What is a ...?

Modification or "mod"
1. (Technically) A modification is a non-commercial add-on to a game, usually freely available, which alters the game in some way.
2. (Most people's usage) A mod is a non-commercial add-on to a game, usually freely available, which alters gameplay in some way. This means ChaosUT is a mod, because it gives you different weapons and changes gameplay as a result, but a player model like SpaceMarine40K is not considered to be a mod, because it just changes your appearance without altering the "rules" of UT.
A UT player model is an add-on consisting of a 3D mesh made from triangles, one or more skins for that mesh, and the UnrealScript necessary to use it in the game to represent you, another player or a bot. Models built in to UT include Male Soldier, Female Commando and Boss, while add-on models include Space Marine 40K and Riot Girl.
A skin is a texture (image) designed to be wrapped round the surface of a particular 3D mesh. For example, Male Soldier's skins include Marine, War Machine and Raw Steel. Add-on skins are available for all the basic UT models and for most add-on models.
A mutator is a piece of UnrealScript run by a UT server to alter or "mutate" gameplay. For example, a mutator can replace all weapons with something else (Instagib), alter physics (Low Gravity), and so on. Many mods are implemented as mutators.
A UMOD is a standard installer format used by Unreal Tournament, as well as recent Unreal I patches, which comes in a file with the extension ".umod". The name stands for Unreal Module. It is understood by the installer "Setup.exe" found in the \System\ folder on Windows versions of Unreal and UT, and by third-party installers on Mac and Linux UT.
ZIP file
Most mods, models and skins are distributed as a ZIP file containing a UMOD file. A ZIP file is a compressed file containing other files, and takes less time to download than its uncompressed contents would. Before you can use the contents of a ZIP file, you need to "unzip" (decompress) them, using a program like Power Archiver or Winzip (Windows), Stuffit Expander (Mac), or the zip and unzip programs from Info-Zip (any platform, but they're particularly suitable for Linux).
UT patches are official updates released by Epic Games to fix bugs, prevent multiplayer cheating and occasionally even add features. Patches are supplied as an executable file (no extra software is required, you just download the patch and run it), with the exception of the latest patch, which (for Windows) is supplied as a ZIP file containing an executable. You should download and install the latest UT patch (at the time of writing, this is identified as version 436) to fix bugs and make mods more reliable.
Bonus Pack

Epic and Digital Extremes have released four free Bonus Packs so far. Bonus Pack 1 (also known as "the Bonus Pack", because for several months it was the only one around) includes 3 models (Skaarj Hybrid, Nali and Nali Warcow), many maps and some mutators (Relics). Bonus Pack 2 (the Digital Extremes Bonus Pack) includes 2 maps and some more mutators.

Bonus Pack 3 (the Inoxx Map Pack) contains several maps by Epic mapper Inoxx (creator of Facing Worlds and Pressure, among others) and Bonus Pack 4 contains 2 models (Xan Mk.II and WarBoss) and several more maps.

Bonus Packs, like most mods, are distributed as a ZIP file containing a UMOD (with the exception of Bonus Pack 2, which contains two maps as plain .unr files, and a tiny UMOD for the mutators).

There is also an unofficial Assault Bonus Pack, which alters the Assault game type and includes several great assault maps. This is not an Epic product but is well worth downloading anyway.

Installation and uninstallation

UMOD files (*.umod)

On Windows UT these should be easy - the UT install associates them with [UT folder]\System\Setup.exe, so Windows users with a correctly installed copy of UT should be able to just double-click the .umod file and follow the instructions (if asked for your UT folder, always choose the base folder, such as C:\UnrealTournament, and not a subfolder like C:\UnrealTournament\System).

If, when you double-click a UMOD file, you get the Windows "Open With" dialog, try downloading my UT Registry fixing utility (27.4 KB compressed Windows executable), which sorts out the Windows Registry keys UT should create when you install it.

To uninstall, run [UT folder]\System\Setup.exe and select the mod(s) you want to uninstall. Don't uninstall "UnrealTournament" unless you want the whole of your UT folder to disappear!

For mods like Advanced Model Support, which other mods depend on, this should automatically uninstall everything which wouldn't work without it too (e.g. removing AMS will also remove Space Marine 40K and Gollum), but if mod authors have been careless, there might be some mods left over which no longer work; you'll have to remove them separately, by the same method.

Linux users can install UMODs using UMODPack, a set of Perl scripts containing command-line and GUI installers. I usually find the command-line version (umod) is more reliable than the X GUI (xumod) when dealing with badly-made or Windowsish UMODs (::sigh:: spaces in filenames).

If, like me, you use Debian, just use whatever package management tool you prefer (dselect, aptitude, apt-get...) to download and install the package "umodpack". It's in the stable distribution as of Debian 3.0.

For recent mods, you will need to edit System/Manifest.ini with your favourite text editor and correct the UT version; UMODPack assumes you only have version 400, but if you're trying to use mods, you really should have downloaded the version 436 installer from Loki Games by now.

I assume anyone who can get games working on Linux is intelligent enough to work out which version they just installed, and also intelligent enough to realise that setting a higher version number than you actually have is A Bad Thing.

See man umod for more information.

Mac UT users should already have a UMOD installer made by Westlake Interactive. I've never used Mac UT, but I assume it's similar to the Windows installer. If you have trouble, try osX, a Mac UT site hosted by BeyondUnreal.

Individual files (*.utx, *.int, *.u, *.unr, *.uax, *.umx etc.)

If you downloaded a ZIP file containing individual files (many maps and a few skins are still packaged this way), here's where to put them. All should go in subfolders of your Unreal Tournament folder.

  • *.txt, *.htm and *.html files are the instructions. Read them now. If you want to keep them for later reference, put them in the Help subfolder.
  • *.u, *.int and *.ini files are UnrealScript-related. They go in the System subfolder.
  • *.utx files are textures and images, and go in the Textures subfolder.
  • *.uax files are sound packages, and go in the Sounds subfolder.
  • *.umx files are digital music and go in the Music subfolder.
  • *.unr files are maps and go in the Maps subfolder.

To uninstall, you'll have to remember what you installed and delete the files yourself.

Why doesn't it work?


All mods should come with a text or HTML file containing the instructions. Read it.

If the mod is packaged as a UMOD, make sure you entered the correct Unreal Tournament path when you installed it. All UMODs should be installed to the base UT folder (like C:\UnrealTournament), not to a subfolder (like C:\UnrealTournament\System).

If the mod is packaged as a collection of individual files with extensions like *.utx, *.unr and *.u, make sure you put them in the correct folders (above).

No mod (this includes skins and models) will work in multiplayer unless it is installed on the server. See ServerPackages below for details of how to set up mods if you intend to run a server.


If you're trying to use the Boss (Xan), Xan Mk.2 or Warboss models, be aware that you may need to have completed the game first. You can cheat and make UT give you these models without actually completing the game. The easiest way is probably to download, unzip and install this UMOD file: HasBeatenGame.umod.zip (737 bytes).

If you don't mind using Notepad or some other plain text editor, you can get the same effect by adding the following to your User.ini file ([UT folder]\System\User.ini on Windows and Macs):


Note: If you cut and paste this from your web browser, you might need to remove an extra space from the end of each line. There shouldn't be any spaces at the end of either line.

Linux users need to edit $HOME/.loki/ut/System/User.ini, where $HOME represents your home directory - Linux UT is a real multi-user app and has separate configuration files for each user.


If you're trying to use skins for a custom model (any model except (Male/Female) (Soldier/Commando), or Boss) you need to install the model first. UT is not like Half-Life or Jedi Knight where all skins include the model. For example, to use the Metallian Skaarj Hybrid skin (TSkMSkins_Skar.utx) you need to have the Skaarj Hybrid model, which is part of the first Epic Bonus Pack.

Skins for the Bonus Pack 4 models (WarBoss, Xan II)

You need to download and install my unofficial Bonus Pack 4 fix for skins designed for these models to show up. You then need to select "Warboss [fixed]" or "Xan Mk.II [fixed]" from the Class menu. Remember that, as far as UT is concerned, these are entirely new custom models, so they won't work in multiplayer unless the server has them too - use the original, non-fixed models if playing online, for example.

How do I make my new skin work in the single-player Tournament?

You can't. Custom models and skins only work in practice sessions (botmatches) or multiplayer. Multiplayer only works if the server has the skin and has placed it in their ServerPackages list.

Making skins

How do I make skins for the Bonus Pack 4 models?

First, download my fix (as described above), since you'll need it to see your new skin in-game. Next, you'll probably want to extract the original skins to use as a template. To do this, open up UnrealEd, open the texture browser and select File/Open. Change the filter to "All Files (*.*)" and go into the System folder. Select "SkeletalChars.u". Right-click on each texture and export as usual. Note that the texture names Epic used will not work with my fix - read the document included with the fix (bp4fix313.htm) for details of the names you should use.

Extra note: The first Xan Mk.II skin I saw wasn't actually complete. Skins for these two models need one talktexture (64x64 image of the face, used for the chat area) for each colour - that's 5 per skin, not just 1 as usual. If you want to make the skins work properly, have a look at my test skins, which look terrible but include a complete set of textures. Please use these as a guide to what you have to include.

Server Packages

The Unreal game engine maintains a list of allowed packages for the server. These determine what models and skins the server is allowed, among other things.

If the server doesn't have enough server packages, players will be unable to use custom skins and models, and the server operator will be unable to use mods and custom mutators.

On the other hand, every player (client) joining the server must have all the server packages to play on your server. If they have the same package, fine. If they have a different package with the same name, they will be thrown out with a "Package Mismatch" error. If they don't have the required package, they will be made to auto-download it (this is slow and frustrating for all except the smallest packages).

How do I change my server packages?

Unfortunately, you can't do this while UT is running, so exit if it's running already. Open up System\UnrealTournament.ini with Notepad or similar and look for a heading [Engine.GameEngine].

Under this heading you should see several lines in the format ServerPackages=SomePackage. Delete any you don't need (be careful!) and add similar lines for each package you do need. The bit after the equals sign should be the name of the package file without the extension, so to add RiotGirl.u and RiotGirlSkins.utx to your server, you should add ServerPackages=RiotGirl and ServerPackages=RiotGirlSkins.

Important note: If you copy and paste server packages or any other settings from a website, be careful - most web browsers will add a space after each line. You need to delete these extra spaces for UT to work.

Correct: "ServerPackages=SomeMod"

Wrong: "ServerPackages=SomeMod " (note the space after SomeMod)

Linux users need to edit $HOME/.loki/ut/System/Unrealtournament.ini instead, where $HOME represents the home directory of the user who will be running the game. If you have a multi-user Linux box, everyone who'll be running a server needs to edit their own ServerPackages; if you have a "daemon" userID which will be used to run dedicated servers, you need to edit its copy of the INI file too.

What needs to be in my server packages?

Whatever happens, you need the following for UT to work:


For Epic Bonus Pack 1, you need the following as well:


For Epic Bonus Pack 4, you also need the single line "ServerPackages=SkeletalChars".

Maps and their resources don't need to be in the server packages - the server automatically assumes the current map and all its resource files are included.

Models, skins, gametypes, mutators and voicepacks do all need to be in the server packages.