’t need to understand how it works to use it. But knowing the basics helps when a game doesn’t launch or runs poorly.
How Proton Works
Steam Deck runs SteamOS, a Linux-based operating system. Most games on Steam are built for Windows. Proton sits between the game and the OS — it’s based on Wine (a long-running open-source project) but with significant additions from Valve including DXVK (translates DirectX 11/12 to Vulkan), VKD3D-Proton (DirectX 12 to Vulkan), and Steam Linux Runtime (a containerised environment for consistency).
The practical result: over 15,000 Steam games are Deck-compatible, and most run without any configuration.
Proton Versions Explained
Multiple Proton versions are available on Steam Deck, each with different compatibility profiles:
- Proton Stable (current version, e.g. 9.0): The default. Best for most games. Valve tests games against this version before marking them Deck Verified.
- Proton Experimental: The bleeding-edge version. Gets fixes faster than Stable. Use this if a game is broken on the current Stable version.
- Proton GE (Community build): A community-maintained fork with additional codecs and patches. Better for games with cutscene videos that show a black screen on standard Proton. Install via ProtonUp-Qt.
How to Change Proton Version for a Game
Step 1 — In your Steam library, right-click the game and select Properties.
Step 2 — Click the Compatibility tab.
Step 3 — Check “Force the use of a specific Steam Play compatibility tool” and select a Proton version from the dropdown.
Step 4 — Close Properties and relaunch the game.
This is the first thing to try when a game crashes or won’t launch. Switch to Proton Experimental, relaunch — if it works, leave it. If not, try Proton GE.
Steam Deck Compatibility Ratings
Valve rates every Steam game for Deck compatibility:
- Verified (green checkmark): Tested by Valve, works perfectly out of the box — text is readable, controls are mapped, runs at good performance.
- Playable (yellow): Works, but may need manual tweaks — small text, partial controller support, or requires you to configure something first.
- Unsupported (grey X): Doesn’t work currently. Can still try — ratings aren’t always current, and community patches may exist.
- Unknown: Not tested by Valve yet. Check ProtonDB.com for community reports.
ProtonDB — Your Best Resource
ProtonDB.com is a community-maintained database of Proton compatibility reports. Before buying a game or troubleshooting an issue, search the game on ProtonDB. You’ll find:
- Whether it runs well on Deck
- Which Proton version works best
- Any launch options or workarounds needed
- Performance expectations
ProtonDB grades: Platinum (works perfectly), Gold (minor tweaks needed), Silver (some issues), Bronze (runs but with significant problems), Broken (doesn’t run).
Non-Steam Games and Proton
Proton works with non-Steam games too. Add a game as a Non-Steam Game in your library, then right-click it, go to Properties → Compatibility, and enable Proton. This is how you run Epic Games Store titles, GOG games, or emulators that need Windows binaries.
For a step-by-step guide to running emulators on Steam Deck, see our Best Emulators for Steam Deck guide. For a full list of recommended games, see Best Games for Steam Deck.