
RANDOMIZE SEED Randomly picks a new seed. The locations of human-built features such as roads and NPC faction towns may persist on multiple uses of the same seed, or they may vary somewhat from one use to the next. A given seed always produces the same geographical features such as land masses, rivers and mountains. SEED A random seed is provided, but you may enter your own. The world generation screen appears during the creation of a new colony. An ancient society is then shallowly simulated to generate ancient roads, and modern settlements and roads are generated (often alongside ancient roads). When generating the world, the land masses form first, followed by rivers. When reloading the world after opening the colony, the game shows a loading screen.

The seasonal differences are also less pronounced near the equator, with there being a permanent summer in it. Temperatures in regards to proximity from the equator are also correct with hotter biomes being more central and colder biomes being closer to the poles. Time zones are also modelled as the world actually physically exists and is fully interactive. 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.
