Legacy:Package Extension Catalog

These are the various file extensions to package files sorted by game.

All Unreal Packages share the same internal Package File Format, but:

• the format might be slightly different in different builds or in different games
• .UC file, .ogg, .mp3, and various video files (.avi, .etc) are not Unreal packages

This means that technically most things can go into any package. For example textures can go in a .uax sound package, or static meshes be put into a .ut2 map package instead of a .usx static mesh package. This is how you can use the "MyLevel" pseudopackage to include custom content in a map, without having to make separate resource files.

Typical contents are just that, typical. .U packages especially, tend to have things besides UnrealScript binaries and sources in them.

All Unreal Engine Games

These extensions should work with any Unreal engine game.

Extension	Description	Typical Contents
uc	UnrealScript Class Source	UnrealScript in plain ASCII Text. (This is not an Unreal package format. Here for reference only.)
u	UnrealScript Package File	Compiled UnrealScript and UnrealScript source text (without default properties). Often also contains Sounds, Textures, Meshes and Static Meshes
utx	Textures	Textures, sometimes compressed, and mipmaps
uax	Audio (sound) files	Wave sound files
uz / uz2	Compressed package	Contains a compressed version(s) of any package for faster downloads.
uxx	Cached package	Cached downloaded package. The actual file extension is stored in Cache.ini in the game's Cache directory. This can be any of the other types of packages mentioned on this page.

First generation

These extensions are used in Unreal1, Return to NaPali, and Unreal Tournament in addition to the universal extensions.

Extension	Description	Typical Contents
unr	Unreal Map File	Map geometry and texture references as well as instances of any actors placed in map. Can also contain compiled UnrealScript code, sounds, textures, music, etc.
umx	Unreal Music Files	Contains a module music file. (usually S3M, IT or XM)

Unreal Tournament 2003

These extensions are used in UT2003 in addition to the universal extensions.

Extension	Description	Typical Contents
ut2	UT2003 Map File	Map geometry and texture references as well as instances of any actors placed in map. Can also contain compiled UnrealScript code, sounds, textures, etc.
usx	Static Meshes	Contain geometry and texture references for static meshes.
ukx	Skeletal Meshes	Contains skeletal meshes.
uvx	Saved Ladder Profile	Contains information about the player's progress in UT2003's single player mode.
ogg	Ogg Vorbis Music File	(This is not an Unreal package format. Here for reference only.)

Unreal 2: The Awakening

These extensions are used in U2 in addition to the universal extensions.

Extension	Description	Typical Contents
con	DirectMusic CONtainer object	Music in Microsoft's proprietary "module" format that DirectX can read and use for playback
dlg	Unreal 2 Dialog file	Dialogs... something?
ogg	Ogg Vorbis Music File	This is not an Unreal package format. Here for reference only. See OGG File.
u2s	Unreal 2 Script File	Pawn scripting file, see AI Scripting for info
ugx	Storage of golem edd files	used to import the models in golem edd into the unreal ed program.
un2	Unreal 2 Map File	Map geometry and texture references as well as instances of any actors placed in map.
usx	Static Meshes	Contain geometry and texture references for static meshes.

Deus Ex

These extensions are used in Deus Ex in addition to the universal extensions.

Extension	Description	Typical Contents
dx	Deus Ex Map File	Map geometry and texture references as well as instances of any actors placed in map.

Wheel of Time

These extensions are used in the Wheel of Time in addition to the universal extensions.

Extension	Description	Typical Contents
wot (?)	Wheel of Time Map File	Map geometry and texture references as well as instances of any actors placed in map.

Rune, Rune: Halls of Valhalla

These extensions are used in Rune and Rune: Halls of Valhalla in addition to the universal extensions.

Extension	Description	Typical Contents
run (?)	Rune Map File	Map geometry and texture references as well as instances of any actors placed in map.

Undying

These extensions are used in Undying in addition to the universal extensions.

Extension	Description	Typical Contents
sac	Undying Map File	Map geometry and texture references as well as instances of any actors placed in map.

Star Trek DS9: The Fallen

These extensions are used in Star Trek DS9: The Fallen in addition to the universal extensions.

Extension	Description	Typical Contents
dsm	DS9: The Fallen Map File	Map geometry and texture references as well as instances of any actors placed in map.

Mobile Forces

These extensions are used in Mobile Forces in addition to the universal extensions.

Extension	Description	Typical Contents
???	Mobiles Forces Map File	Map geometry and texture references as well as instances of any actors placed in map.

America's Army: Operations

These extensions are used in America's Army: Operations in addition to the universal extensions.

Extension	Description	Typical Contents
aao	Army Ops Map File	Map geometry and texture references as well as instances of any actors placed in map.
usx	Static Meshes	Contain geometry and texture references for static meshes.

Land of the Dead

These extensions are used in Land of the Dead, in addition to the universal extensions:

Extension	Description	Typical Contents
dz	Land of the Dead Map File	Map geometry and texture references as well as instances of any actors place in map.

Related Topics

• Unreal Engine
• Unreal Engine versions
• Engine Directory Structure
• Package
• Package File Format
• File Format

Discussion

Githianki: I don't have the references with me since I am not at my gaming rig, so feel free to fill these in. I can't conclusively recall some of the map extensions right now. I know there are more games, like the Star Trek stuff but I don't have those or even know the full names. The format should be self-explanitory by looking at the edit box. I left some reference markup in the first table. It is all shamelessly ripped from the markup page anyway. I left out Unreal Championship and the PS2 titles since they can't be edited and who knows if the same file system was used in some cases anyway? Category:Legacy To Do So this shows up if someone else wants to help out. It will take me awhile to get all info for the games I have (Unreal,NaPali,Ut,UT2003,Wot,RUNE,RUNE:HOV) I could get Army Ops too but I had to delete it to have room for UT2003 :)

Tarquin: There's probably some refactoring could be done between Engine Directory Structure, Package and here. Package is currently a redirect to Package, might be better to have a package overview page there.

Wormbo: Done some cleanup with the Wiki Markup on this page. It's cool stuff, but try not to overuse it. :)

Legal: Added Deus Ex, one of the best games EVER!

Githianki: Yeah I really got into the markup but it seemed useful here. I see how you cleaned it up so now I know the minimum needed. The markup page has lots of extra code which is where I lifted from. Maybe someone should clear that up or you'll be doing overtime. Fixed some typos. Added in .uz and .uxx extensions to universal. Can't believe I forgot Deus Ex. doh! Also, what was the scoop on .umx support in Ut2003 versions of the engine? Is it out or does the new opensource stuff support it? Also I think .uc can be RTF too. If so that should go back up there.