Launching the Modded Client

After install, the Launcher starts the modded game from GameRoot/games/<version>/ using the active loadout’s mod set. Vanilla SCP:SL remains managed by Steam and should be launched through Steam when you want to play non-Anomaly servers.

Launch a Loadout

Select a loadout and launch it. The Launcher:

1. Rebuilds GameRoot/loadouts/<name>/runtime/ from cached catalog packages and local/ overrides.
2. Links that runtime’s Mods/, UserLibs/, and UserData/ into the selected games/<version>/ folder.
3. Starts SCPSL.exe from that game-version folder.
4. Cleans up the loadout links after the game exits.

Use this when you want to connect to Anomaly-enabled servers or test Anomaly mods.

Windows junctions

On Windows, the loadout folders are activated with directory junctions, not administrator-only symlinks. If the game crashes or is force-closed, the next launch uses .anomaly_links.json to clean up stale links.

Launch arguments

The Launcher has an optional launch-arguments field. Anything entered there is passed to the modded game process.

Common examples include Unity or SCP:SL flags such as -popupwindow or custom resolution options. You do not need Anomaly-specific launch arguments for normal play.

The field is saved and reused on later launches.

Running on Linux

SCP:SL is a Windows game, so Linux launch behavior depends on how you run the Launcher:

• Steam Deck Gaming Mode or Windows Launcher under Proton: add Anomaly.Launcher.exe as a non-Steam game and force a Proton compatibility tool. The Launcher sets WINEDLLOVERRIDES=version=n,b when starting SCPSL so MelonLoader’s version.dll injects.
• Native Linux Launcher: loadouts run through umu-run from umu-launcher, with a per-loadout Wine prefix at GameRoot/wineprefixes/<loadout>/ and PROTONPATH=GE-Proton.

If the native Launcher reports that umu-run is unavailable, install umu-launcher using the hint shown in the Launcher.

Path differences on Linux

The Launcher and the game process may resolve user-data folders through different native and Wine paths. See Runtime Paths and User Data if identity or cache files appear out of sync.

Killing a stuck game

If the modded game stops responding, use Kill in the Launcher. This force-closes the process and should be used only when a normal quit is not possible.

Add the Launcher as a non-Steam game

For Steam overlay support inside the modded game:

1. Steam -> Games -> Add a Non-Steam Game to My Library.
2. Browse to Anomaly.Launcher.exe.
3. Optionally rename the shortcut to “Anomaly”.
4. Force a Proton compatibility tool for the shortcut.

Start that shortcut, then launch your loadout from the Launcher.

Next

Updating and Reinstalling.