You wouldn''t need to know 3D programming, depending on what you want to do. The most 3D you would need to know is not very much. The source files that are supplied are just one big example of how to do things. To find out more on mod development, you''ll want to go to a good site about the game you''ll be using; the gamespy network has good ones. The main site or hosted sites will most likely have resources on how to make mods.