>>141191If the game has modding tools or native modding support or is open-source then modding can be very easy if you just want to swap assets like sprites/textures, sounds and text. 3D models are much more of a pain in the ass to work with if you aren't very experienced with Blender or 3ds Max. If the modding tools give you access to scripts that control game functionality, there's lots of things you can change with very little to no programming knowledge like health values, timer values, spawn coordinates, swapping vehicle/weapon/item/character IDs, etc.