Install the Modded Client

The Anomaly Launcher drives install, reinstall, and uninstall. You pick a game build or local source, choose a GameRoot for game files and loadouts, and the Launcher prepares one or more modded SCP:SL installs under that GameRoot.

Launcher and game files are separate

Anomaly.Launcher.exe can live anywhere. Game builds, mod caches, loadouts, and Linux Wine prefixes live under the user-chosen GameRoot. See Loadouts and Game Versions for the full layout.

Quickstart

1. Download the Launcher from the Anomaly Launcher releases page. Choose Anomaly.Launcher-win-x64-vX.X.X.zip for Windows or Anomaly.Launcher-linux-x64-vX.X.X.zip for Linux.

2. Extract the zip somewhere convenient. The launcher binary does not need to sit inside the game install. Do not put it inside your vanilla SCP:SL directory.

3. Open the Launcher and choose a GameRoot. This is where Anomaly stores games/, mods-cache/, loadouts/, and, on Linux, wineprefixes/.

4. Go to Game Versions and install a build. Pick a supported build from the list, or choose Use local directory… if you already have a vanilla SCP:SL folder to use as the source.

5. Wait for install to finish. The Launcher downloads verified install resources, applies Anomaly compatibility changes, installs MelonLoader, verifies required files, and generates first-run loader data.

6. Create or select a loadout, then launch it. The first launch of a game version can still be slower than later launches while MelonLoader finishes setup.

Game Versions tab

The Game Versions tab shows known SCP:SL builds and marks which ones are present under GameRoot/games/. It also exposes:

• Install for a selected build.
• Use local directory… for an existing vanilla SCP:SL folder.
• Reinstall / Sync for an installed build.
• Uninstall to remove that build’s game files while preserving shared launcher data and loadout state where possible.

What the installer does

The progress dialog shows the install phases. At a high level, Anomaly:

1. Copies or downloads the selected game files into GameRoot/games/<version>/.
2. Downloads verified install resources when needed, using a local cache for repeat installs.
3. Applies compatibility changes required for Anomaly and MelonLoader.
4. Installs the pinned MelonLoader version.
5. Verifies Anomaly files and mod folders.
6. Runs a first-time setup pass so generated loader assemblies are ready.
7. Writes install-state files for the Launcher’s installed-build panel.

If a failure happens while compatibility changes are being applied, the installer attempts to roll back changed game files. Your vanilla Steam install is not modified.

The first-run setup is intentionally isolated: the installer temporarily moves any existing Mods/ out of the way, creates a fresh Mods/ containing only Anomaly.FirstRun.dll, launches once to generate Il2Cpp assemblies, then restores the original Mods/. Your loadout and local mods are not loaded during that installer-only pass.

Installed layout

After install, the selected build lives under your GameRoot:

GameRoot/
|-- games/<gameVersion>/
|   |-- SCPSL.exe
|   |-- SCPSL_Data/
|   |-- MelonLoader/
|   `-- version.dll
|-- mods-cache/
`-- loadouts/

Shared identity, launcher caches, and crash reports live under %APPDATA%/Anomaly/. See Runtime Paths and User Data for the full layout.

Reinstall is safe for loadouts

Repository mods and local dev files live in the loadout/cache model rather than being manually owned by one game folder. Reinstalling a game version should not delete GameRoot/loadouts/ or GameRoot/mods-cache/. Back up important local DLLs or user data before deleting the whole GameRoot manually.

Next

First Launch, Profile, and @anomaly Identity.