Worst-case scenario: the UEd Goblin wipes the map and burns down your house.
Engine Directory Structure
Contents
The Unreal Base Directory[edit]
This directory is where the game itself is installed. By default, it's called {drive}:\{game name}, eg C:\UnrealTournament, C:\WheelOfTime etc. Throughout the Unreal Wiki, you'll see it referred to as {Base Directory}. Within this directory there are several sub directories which varies depending on the engine version.
Unreal Engine 3[edit]
Binaries\
Engine\
Config\
Localization\
Shaders\
Stats\
{prefix}Game\
Config\
CookedPC\
Localization\
Logs\
Movies\
Published\
Splash\
Src\
Unpublished\
Unreal Engine 2[edit]
Animations\
Benchmark\
Cache\
Demos\
ForceFeedback\
Help\
KarmaData\
Maps\
Music\
Prefabs\
Save\
Saves\
ScreenShots\
Sounds\
Speech\
StaticMeshes\
System\
editorres\
Textures\
UserLogs\
Web\
Script Directories[edit]
Precompiled Script[edit]
Unreal Engine 3[edit]
Precompiled scripts for this engine version will go in one of two directories:
{User Documents Directory}\My Games\{game name}\UTGame\Src
{Base Directory}\Development\Src
Unreal Engine 2[edit]
Same as for exported scripts, precompiled scripts go in package directories in the games {Base Directory}.
Exported Script[edit]
Unreal Engine 3[edit]
Exported scripts for this engine version will go in:
{User Documents Directory}\My Games\Unreal Tournament 3\UTGame\ExportedScript
Unreal Engine 2[edit]
Exported scripts for this engine version will go in the games {Base Directory}.
The User Directory[edit]
In unreal engine 3 things were changed some and it now uses the user documents directory for storing some things. As an example UT3 will use the directory:
{User Documents Directory}\My Documents\My Games\Unreal Tournament 3