I’m Nate Mangion and I’ve been world-building for most of my life, though I’ve more recently turned to digital cartography to help me creating worlds. I’ve been working on the world of Elyden for upwards of 10-years now, writing short stories and creating maps in the same world. Some of you might know me on the internet as Vorropohaiah.
World-building isn’t an easy topic as it quite literally touches on every subject imaginable: economics, geography, vexillology, physics, warfare, politics, you name it, we dabble in it. All these things are connected, each subject informing the other in intricate web that honestly should be more than enough to put anyone off world-building for good! But we’re a strange bunch and where to most creators world-building is just a means to an end (world-building to write fiction, or to create a game), to many of us world-building is the end and we just do it for the ‘fun’ of it (fun being subjective, of course)!
My area of expertise, if I can say that, is cartography, and the way geography plays a role in worldbuilding. Many political borders are drawn along natural features, such as rivers or mountain ridges (or more obviously along coastlines) - so geography shapes a country’s territories. Tectonics show us where it’s likely for a volcano to be found, and volcanic regions are known for their soil fertility, which might lead to productive farmlands, which in turn might lead to urban centres where otherwise they would not have appeared (Naples or Pompeii). The positioning of continents and mountains affect where rain will fall, which informs where a large civilisation can and cannot appear. The chance discovery of coal or oil might change the course of a nation’s history (England during the industrial age or Saudi Arabia). And so on. Good worldbuilding is informed by the real-world and my job here is to show you how when drawing a map, the place where you thoughtlessly position that river or that mountain or that gem-mine has repercussions that should not be ignored.
Approaches to cartography
When creating maps for your worlds you need to figure out what approach you’re going to take. Most commonly this is referred to as Top-down or Bottom-up.
The Top-down approach starts with the big picture and works its way down to details: world map → continental map → nation map → county map → city map. This approach is likely to give the most realistic results, but is more time-consuming, and those seeking a quicker payoff may prefer the other method. The Top-down approach is more likely to appeal to pure worldbuilders, rather than those who are worldbuilding for fiction.
The Bottom-up approach generally starts with a particular area or region - a city, nation, or part of a nation - and is expanded upon when needed. This is what you’re looking for if you’re creating a setting for an RPG or novel that’s unlikely to move to other regions, and you can spend more time concentrating on the immediate area, rather than waste time on mountain-chains half a world away!.
There is no right or wrong way, and each has it’s pro’s and con’s though I personally prefer the more thorough Top-down approach, as it allows you to create a believable world in which you can later develop cultures.
For this article I’m going to concentrate on the Top-down approach, but all parts are useful to both approaches.
The Big Picture
I won’t go into planetary characteristics like planet mass, distance from sun, etc. Though important to the Top-down approach, it’s not really in the purview of this article. Suffice it to say that choosing a binary system, or a planet with two moons, or a planet that’s twice the size of earth should realistically have lots of repercussions on worldbuilding (rotation and orbit; tides; and gravity, respectively, in case you’re interested), but I’ll let more knowledgeable people talk about such things!
For the sake of this article, the big picture refers to things like tectonics, mountains ,rivers, deserts, climate and so-on.
Note: Much of what I’m going to mention in the following sections assumes that the world is spherical. Torus worlds and flat worlds are relatively common, though come with their own rules, particularly regarding tectonics. A planet built by gods might not be constrained by the laws of plate tectonics (though if it was created long-enough ago, it still might be).
Climate is probably one of the major contributing factors to creating distinct cultures and nations that’s either taken for granted or overlooked entirely. This is one of the more difficult areas to implement in your cartography and world-building, though it is the one with the largest margin of error, if realism is an important factor in your world-building. If you ignore things like climate bands and atmospheric circulation, you could end up placing a forest in a region without the conditions to realistically support one. As always with such insights, you shouldn’t totally bind yourself to them, though it’s good to know about them so that your decisions are at least informed.
Climate describes long-term patterns in weather in particular regions. Where weather can change from day to day, climate is generally constant, excluding outside interference. Things like latitude, terrain and nearby oceans all affect climate, which is what makes it tricky to implement in world-building.
You can divide both northern and southern hemisphere into three distinct bands between the equator and 30 degrees, 30 degrees and 60 degrees, and 60 degrees and 90 degrees. These can be called tropical, temperate and arctic bands. These bands are also used to calculate atmospheric circulation, as seen below. Flora and fauna from one band will struggle to survive in another and biomes are typically unique to each band.
Note: the sizes of these cells are not constant across planets - the Hadley cell in Venus can reach up to 60 degrees, whilst Jupiter possibly has multiple Hadley cells.
The rain shadows mentioned above are simply areas on the leeward side of a mountain (facing away from the wind). Mountains block the movement of rain-clouds, allowing only warmer dry air to pass. This is why the Tibetan plateau is so arid - the Himalayas stop rain clouds from moving beyond them. Check your world map, thinking about the Hadley and Ferrel cells and prevailing winds in relation to any mountains to see where regions of rain shadow might be located. Those areas shouldn’t have much rainfall, rivers, or vegetation.
Something else to note is the less ocean your world has the drier the world is going to be - you’re going to have less rain, more continental deserts and overall less vegetation away from windward coastlines.
Winds and currents broadly follow the directions of the Hadley and Ferrel cells, so winds tend to blow to the west towards the equator within the Hadley cell, and to the east in the Ferrel cells. Remember the doldrums around the equator, where winds are relatively weak. Also keep in mind that currents moving towards the equator from the poles will be cold, with the reverse true for currents moving towards the poles from the equator (Gulf Stream)
In some areas prevailing winds are known to reverses direction (monsoon in India), which happen when temperature on land is warmer or cooler than that of the sea and happen in areas where the equator is covered in sea, with a continent along the 30 degrees line.
Koppen Climate Classification
I mentioned tropical, temperate and arctic bands earlier on, which are the simplest way to express climate bands. The Koppen Climate classification, published in 1884 categorizes these in far more detail than I can ever get into in this article. Broadly, there are five categories:
Below is a list of the more common climate classifications and what areas of your world they apply to. Exceptions can and do exist however, due to localized conditions.
Note: that the above is only a rough interpretation of real-world analogies and if you were to create a climate map of your world and show it to two different experts, they would likely disagree as to the exact climate zones to implement. There are so many factors - prevalent winds, currents, mountains, rain shadows etc. that it’s impossible to create an accurate climate map that everyone would agree upon. So do your best and make sure that you have an in-world explanation for blatant abuses of the above - particularly forests in rain shadows: I’m looking at you, Fangorn Forest!
All the above should give you a good foundation for a world map. You should have a general idea of your coastlines, where your mountains are located, where rivers should flow and the generic climate. The specifics can always be fine-tuned later on - you can tweak your coastline, specify the height and span of mountain-chains, pinpoint the course of a river, etc. Such things can be kept for when you need to specify them.
Key things to remember:
Atmospheric Circulation - https://en.wikipedia.org/wiki/Atmospheric_circulation
Climate - https://en.wikipedia.org/wiki/Climate
Endorheic Basin - https://en.wikipedia.org/wiki/Endorheic_basin
Genesis of common ores https://en.wikipedia.org/wiki/Ore_genesis#Genesis_of_common_ores
Koppen Climate Classification - https://en.wikipedia.org/wiki/K%C3%B6ppen_climate_classification
Plate Tectonics - https://en.wikipedia.org/wiki/Plate_tectonics
Rain Shadow - https://en.wikipedia.org/wiki/Rain_shadow
River Basin - https://en.wikipedia.org/wiki/Drainage_basin
River Delta - https://en.wikipedia.org/wiki/River_delta
Trade Winds - https://en.wikipedia.org/wiki/Trade_winds
Trewartha Climate Classification - https://en.wikipedia.org/wiki/Trewartha_climate_classification
Atmosphere of Jupiter - https://en.wikipedia.org/wiki/Atmosphere_of_Jupiter
Hadley Cell venus - https://www.seas.harvard.edu/climate/eli/research/equable/hadley.html
Number of atmospheric cells per planet - http://earthscience.stackexchange.com/questions/992/what-factors-determine-the-number-of-hadley-cells-for-a-planet
One artmospheric cell postulation - http://worldbuilding.stackexchange.com/questions/21838/what-would-the-climate-be-like-on-an-earth-like-planet-with-only-one-convection
Part Two: The Smaller Picture (6th Nov)
Part Three: Civilizations (13th Nov)