There are sliders for overall planet temperature and overall rainfall, with the result of changing them being true to what would happen in real life. For example, some biomes feature a large amount of mountains, while others are full of grasslands. Each world is uniquely filled with multiple biomes that change what the world looks like and how it behaves. Worlds in RimWorld are generated from either random or user-provided seeds that allow for a completely new experience every time.
