Install and connect

Before you start

• Install DOOM Eternal through Steam. Install The Ancient Gods if your room uses DLC missions, equipment or enemies.
• Download the DOOM Eternal Archipelago release that matches the room's APWorld. Extract the whole archive into its own folder. Keep client/ beside the launcher.
• Have the room's server address, player name and password, if required.
• Close DOOM Eternal during mod installation, updates and repairs.

The launcher installs Sentinel Core and downloads the mod installer after asking for your consent. It checks downloaded files before using them. A local development package can include a separate Core folder: select its distribution.json with HELP → LOCAL CORE… before setup. Keep that folder intact.

If you have Meathook's XINPUT1_3.dll in the game folder, keep a backup and move that known Meathook file out before setup. For a file from another mod, follow that mod's uninstall instructions. The launcher preserves files it cannot identify.

Get an AP room

If someone has already generated and hosted your room, go to Join the room.

To create one:

1. Open doometernal.apworld with Archipelago Launcher and restart Archipelago Launcher.
2. Open DoomEternalArchipelagoLauncher.exe on Windows, or DoomEternalArchipelagoLauncher on Linux. Choose CREATE PLAYER.
3. Enter your player name, choose options and save the player YAML.
4. Generate and host a room using that YAML in Archipelago, or give it to your host.

Use the APWorld bundled with this release. The room fixes your campaign options during generation; editing your YAML afterward does not change a running room.

Join the room

1. Open the DOOM launcher and choose JOIN ROOM.
2. Confirm the detected game and save folders. Use CHOOSE GAME FOLDER and BROWSE if detection fails. Select the installation containing DOOMEternalx64vk.exe.
3. Enter the server address, player name and optional password, then connect.
4. Wait for SESSION to show your player and room. If it requests setup, choose INSTALL ROOM PACKAGE or UPDATE ROOM PACKAGE.

The launcher prepares a mod for this room and your player. Do not copy a mod from another room, even if its options look the same.

Windows installation

1. Approve the EternalModInjector download, or select a verified local copy when prompted.
2. Wait for the injector command window. Complete its prompts and close it after it reports a successful installation.
3. Return to the launcher and confirm that installation succeeded.
4. Wait for SETUP READY. Start DOOM Eternal through Steam and keep the launcher open. Choose the normal game launch, not Steam's Play DOOM Eternal with mods option.

The launcher places the room mod in the game's Mods/ folder and installs the matching sentinel_core.dll and msimg32.dll. You do not need to copy DLLs by hand. If automatic installation fails, use the manual steps below.

Windows manual installation

1. Open the Windows EternalModInjector page. Download the installer version requested by the launcher.
2. Extract its contents into the DOOM Eternal installation folder. EternalModInjector.bat and EternalModManager.exe belong beside the game executable; its supporting files belong in base/. Do not put the installer ZIP in Mods/.
3. Let the launcher prepare and stage your room mod in Mods/.
4. Set :AUTO_LAUNCH_GAME=0 in EternalModInjector Settings.txt so installation finishes before the game starts.
5. Run EternalModInjector.bat, complete its prompts and wait for success.
6. Return to the launcher. Choose I COMPLETED MANUAL INSTALLATION and confirm.
7. Wait for SETUP READY, then start the game through Steam.

Linux / Steam / Proton installation

Run the Linux launcher outside Proton. Steam runs the Windows game inside Proton.

1. In Steam, choose the Proton version under DOOM Eternal → Properties → Compatibility.

2. If detection fails, use JOIN ROOM → PROTON EXECUTABLE → BROWSE and select that version's file named proton.

3. Approve the EternalModInjectorShell download or supply a verified local copy. Complete the installer prompts and confirm success.

4. In SESSION, copy the Steam launch option into DOOM Eternal → Properties → Launch Options. It has this form:

   WINEDLLOVERRIDES="msimg32=n,b" "/absolute/path/to/client/run_bridge.sh" %command%
   

5. Check that the path points to the extracted release's client/run_bridge.sh. Wait for SETUP READY and start DOOM Eternal through Steam.

Proton Experimental often stores proton under ~/.local/share/Steam/steamapps/common/Proton - Experimental/. GE-Proton installations often use ~/.local/share/Steam/compatibilitytools.d/. Use the version selected in Steam. This candidate still needs testing on a real Linux/Proton installation.

Start, stop and resume

Wait for the launcher to finish preparing the AP save before starting the game. Disable tutorials in the game settings and use the campaign prepared for your connected player. Check SESSION for the game connection and item activity after loading a level.

Exit DOOM Eternal normally before disconnecting. On your next session, choose RESUME, enter the room password if asked, and wait for setup checks before starting the game. Use one launcher/bridge for each game profile.

Use AP SAVE… to inspect or back up the room's AP campaign. Do not replace it with a save from another room. See Gameplay and options for inventory recovery.

Details / Copy details shows the room's metadata and native save paths, including missing or inaccessible files. Back up local files copies available files for this room with DOOM closed and verifies the archive. Create backup requires an active AP game session. Restore compatible backup accepts a matching backup. New DOOM save in this room requires confirmation and a verified local backup; server progress stays intact. A local file copy does not verify that DOOM can load it.

Fix a problem

Problem	What to do
Cannot connect	Check the server address, player name and password with the host. Use the player name from generation.
Game or saves not found	Browse to the Steam game installation and its Windows save directory, or the save directory inside the selected Proton prefix.
Setup requests an update	Close DOOM and choose UPDATE ROOM PACKAGE. Check that the host generated with the matching APWorld.
Core missing or mismatched	Close DOOM. Open HELP → REPAIR CORE. For a local candidate, choose its distribution.json with LOCAL CORE… first.
Installer failed	Read the installer window's error, close DOOM and retry. On Windows, follow the manual installation steps if download or automation fails.
Game starts but does not connect	Keep the launcher open and connected. On Proton, check the copied Steam launch option. Run HELP → CHECK SETUP.
AP save needs attention	Close DOOM. Open AP SAVE… and inspect the reported problem or restore a matching backup before retrying.
An item seems missing	Load a level, choose RESYNC INVENTORY, return to DOOM and unpause. See the gameplay guide.

If the problem continues, use HELP → SAVE SUPPORT REPORT or Report a Problem. Reports exclude save contents and redact secrets; review the report before sharing it. FIX SETUP previews the repairs it can apply. UNINSTALL MOD removes the room mod; keep backups before changing a working installation.