Installing Mods on Your IW4x Dedicated Server

Installing Mods on Your IW4x Dedicated Server

IW4x supports two types of server-side content: full mods loaded through fs_game, and server-side GSC scripts placed in userraw/scripts/. This guide explains both approaches, how IWD files work, and how to install specific mods.

Understanding IW4x Mod Architecture

IW4x inherits the MW2 modding system, which organizes content into two categories:

Full mods (fs_game): Stored in a subdirectory of mods/, loaded at server startup via the +set fs_game "mods/modname" launch parameter. A mod folder typically contains .iwd files (zip archives with game assets, scripts, and resources). Only one mod can be active at a time per server instance.

Server-side GSC scripts (userraw/scripts/): Plain .gsc script files placed in the userraw/scripts/ folder. They load automatically without setting fs_game. These are best for small tweaks, custom game logic, or utility scripts that don't need custom assets.

IWD files: .iwd files are renamed ZIP archives. You can open them with any ZIP tool to inspect their contents. They contain compiled GSC scripts, textures, sounds, and other game assets. The filename matters — IW4x loads IWD files in alphabetical order, and files prefixed with z_ are loaded last (highest priority).

File Structure

MW2ServerFolder/
├── mods/
│   ├── mp_bots/              (full mod — Bot Warfare)
│   │   └── z_svr_bots.iwd
│   └── my_custom_mod/        (another full mod)
│       └── z_my_mod.iwd
└── userraw/
    └── scripts/
        ├── my_gsc_tweak.gsc  (server-side script, no fs_game needed)
        └── another_script.gsc

Installing a Full Mod

Step 1: Place the Mod Folder

Download your mod of choice. Most mods distribute as a folder named mp_modname or modname. Place this folder inside the mods/ directory in your server folder. If the mods/ directory doesn't exist, create it.

Example for Bot Warfare:

MW2ServerFolder/mods/mp_bots/z_svr_bots.iwd

Step 2: Edit DedicatedServer.bat (or launch script)

Add +set fs_game "mods/mp_bots" to the launch command. The full line should look like:

iw4x.exe -dedicated +set fs_game "mods/mp_bots" +set sv_lanonly "0" +set net_port "28960" +exec server.cfg +set party_enable "0" +map_rotate

The fs_game path is relative to the game root. On Linux, the path is case-sensitive — the folder name must match exactly.

Step 3: Restart the Server

Stop and restart the server. The mod loads on startup. In the server console, you should see log entries confirming the mod's IWD files were loaded.

Step 4: Verify the Mod is Active

Connect to the server with an IW4x client. The mod should appear in the server browser under "Game" or be indicated by a custom server name. You can also run rcon status — if the mod has a custom status string, it will appear there.

Switching Back to Vanilla

To run without a mod, set fs_game to an empty string:

iw4x.exe -dedicated +set fs_game "" +set sv_lanonly "0" +set net_port "28960" +exec server.cfg +set party_enable "0" +map_rotate

Installing Server-Side GSC Scripts

GSC scripts in userraw/scripts/ load automatically when the server starts. You don't need to set fs_game.

1. Create the userraw/scripts/ directory if it doesn't exist.
2. Place your .gsc files inside it.
3. Restart the server.

Server-side GSC scripts are useful for:

• Custom game rules or win conditions
• Player stat tracking
• Anti-cheat supplementary checks
• Chat command handlers
• Map-specific logic

Important: userraw/scripts/ scripts run on the server and affect all players but don't require the client to have any files. Full mods (fs_game) that contain client-side assets (textures, sounds) require all players to have the mod files or to download them from the server (via FastDL if configured).

Common IW4x Mods

Mod	fs_game Path	Source
Bot Warfare	mods/mp_bots	github.com/ineedbots/iw4_bot_warfare
Custom scripts	n/a (scripts go in userraw/scripts/)	Various community sources

For the complete Bot Warfare setup guide, see Installing the Bot Warfare Mod on IW4x.

Troubleshooting Mod Loading

Mod not loading / server running vanilla

• Verify the fs_game value in your launch command matches the exact folder name (case-sensitive on Linux).
• Check that the folder exists at mods/[modname]/ inside your server directory.
• Ensure the folder contains at least one .iwd file.

"Could not find zone" or crash on start

• The mod may require specific map IWD files that aren't in your main/ folder.
• Check whether the mod has DLC map dependencies and whether you have those IWD files.

Players can't connect to modded server

• Players connecting to a server with fs_game set may need the mod's client files (textures, custom sounds, etc.). Purely GSC mods (scripts only) don't require this.
• Check the mod's documentation for what files clients need.

Multiple mods

IW4x only supports one active fs_game mod at a time. To combine mod functionality, merge IWD files from multiple mods into a single mods/combined/ folder, being careful about file naming conflicts.

Related

• Installing the Bot Warfare Mod on IW4x
• Installing Your IW4x Dedicated Server on Windows
• Host an IW4x (MW2) server with DustBowl.Games