World-building 104: The Lay of The Land

Posted on Sunday, September 21st, 2014 at 20:53

Welcome to the latest post in my world-building series.Last time I posted about the Fundamentals of a world, this time I’m going to talk about the thing that most people seem to think is the most important part of world-building…

The frontispiece of 'The Hobbit'

The map that pretty much started it all.

No, not the map…

The world itself. We are going to discuss the Geography of the unreal. Whether we are talking about alien worlds from science-fiction, scary other-realms in horror or the delightfully recognisable worlds common to fantasy, there are forces at play in these places that go beyond the needs of the story, at least if you do it right.

And then I’ll talk about the map.

Worlds and Otherworlds

In order to get through these posts on World-building I have to occasionally define what sort of world I’m talking about. In this particular post I’m concerned with the actual geography of the story/gameworld. This could mean:

  • An actual planet, just like Earth, Mars or Lesneelaf (Garner’s homeworld in the Paradox War trilogy). In general these are big balls of rock, liquid and gases that hang around stellar systems and have physical rules that govern how they behave and what they look like. If you are making a physical world then you won’t want to mess about too much with the Fundamentals, as you can quickly make an unbelievable world by simply forgetting to include friction, pressure, plate tectonics, temperature or those changes you made to gravity, chemistry or the speed of light in your concept of the world.
  • A realm removed from the planet as a whole, which operates much like a pocket universe off the main one. This is quite common in children’s fantasy, where worlds hide in wardrobes, paintings, over rainbows, beyond oceans, down rabbit holes or through mirrors all the time. In these ‘realms’ the normal rules of geography need not apply, and you can muck about a lot more.
  • An underworld or spirit world, that exists alongside or beneath the real world. Quite common in mythology and religion, these realms don’t necessarily obey any rules of physical existence, but do often seem to somehow mirror the real world, in which case you might want to think about the geography as an exaggerated form of the real world, hills become mountains, ponds become lakes, streams become mile wide waterways, etc. Of course some are just firey, sulphurous caverns beneath the ground.
  • Constructs and artificial worlds. These things, be they Dyson spheres, ringworlds, space stations or the Matrix are created by beings (in story characters usually called Architects or Builders for obvious reasons). They generally do obey rules, but they need not be the rules that natural worlds obey. Choices in constructs are often aesthetic rather than natural, but its okay because the architect should have balanced the physical and material engineering needs against the aesthetic choices, so the water doesn’t just flow off the edge or whatever.

Climates, Regions and Biomes

There is nothing in science-fiction that screams unreal like the single biome planet. Whether its a world that is all hot desert, all forest or all ocean, it just seems unlikely to exist, and especially unlikely that life could survive there. Sure, there are great examples that appear to break this rule, the planet Arrakis in Frank Herbert’s Dune seems to be a desert planet where life couldn’t evolve, but the details of the world include hot desert near the equator and cold desert near the poles. The water on Arrakis is locked up by the lifeforms that have evolved on the planet. They did not evolve on a desert world, they made the world a desert.  That makes it believable, where as we get nothing like that sort of complexity in Star Wars, where the planet Tatooine seems to be cooked by two suns and have no water, but still has indigenous life forms (that look like amphibians in at least one case), but only animals as far as we’ve seen.

Thermal map of Earth

Check out how the temperature varies across earth

In fact, the Star Wars universe seems to only have single biome planets (and forest moons), which may mean that in that Galaxy far, far away the Fundamentals were very different, long, long ago, or that George Lucas simply thought about planets as locations, Tatooine is Tunisia (and suspiciously close to Tataouine) with a bit of Death Valley thrown in (in ‘Return’), Hoth is Norway, Endor is the Skywalker Ranch’s backyard, etc.

Real worlds are rarely like this, (alright Venus is, but there is nothing living there, as far as I know) think about Earth for a moment. The average temperature varies quite a lot from equator to poles, and also varies depending on how far from the ocean you are. Just look at the image to the right. You can see a huge variation in temperature that also includes cooler temperatures at higher altitudes and warming ocean currents.

Temperature is very important to a world. Cold air is less energetic, it holds less water and can be very dry. Warm air on the other hand can store more water, but is more energetic and much more likely to form a storm, what’s more the storm will be more powerful the more heat there is available to drive the storm. Temperature directly affects pressure and drives currents in water and in the air, pushing the jetstream around, which has further impacts on climates in a region. Currents in the North Atlantic keep northern Europe warm and wet, but deny North Africa much of the rain that it should have.

On Earth we can break the climate of Earth up into types that occur in certain regions. Across Earth we find certain regions have similar plants and animals, we call these similar ‘communities’ biomes. Earth has five or so biomes, which are generally given as Aquatic (although deep and shallow vary), desert (low rainfall, not necessarily warm), forest (where trees grow, often high rainfall in the case of rainforest), grassland (which has varied rainfall, and includes Prairies, Steppe and farmlands) and Tundra (where its generally cold and rocky), although Swamp/Marsh is sometimes included as well.

Oceans and Continents

Oceans are defined as large bodies of salty water, and are often divided into seas for purely identification purposes, since Earth actually has only one Ocean which is unbroken around all the islands above it. This may not be the case on other planets (and has not always been the case on Earth either), where inland oceans may be possible. On Earth we have inland seas that are separated from the global ocean on some continents, but they are usually classified as saltwater lakes. The land on Earth does do a pretty good job of breaking up the global ocean, so we can point out differences between the Arctic, Atlantic, Indian and Pacific oceans, the separation of North and South on the Oceans is largely for identification purposes as there is little to separate the North Pacific from the South.

Plate tectonics and mountain formation

Thinking about plates can help you locate mountains and volcanoes

Continents are more difficult to classify, they are large bodies of land that rise above the Oceans, but there is debate as to how many Earth actually has with the numbers varying between 4 (America, Afro-Eurasia, (Indo-)Australia, Antarctica), 7 (North America, South America, Africa, Europe, Asia, Australia and Antarctica) and 15 (The tectonic plates – although this number ignores the tertiary plates that the larger plates are made of). I generally think for world-building the actual Tectonic plates are the best way of thinking about the world.

Tectonic plates are lumps of rock floating on a molten core, they move and grind, creating earthquakes and mountain ranges (including volcanoes) and pull apart, creating rift valleys, seas, and more volcanoes. You can do a lot worse when designing a world than start with some simple shapes and then decide which way each one is moving to create some mountain ranges and island chains. It can certainly make for a more realistic world than just randomly drawing some island shapes on a map.

Land Go Up, Land Go Down

When continental plates crash together fold mountains are formed, the speed they rise depends upon the momentum of the plates in collision. Huge plates that are moving quickly raise the highest mountains (I’m looking at you India), but the tallest mountains (Hawaii) are not made this way, instead the lava from a volcano simply piles up into huge stacks.

Fold mountains often lift and expose rocks that formed in ancient seas, or from layers of basalt from ancient lava flows, which can mean they have obvious strata that show the immense forces that bend and spindle the land under our feet. If you want to have fossils, limestone, salt and flints to be far inland then these are usually formed in ocean beds and lifted in fold mountains. The pressures and heat beneath the crust can cause rocks to change and fuse, so you can end up with limestone being compressed and cooked into marble, perhaps one day a mountain range will rise above the current location of the mid-Pacific gyre that will include compressed and cooked plastics in a new form of rock. Pressures in these folding mountains can cause veins of metals to flow into cracks and voids in the rock, especially as many of the ores are also created on the sea floor, through ore genesis processes.

A magic 8 ball says As I See It Yes

Magic 8 ball, if the Earth shrunk to the size of you, is it true the plates would seem to join seamlessly?

It is perhaps worth pointing out that compared to some planets Earth’s current sets of mountains and trenchs are so tiny as to almost be negligible, in fact if you shrank the earth to around the size of a billiard ball (or snooker or pool – lets not be gameist) the Earth would actually turn out smoother than the real ball, and what’s more there probably wouldn’t be enough water on its surface to get your hands wet (but it might leave a damp spot on tissue paper). Mars by comparison would be a smidge bigger on one side and have quite a tiny (nearly 1%) lump where the solar system’s largest volcano Olympus Mons was lurking, which might effect how it rolled, just a little.

Even the slight pear-shape (or oblate spheroid if you prefer) of the planet Earth is pretty negligible when compared to the size of the planet, it comes in as about a third of a percent of the overall. Which I defy anyone to spot on any ball (even the largest beach ball you may find). In short Earth is pretty much a glassy smooth marble, and unless you make bearings for high tech gadgets as approximately spherical as you might like.

Once a mountain range or single volcano has arisen (even the little amount they do on our marble planet) it has a dramatic effect on the climate around it. Volcanoes commonly spread ash, smoke and corrosive gases into the atmosphere, these can have a cooling effect downwind, and often increases rain fall (or snow if its cold enough). Mountain ranges cause winds to pass over the tops of them, which causes a permanent high pressure system with limited rain-fall in front of the mountain and a low-pressure area that is called a rain-shadow in the lee. Most of the worlds tropical rainforests lie in the lee of one or other of the world’s mountain ranges. Including the Amazon basin, which is fed by the Andes, just as South-East Asia is watered by the Himalayas. There are other factors at work here too. High altitudes are usually cold, and moisture at these altitudes falls as snow and hail, which in time can build up into glaciers. Current climate change has placed almost all the glaciers into retreat, which means they are melting, releasing their waters in cascades down the mountains, which also helps feed forest and grasslands across the globe, but there are a few (estimates are between 11 and 1000 world-wide depending on how rigorous your science is) that are still growing, and even these release melt-waters ahead of the glaciers.

Mountains basically are part of the water cycle. they attract moisture and release it from the atmosphere, so that it can return, via rivers and plains to the seas once again. All that water, pouring on the mountains has its effects though. Water dissolves and erodes rocks, breaking those mountains down, creating caves and gorges, huge, sharply-pointed mountains become rounded, hills in time, surrounded by rolling plains of soil and silt. If the mountains are suitably volcanic, or were once part of the right sort of sea, the soils created will be highly fertile, rich in minerals.

Dangerous When Wet

The water cycle

If you want rivers, storms, trees and all manner of useful things, you have to keep the water cycle cycling.

As important as mountains are to the water cycle, water is important to the landscape. Glaciers and rivers carve and erode the land, the seas are constantly nibbling inland too. On Earth we have the essential Hydrological cycle that keeps the rivers running.

Water forms lakes in suitable depressions in the land, and if large enough, and warm enough, the water can evaporate from the lake at the same rate or faster than it fills, which causes the water to turn salty (from dissolved mineral salts) and can form a salt-lake (or inland sea), and in time may form a salt-flat. Salt lakes are quite common on Earth (there have been some enormous ones in the past). Most lakes however are simply a slightly deeper, slightly wider part of a river and empty at the opposite end to where they fill.

Rivers (and their cold cousins glaciers) carry silt down from the mountains across the landscape, they drop the silt in the slow moving parts of the river (like the inside of river bends) and pick more silt when fast-moving (like the outside of a bend) which over time causes the river to change shape and creates a river valley (glaciers tend to be more direct and create steeper sided valleys), it can create oxbow-lakes as curves are cut free from the river entirely. When the river is particularly large and heavily silted it tends to create a river delta at its mouth. River deltas are usually highly fertile areas, and are often amongst the first places that people tend to inhabit.

The actions of waves and tides is constantly gnawing at the base of cliffs around the coastlines of all the continents. In some places the rate of gnawing is fast enough that you can almost watch gardens and houses fall into the sea, but usually on average the coastline is fairly static. Storms and tsunamis may suddenly take a section of a cliff or drag a low lying loose soils and sands out to sea, but the processes of water erosion (from river and sea) are gradual processes that change the outline of an area slowly. Still though when huge bodies of water are released at once they can wreak massive changes to the landscape (the Badlands in Montana seem to have been created in a few hours when a wall of ice collapsed and released Megalitres of water across the North-West of America), also as landscapes alter river valleys and gorges can change how they are used by water. An example may be the Grand Canyon which some geologists believe was carved in the opposite direction to how the Colorado river now flows, as the land has risen in the meantime.

A Living World

There is a big difference between Earth and Mars, some of that is down to the thickness of Earth’s atmosphere and the functioning water cycle, but there are signs that early on Mars had both of these things. The biggest difference is the lack of life. Life smooths the rough edges of the worlds, it accelerates the formation of ocean mud, and rock erosion, as plant roots tear apart the valleys around the rivers, but also slow the after erosion and divert the rivers.

Earth has about as many impact craters as Mars, but top-soil and tree canopies smooth them practically out of existence. This is why on Earth the most famous craters all occur in deserts, where they are easily spotted.


So now you have a broad understanding of how Earth works, and you might even be able to see how that fantasy world you want to build might work. So the next thing to do is draw the map.

Personally, I tend to draw my maps on paper by hand, but there is something to be said for building your map on computer (a vector drawing package as Illustrator or Inkscape can be preferable as vectors print better, but any modern graphics package will work) where you can build in layers, perhaps first drawing the tectonic plates then adding a layer for the continents, with another layer for the rivers and lakes, and another for sea water. You can then even add layers for the cultural aspects, like the most common languages, demographics, cities, roads, railways, economic produce, architectural styles, etc.

A map made in Campaign Cartographer 3

Campaign Cartographer 3 not cheap, but dedicated

There are a number of great Cartographic resources and software for budding world-builders, if you have plenty of money you can get real professional software for map building, and many GMs and DMs like ProFantasy’s software, which is a pretty good option, Fractal Mapper is another example.

If you want to go for a free option, you may be out of luck these days (although doing a search for “free open source fantasy map cartography software” might be a good start) and links to these sorts of resources are rarely stable.

There are a number of good websites and resources that can produce fractal worlds and terrain, which look pretty close to a real world (although they tend to ignore the processes of erosion and can rarely include the effects of life on the planet), and some people seem to like them, but I’ve always thought that they aren’t actually as good as using a good graphics package and perhaps some clip art map symbols.

To map or not to map

So that’s how you do it, but what map should you be drawing? Some authors and GMs have to start with the world-map and that’s fine, but totally unnecessary if you are actually only dealing with a story that is set on a single island or in a single city, in which case those are the maps you really want to get drawn.

I do like to have the world-map available so that I know where everyone in the story is actually from, and where in the world the story is set, but when gaming the players rarely get to see that. Instead the maps they buy/find tend to be a regional map which is just a tiny section of the world, and the location maps tend to be the ones I worry about most (the dungeons and so on in a game) as they are where the characters spend most of their time (so to speak).

Even when you have drawn a map, that doesn’t mean you have to stick it in the book, or show it to your players. It has become a staple of Fantasy literature, and many fans expect a map, but you really only need to include it if it serves the story or the readers’ understanding of the story. Stories that are highly political (with multiple diplomats from various foreign countries), war stories and the like, or are essentially travelogues across the map in question, probably do need to include the map, but if you are just trying to lift a curse from a peasant village, the reader might not need to know where the nearest river is.

Well that’s about it for the physical world. Next time I’ll post about the Eco-systems.