Use the Unreal Tournament 3 level editor
How to use the Unreal Tournament 3 level editor A basic tutorial on using the level editor in Unreal Tournament 3 to create custom playable Death Match levels and maps. This tutorial series covers:
Navigation ,Kismet, Matinee, Bot Pathing, Level Construction, Texturing, Triggers,
Cooking Maps, Particle Systems, Materials, and the Material Editor