How to Play Warcraft III: Reforged and Forsaken Kingdom on Steam Machine (GE-Proton Guide)

Install Battle.net as a non-Steam game, then select GE-Proton11-7 for its Steam shortcut. That specific release includes the Warcraft III: Reforged authentication fix for the misleading VPN error introduced with Patch 3.0. The GE-Proton 11-7 release notes name the fix directly.

Forsaken Kingdom adds a prologue and three campaign chapters to Reforged. It requires the base game, a Battle.net account, and the Battle.net desktop app. Both use the launcher setup below.

This guide adapts documented SteamOS installation steps for Steam Machine. We have not benchmarked the game on Steam Machine. The confirmed login fix does not establish frame rates or trouble-free campaign play.

What you need

Use a keyboard and mouse for installation and the first game launch. They also suit Warcraft III's unit selection, camera movement, and hotkeys better than starting with a controller layout.

• A Steam Machine running SteamOS.
• A Battle.net account with Warcraft III: Reforged. Forsaken Kingdom is a separate purchase unless your bundle includes it.
• An internet connection. Blizzard's Patch 3.0 notes make the Reforged client online-only; the separate Classic client is outside this guide.
• Enough free space for the game's current installer estimate, plus Battle.net, the Proton prefix, and updates.

Keep the keyboard and mouse nearby when returning to Gaming Mode. Battle.net still has sign-in and launcher screens to navigate.

Why this guide uses GE-Proton 11-7

The original certificate compatibility report traces the VPN message to Warcraft III passing an 88-byte certificate configuration to Wine's crypt32.dll. Older implementations accepted smaller layouts and rejected that call. The report identifies GE-Proton 11-7 as carrying the fix.

For the steps below, install and select GE-Proton11-7 explicitly. It is a community Proton build, distinct from Valve's Proton and Proton Experimental. A newer version is not required to follow this guide, and there is no reason to replace a working setup just to chase a release number.

The error can be a compatibility failure without anything being wrong with your VPN. It does not mean every connection error has the same cause.

1. Install GE-Proton 11-7

ProtonUp-Qt installs compatibility tools for Steam. If you already use ProtonPlus, install the same GE-Proton version there instead; our Proton guide covers that manager.

1. In SteamOS, open the Steam menu, choose Power, then Switch to Desktop.
2. Open Discover, search for ProtonUp-Qt, and install it.
3. Launch ProtonUp-Qt and select Steam as the installation target.
4. Choose Add version, select GE-Proton, then GE-Proton11-7.
5. Install it, then fully exit and reopen Steam so the tool appears in Compatibility.

Installing a build does not select it for your launcher. You will do that after adding the installer to Steam.

2. Install Battle.net through Steam

Download the Windows installer from Battle.net's official download page. This setup runs the Windows launcher through Proton.

1. In desktop Steam, choose Games → Add a Non-Steam Game to My Library.
2. Select Browse and open the downloaded Battle.net-Setup.exe. Choose All Files if the dialog hides it, then Add Selected Programs.
3. Right-click the new library entry and open Properties → Compatibility.
4. Enable Force the use of a specific Steam Play compatibility tool and select GE-Proton11-7.
5. Launch the installer from Steam and accept its default installation folder.
6. When installation finishes, quit Battle.net, including its system-tray instance, before editing the shortcut.

Steam has now created a Proton prefix: a folder containing a Windows-style drive and the installed launcher. GamingOnLinux's manual installation walkthrough documents this Steam-and-Proton method. Its older Proton example is not the version recommendation for Warcraft III here.

3. Point the same shortcut at the launcher

Keep the Steam entry you used for installation. Change its target rather than adding the installed launcher as a second non-Steam game.

Open Dolphin, press Ctrl+H to show hidden folders, and look in:

~/.local/share/Steam/steamapps/compatdata/

The ~ means your home folder. If Steam's directory is linked through ~/.steam/steam/, follow it to steamapps/compatdata instead.

Sort the numbered folders by modification time to narrow the search, then confirm the candidate contains:

pfx/drive_c/Program Files (x86)/Battle.net/Battle.net Launcher.exe

The timestamp alone is not proof: other games can update their prefixes too. In Dolphin, use Copy Location on the launcher to get its full absolute path.

Return to the existing Steam shortcut's Properties → Shortcut. Rename it Battle.net and replace Target with that copied path, enclosed in double quotes. Set Start In to the containing Battle.net folder, also quoted.

These examples show the shape only. Replace <user> and <ID> with the actual values copied from your Steam Machine:

Target

"/home/<user>/.local/share/Steam/steamapps/compatdata/<ID>/pfx/drive_c/Program Files (x86)/Battle.net/Battle.net Launcher.exe"

Start In

"/home/<user>/.local/share/Steam/steamapps/compatdata/<ID>/pfx/drive_c/Program Files (x86)/Battle.net/"

Check Compatibility again: it should still force GE-Proton11-7. Launch Battle.net from this entry and confirm it opens before deleting the downloaded installer.

Removing the shortcut and creating another can give you a different prefix. If you already did that, locate the original installation before reinstalling or deleting anything. An empty new prefix does not prove the original files are gone.

4. Install Reforged and Forsaken Kingdom

Sign in to Battle.net, choose Warcraft III: Reforged, and install it. Let the game and launcher finish updating before pressing Play.

Forsaken Kingdom is attached to your Battle.net game entitlement. If the campaign remains locked, confirm that the signed-in account owns it; installing GE-Proton does not unlock purchased content.

Once the game reaches its menu, return to Gaming Mode using the desktop shortcut and launch Battle.net from Steam's non-Steam library. Confirm that both the launcher and the game receive keyboard and mouse input there.

5. Set graphics for your display

Blizzard's Patch 3.0 notes distinguish three visual modes. These are different presentations, not a Low, Medium, and High preset ladder.

Check the options offered for the campaign or map you are launching. Do not assume that every campaign supports every mode just because all three appear elsewhere in the client.

For an initial Steam Machine setup, try 1920 × 1080 and a 60 FPS limit before increasing resolution. Those are troubleshooting starting points, not measured performance results. Test an actual mission with units and effects on screen before deciding the setup is stable.

If performance falls short, lower resolution and test the added Supersampling, Point Light Shadows, and Water options individually. The same official patch thread records Ambient Occlusion returning in 3.0.1 and warns that enabling it can reduce performance.

On a TV, check text, tooltips, the minimap, and cursor visibility from your seat. A higher output resolution is not useful if you cannot read the interface. Our Steam Machine TV setup guide covers the display side.

6. Choose keyboard and mouse or Steam Input

Start with keyboard and mouse. Check the game's hotkey settings before copying bindings, especially if you use a custom layout.

For a Steam Controller or another controller, Steam Input's legacy mode can map buttons to keyboard and mouse actions. Open controller settings for the Battle.net shortcut, then build around these jobs:

• Cursor movement and separate left- and right-click actions.
• Camera movement and a way to reach control groups.
• Modifier keys for assigning groups and queuing orders.

A trackpad can handle the cursor, while a radial menu can hold number keys without consuming every physical button. Test click-and-drag selection and modifier combinations in a quiet mission before relying on the layout. These are suggested bindings, not a tested Warcraft III controller profile.

Troubleshooting

The game says to check your VPN. Open the Battle.net shortcut's Compatibility settings and confirm GE-Proton11-7 is selected. Fully quit the game and launcher before relaunching; reboot Steam Machine if you are unsure whether they are still running. The documented certificate failure is one explanation for that message, not a diagnosis of every network problem.

Battle.net stops opening after you edit the shortcut. Check that Target names the installed Battle.net Launcher.exe, Start In names its containing folder, and both paths are quoted. Verify the prefix number against the actual file. Neither field should still point to the installer in Downloads.

The campaign is locked or login stalls. Check the signed-in account, expansion ownership, connection, and pending launcher or game updates before changing Proton again. Avoid deleting the prefix as an early troubleshooting step: it can contain the launcher, game, configuration, and local saves.

An older save will not load after a game update. Blizzard's October 7 3.0.1 patch notes warn that previous save files are no longer valid, while progress between chapters and acts is retained. That documented save-format break is separate from the Proton login fix.