World generation

From RimWorld Wiki
Revision as of 15:24, 12 October 2017 by Jimyoda (Talk | contribs)

Jump to: navigation, search
Basics Menus Game Creation Gameplay Pawns Plants Resources Gear Mods
Game Creation Scenario system AI Storytellers World Generation Biomes

Worlds in RimWorld are generated from either random or user-provided seeds that allow for a completely new experience every time. Each world is uniquely filled with multiple biomes that change what the world looks like and how it behaves. For example, some biomes feature a large amount of mountains, while others are full of grasslands.

As of Alpha 16 (December 20th, 2016), Part of the world system's overhaul includes sliders for overall planet temperature and overall rainfall, with the result of changing them being true to what would happen in real life. Time zones are also modelled as the world actually physically exists and is fully interactive. 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.

In Alpha 17, when reloading the world after opening the colony, the game now shows a loading screen.

Generation process

Biomes are types of area on a planet, characterized by their terrain properties, climate, flora and fauna, diseases and special challenges. Each world tile has one particular biome.

There are ten biome types in RimWorld, divided into three categories: Moderate, Arid and Cold.

A16 World Map

The following diagram is a simple chart of biomes by intensity, and therefore you could view this to see which biome could best suit your experience or playstyle: Biome Intensity Diagram

When generating the world, the land masses form first, followed by rivers. An ancient society is then shallowly simulated to generate ancient roads, and modern settlements and roads are generated (often alongside ancient roads).

Create world

The world generation screen appears during the creation of a new colony.

Seed A random seed is provided, but you may enter your own. A given seed always produces the same map layout:

  • ludeon: USA

Randomize seed Randomly picks a new seed.

Globe coverage What percentage of the overall globe is generated. Larger globe coverage generates a fuller world, but takes a longer time to load up, and can also impact performance on lower-end systems.

Configurable map sizes:

  • 5% (Dev Mode)
  • 30%
  • 50%
  • 100%

Generate Click to continue with the current settings.


Allows choosing between map sizes and starting season:


  • 200 x 200 (40,000 cells)
  • 225 x 225 (50,625 cells)


  • 250 x 250 (62,500 cells)
  • 275 x 275 (75,625 cells)


  • 300 x 300 (90,000 cells)
  • 325 x 325 (105,625 cells)


  • 350 x 350 (122,500 cells)
  • 400 x 400 (160,000 cells)

Landing site

The world will be made up mostly of hexagons and a few pentagons, then the 'Select landing site' screen appears. Clicking a tile will show its information with its average temperature, biome, elevation, terrain and rainfall amount. Clicking the Mode button (default is 'Full') offers the choice to view the map in a special heat map. Tiles are coherent to their neighboring tiles, by following alike patterns. Each biome has its own flora, fauna and growing periods.

It's possible to choose between mainland and islands. There is no way to navigate directly across the seas and oceans, instead requiring Transport pods to cross the vast body of water.


There are nine biomes in Rimworld and—on a normally generated world—all of them are represented. They each correspond to specific features. Each biome is more likely to include certain features based on it's real world equivalent.


There are several main features that affect game play in that tile on a generated world. These details are listed on-screen for the selected map tile.


A map tile's distance above sea level is its elevation. Higher elevation brings with it colder weather.


The coordinates of a map tile includes its latitude which affects its temperature range and amount of daylight. In polar latitudes the sun may not set or rise completely for a long time.


Each map tile has a certain amount of rainfall, given in average number of millimeters per year. It determines how often it will rain, not counting the automatic rain after a certain number of fire tiles are on the map.


Each map tile has one of the following terrain types: Flat, Small Hills, Large Hills, and Mountains. The terrain type determines the amount of mountain will be generated on the in-game map.


Each tile has its own averages for temperature based on the biome. Only the averages are presented in the world generation menu, but can directly affect your game. The effects of temperature vary greatly; extreme heat causes your colonists to develop heat stroke, while extreme cold may freeze them so thoroughly, their corpses will never decay. Temperature is related to the other three features of a tile in a generated world. Naturally, higher elevation and a more northern biome is colder.


Each year in a Rimworld planet is separated into 4 quadrums: Aprimay, Jugust, Septober and Decembary.

The quadrums are the same across the planet, however the corresponding seasons are reversed between the northern hemisphere and the soutnern hemisphere.


In Alpha 17, there are now roads winding across the world. They double the speed of any caravans using them, and factions tend to settle near roads. Visitors, caravans, traders or raiders are also tend to arrive and leave on a road.

They come in 5 types: path, dirt road, stone road, ancient asphalt road and ancient asphalt highway. They are functionally the same, with difference only being appearance when generated on a map.

Dirt roads use packed dirt, stone roads use flagstones of the local stone and ancient asphalt roads use broken asphalt. None of these can be disassembled for resources.

Sometimes other objects will generate alongside roads, for example the ancient concrete barrier or ancient lamppost alongside the ancient asphalt highway. These serve no function except cover or disassembly for steel.


Also in Alpha 17, there are rivers that flow towards the oceans and can merge with each other. They are more likely to generate in rainy areas.

When a map is generated in a tile with a river, there will be a belt of flowing river dividing the map. The river cannot be built over or pumped dry using the moisture pump, thus effectively splitting your future bases apart.

They come in 4 sizes, huge river, large river, river, and creek. It affects the width of the river, and also the proportion of shallow moving water, which can be walked over, to deep moving water, which can't be walked over.


Pressing the 'Factions' button allows you to view the different factions in the world.

There are three kinds of faction: outlanders, tribes and pirates. There are a total of five, and a maximum of three each. You can see the relation between them and you.

Their bases tend to be located near roads, and you cannot settle right next to one.

Factions are not tied to the world seed. Pressing "back" and "Generate" again will alter the list of factions and the locations of their bases.


There are a total of 12 pentagons in the world, with the coordinates as such:

  • 31.72 S, 0.00 W
  • 31.72 N, 0.00 W
  • 31.72 N, 180.00 W
  • 31.72 S, 180.00 W
  • 0.00 S, 58.28 E
  • 0.00 S, 58.28 W
  • 0.00 S, 121.72 E
  • 0.00 S, 121.72 W
  • 58.28 N, 90.00 E
  • 58.28 N, 90.00 W
  • 58.28 S, 90.00 E
  • 58.28 S, 90.00 W

Besides being differently shaped to allow gap-free tiling of the whole world, they function no differently from regular world tiles.

Navigation & Site selection

The player can click 'Select random site' or select one of the squares in which to land and build a colony.

Keyboard/mouse controls:
Mouse Controls
Left mouse button Select location
Right mouse button Clear selection
Mouse wheel Zoom in/out
Mouse wheel (click+hold) Pan
Keyboard Controls
PageUp Zoom out
PageDown Zoom in
Arrow up or W Pan up
Arrow down or S Pan down
Arrow left or A Pan Left
Arrow right or D Pan Right