When playing press ~ and enter the following:

When your adrenaline reaches 100, you can put in these codes to gain temporary bonuses:

Start up an instant action game. Try to do it in a very open map, such as OS-Dria or OS-Dawn. Open the console (~) and type Playersonly and hit enter. This freezes everyone in the game but you. This is necessary because the fighters will fly forward even when you aren't in them. Once you enter the codes below, get in (the vehicle will start moving, so be ready) and type Playersonly again to unfreeze everyone.

Open up the console during gameplay, and enter the following code to record a demo of what you are playing. Enter the code following that to stop recording the demo. (The demo will also stop if the current game ends, or you quit playing the game) You can play this demo by clicking on the Community on the main menu, and going to the Demos tab. From there you can create an AVI of the demo, or watch it within the game.

Use these codes with the ~ console or with the Tab quick console. These codes WILL NOT WORK if you do not have the Editor's Choice/Mega Bonus Pack Vehicles (Vehicles listed here). You can download the Battle Pack from the Official UT site or Gamespot.

Use these summoning codes in the console menu midgame to summon the weapon you typed in. Also, the final code is an overall code for all Ballistic Weapons.

Speak the following using a mic to make the named bot perform the associated action:

To unlock all three secret characters without cheating, you need to beat the game on three different difficulty settings. It doesn't matter which difficulty they are as long as they are different, because if you beat the game twice on the same difficulty setting, you don't get anything.

While playing through the Single Player mode of the game, click on the Details (at the bottom). Now, at the top of the screen, there is a bar with three tabs on it. If you go to the Other Tournament Matches tab, one of the matches will be Epic Games Inc. vs. ____ (ie, Epic vs. The Corrupt). If you right click on Epic Games Inc., a sub menu will pop up with Team details. If you click on that, a small window will pop up with some information on the history of Epic.

For Level Developers:

In Unreal Editor, open up the static mesh package "cf_DE".

Look for "cf_EasterEgg"

Click it, and you will see a guy in spandex wearing a t-shirt bearing a picture of Gorge and the words "GORGEOUS GORGE"

To unlock the secret Xan loading screen, go into you User.ini file in your System folder. Then do a Ctrl+F search to find backgrounds. You should see four lines with the same words except that two lines have the same number, 2. Change the lower one so it reads 1, 2, 3, 4, and not 1, 2, 2, 4.

For people with the European version of UT2004, push the TAB key to open up the console when playing. The codes are the same as for the American version.

In your system folder is the user.ini file. Just open it with Notepad or something similar. You'll notice that most of commands are set out like this.
[Factor]
Text and Variables of that factor

There is always a gap between the commands. Make a new gap in the command lines and paste this in there.

[GUI2K4.UT2k4MainPage]
TotalUnlockedCharacters=Malcolm;ClanLord;Xan

Then you'll have all the secret characters to pick on the character select screen. This is good to use if you accidentally ruin your user.ini file and it gets reset.