???? The Final Fix: How to Play SCUM Multiplayer on Linux (Self-Hosted Server)

For many Linux users, the survival game SCUM is the last remaining title holding them to a Windows install due to anti-cheat issues. After extensive troubleshooting, we developed a robust, multi-step command-line fix that allows you to bypass the client-side issues and connect to a self-hosted server running without BattlEye.

This guide is specifically for users who host their own SCUM server with BattlEye disabled.

⚠ Important Warning

This process requires manually modifying your Steam/Proton environment and bypassing anti-cheat checks. This guide is only for use on a self-hosted server where you have explicitly disabled BattlEye. Use it responsibly.

Step 1: Fix Core Dependencies (The Winetricks Fix)

The game crashes during launch because it requires specific Microsoft runtimes that are not initially present in the Proton prefix. We use winetricks to install them.

1. Check/Fix Permissions (If needed)

If you encounter "Permission denied" errors during the winetricks steps, use this command (CRITICAL: Replace username with your actual Linux username):

sudo chown -R username:username /home/username/.steam/steam

2. Install Required Runtimes

Run the following two commands back-to-back. You will see pop-up Windows installer boxes; click "Install" or "Next" until they complete.

# Fixes the .NET Framework dependency (the main profile load issue)
WINEPREFIX="/home/username/.steam/steam/steamapps/compat/513710/pfx" winetricks dotnet48

# Installs the latest Visual C++ runtimes for stability
WINEPREFIX="/home/username/.steam/steam/steamapps/compat/513710/pfx" winetricks vcrun2019 vcrun2022

Step 2: The Final Launch Script (The Bash Power)

We must define all environment variables that the Steam client normally handles and then run the game with the final, stable flags.

1. Create a New Shell Script

Open your terminal and create a new file named scum_launch.sh (or similar) in your home directory:

nano ~/scum_launch.sh

2. Paste the Complete Command Block

Paste the script below. CRITICAL: Replace every instance of /home/username/ with your actual Linux home directory path. Also, verify that your Proton folder is named exactly Proton Hotfix (change this if you use Proton 9.0, etc.).

#!/bin/bash

# --- SCUM Multiplayer Launch Script for Linux ---
# NOTE: The Steam client must be running and logged in for authentication.

# 1. Define all necessary environment variables for Proton/Wine
STEAM_COMPAT_DATA_PATH="/home/username/.steam/steam/steamapps/compat/513710" 
WINEPREFIX="/home/username/.steam/steam/steamapps/compat/513710/pfx"
STEAM_COMPAT_CLIENT_INSTALL_PATH="/home/username/.steam/debian-installation" 
SteamAppId="513710"

# 2. Execute the game using the correct Proton version and flags
/home/username/.steam/steam/steamapps/common/Proton\ Hotfix/proton run \
    "/home/username/.steam/steam/steamapps/common/SCUM/SCUM/Binaries/Win64/SCUM.exe" \
    -nobattleye -dx11

# Final Flags:
# -nobattleye: Bypasses client-side anti-cheat checks.
# -dx11: Forces the stable DirectX 11 API, resolving the final graphics crash on Linux.
        

3. Finalize the Script

Save and exit the text editor, then make the script executable:

chmod +x ~/scum_launch.sh

Step 3: Launch and Connect

1. Start Steam: Ensure the Steam client is running and logged in.
2. Launch SCUM: Run your new script from the terminal:

   ~/scum_launch.sh

3. Connect:
   • The game should load the main menu, and the Multiplayer button should be clickable.
   • Use Direct Connect and enter your server IP and the **Steam Query Port** (which is usually the server's **Game Port + 2**).

Congratulations! You should now be able to connect and play SCUM multiplayer without needing a single byte of Windows.