Playing on Linux and Steam Deck

Kingdom Come: Deliverance II has no Linux version, but it runs very well on Linux through Proton, the compatibility layer built into Steam. KCD:MP runs the same way: the KCD:MP launcher runs under Proton like any Windows program and starts the game from there. Players use it this way today. It is not part of our own testing yet, so if something on this page does not match what you see, tell us on Discord (the last section says what to send).

You need the Steam version of the game. The steps below take about ten minutes the first time.

What you need

• Steam for Linux, with the game installed and Steam Play (Proton) turned on for it.
• Proton-GE, a community build of Proton - the launcher’s window is known to work with it. The easiest way to get it is ProtonUp-Qt (on Flathub, or the Discover store on a Steam Deck): pick Proton-GE and install the latest version. Steam’s own Proton and Proton Experimental may work too, but the launcher’s window has not been seen working with them.
• Protontricks (on Flathub as Protontricks, or from your distribution). If you use the Flatpak, also Flatseal to give it access to your games (step 5).
• KCD:MP itself, from kcd-mp.com/download.

On a Steam Deck, do steps 1 to 6 in Desktop Mode. Once it works, you can start KCD:MP from your library in Game Mode.

1. Start the game once

Start Kingdom Come: Deliverance II from Steam as you normally would, wait for its main menu, and quit. This checks that the game itself runs on your system before KCD:MP is added.

2. Unzip KCD:MP

Unzip the KCD:MP download into a folder of its own, for example ~/Games/KCD-MP. Do not put it into the game’s Mods folder.

3. Add the launcher to Steam

In Steam, choose Add a Game → Add a Non-Steam Game… (bottom left of the library), click Browse, pick KcdMp_launcher.exe from the folder of step 2 and add it.

Then right-click the new entry → Properties → Compatibility, tick Force the use of a specific Steam Play compatibility tool and choose the Proton-GE version you installed.

4. Start it once

Start the new entry from Steam. The first start sets up a Proton folder of its own for the launcher, which takes a moment, and then shows a message that the window needs the WebView2 runtime. Close the message - that is expected, and the next step installs it.

5. Install WebView2 with Protontricks

If you use the Flatpak version of Protontricks, open Flatseal first, pick Protontricks and, under Filesystem, give it access to the drive or folder that holds your Steam library (your home folder is usually enough; an SD card or a second drive needs its own entry).

Then open Protontricks:

1. Pick the launcher’s entry - it shows as a non-Steam shortcut named KcdMp_launcher.exe.
2. Choose Select the default wineprefix.
3. Choose Install a Windows DLL or component.
4. Tick webview2 in the list and press OK.

Follow the installer to the end. Some errors may show on the way; they can usually be ignored.

6. Start the launcher and join

Start the launcher’s entry from Steam again: the KCD:MP window opens with the server list.

The launcher looks for the game in your Steam libraries. If it says it cannot find the game, open Settings → Game folder and enter the game’s folder with Z: in front of the Linux path - for the default Steam library:

Z:\home\<your user name>\.local\share\Steam\steamapps\common\KingdomComeDeliverance2

On a Steam Deck the user name is deck; a game on an SD card is under Z:\run\media\.... In Steam, right-click the game → Manage → Browse local files shows you the folder.

Pick a server and press Join. Keep Steam running while you play - the game checks your copy through Steam.

Good to know

• The game runs inside the launcher’s Proton folder, not the game’s usual one, so your graphics options and key bindings start from the defaults the first time, and the first minutes may stutter while the game prepares its shaders.
• Steam shows the launcher’s entry, not the game, as what you are playing.
• On a Steam Deck the chat needs a keyboard: press Steam + X for the on-screen one.
• Voice chat and the servers’ own web pages have not been checked on Linux yet. If they work - or don’t - for you, tell us.

If something goes wrong

Ask for help on our Discord and send these, so we can see what happened:

• Which steps worked, and what you saw at the one that did not.
• Your system: PC or Steam Deck, your distribution, your graphics card and driver version, the Proton version, and whether Steam is the Flatpak.
• client.log - KCD:MP’s own log, in the launcher’s Proton folder: ~/.local/share/Steam/steamapps/compatdata/<number>/pfx/drive_c/users/steamuser/AppData/Local/KcdMp/client.log. <number> is the launcher’s shortcut; protontricks -l (or flatpak run com.github.Matoking.protontricks -l) lists it next to KcdMp_launcher.exe. Any crash-....txt in the same folder too.
• kcd.log - the game’s own log, in the game’s folder.
• Proton’s log, if the game does not start at all: in the launcher entry’s Properties → General → Launch Options, enter PROTON_LOG=1 %command%, start it again, and send steam-<number>.log from your home folder. Clear the line afterwards.

Send only these files: the others in that KcdMp folder hold your player key and the passwords of servers you joined.