Building a Fantasy Campaign World III: Geography

Eventually, when designing a new fantasy campaign world, you’ll want to map things out. For many this is just doodling on paper or in Photoshop or turning to a campaign cartography or fractal mapping program. But let’s look a little deeper at maps and charting your world, to avoid some of the common pitfalls and mistakes.

This is the third chapter on a series on world building.

Table of Contents

This blog is part of a series on Fantasy Worldbuilding. The other parts are listed below

Part 1: The Hook
Part 1.5: Variables
Part 2: Conflict
Part 3: Geography
Part 4: Races
Part 5: Nations
Part 6: Monsters and Dungeons
Part 7: Deities
Part 8: Cities
Part 9: Organizations
Part 10: History
Part 11: Economics
Part 12: Culture
Part 13: Starting Zone
Part 14: Player’s Guide
Part 15: Other Realms
Part 16: Miscellaneous

Continental Basics

Let’s start by jumping ahead to continents. If you’re planning a Bottom-Up campaign this won’t be of much use – but that would make for much shorter and less fun blog series.

There are two major styles of continents that seem to have gained prominence: the partial continent and the ovoid continent.

Partial Continents include worlds such as Greyhawk, Mystara, Forgotten Realms,Tolkien’s Middle Earth, Paizo’s Golarion, and the Wheel of Time’s Randland. Oval continent include Dragonlance (twice), Eberron (4 times), Birthright, Returned Abeir in the Forgotten Realms and technically Ravenloft.

Partial Continents suggests that the map cannot contain the full world at an adequate scale. This is a little like Europe, which is kinda sorta its own continent despite being physically connected to Asia. Given much of fantasy fiction evokes medieval Europe making the map analogous means there can be similar cultures and familiar trade. They offer a nice landmass to explore but suggest there might be more “out there”, beyond the borders of the map. They’re a world with room to expand. It’s not a world (or continent) in a bubble. Plus, since Lord of the Rings did it first it’s kinda a convention.

The ovoid continent is also a big convention of fantasy fiction. Look at a map of the earth. There’s not a lot of oval continents (pretty much just Antartica and Australia, but the latter has all the island chains of Oceana nearby), so it’s breaking farther away from the familiar. Ovoid continents are so ubiquitous due to the conventions of publishing: they fit nicely on a poster map, a landscape page, or a two-page spread. They’re also nicely self-contained, for those who don’t want to worry about players charging right for the unmapped areas to “see what’s out there.”

It’s tempting to just start drawing islands, randomly doodling coastlines and slapping sub-continents and island chains in various places. But often this results in a map akin to Terra from Might & Magic III with a bunch of unrelated landmasses that are just there.

The above works as a world but for the sake of detail and realism let’s look a little deeper.

Understanding Geography

Let me start by saying I am not a geologist and have no formal training in Earth Sciences. So there’ll be some gross oversimplifications at work here.

Continents are composed of one or more tectonic plates and mountains form where plates meet and press together. Regions where plates meet are unstable and prone to earthquakes and volcanoes, as seen in the West Coast or Hawaii. Newer mountains and steep and craggy (like the rocky mountains) but over time the weather erodes and rounds mountains into smoother peaks (like the Appalachians).

When planning a Top-Down campaign world it’s not that much more work to sketch out a few tectonic plates and the direction they’re moving. You don’t need to map out the path of continental drift over the past hundred million years, you just need to know where the stress points are and what plates are pushing together, or pushing apart, or pushing over. Once you know where the plates interact you can draw mountains and island chains.

(As always it’s more complicated than that, as mountains can be around a really, really long time. For example, the Appalachians are in the middle of plate and date back to the supercontinent of Pangaea when northern Africa was squishing against what would become the East Coast of America before the North America plate pushed away and expanded. So if you want more mountains in the wrong place you can add an ancient range.)

Coasts can be tricky. There’s a surprising variety of coastlines, but it’s a good idea to keep them rough and irregular. Within reason. As was noted in Hitchhiker’s Guide to the GalaxyFjords aren’t very equatorial. It’s easy enough to look at a comparable landmass in the real world and add comparable crinkliness to your continent.

Fjords are the result of rivers and erosion from glaciers, which have had an equal impact on North American terrain. I shouldn’t have to say this but I will anyway: rivers flow downhill. They start as small mountain streams and joining other streams to form rivers. Rivers are like reverse trees, starting out as many smaller branches and getting fewer and fewer and larger and larger.

A very common fantasy cartography mistake is to have rivers branch and split: this is pretty damn rare as water is lazy and takes the path of least resistance. If a river is forced to fork one path – the easier one – will become the new route of the river and the other route will dry out and die. Rivers are also seldom straight, and wind and curve following the terrain.

Here’s a couple images from a 3D map. They’re not 100% accurate and the painter made some of the aforementioned goofs with the smaller rivers but it gives you an idea how rivers look. Check out Google maps as well and look at some rivers.

Lakes and ponds are tied to rivers, being fed by rivers (inlets) where the water pools until it essentially overflows from the lake out of an outlet. Lakes typically only have a single outlet, but multiple rivers can feed them.

As an example of how easy it is to make a mistake, here’s a scan from an earlyGreyhawk product showing either a river flowing into the mountains and a lake, or two rivers flowing out of a lake.

Seas are salt water bodies, opposed to lakes that tend to be freshwater. They’re often connected to the ocean through a channel, but they’re often lakes that lack an outlet and have become saline instead of fresh water due to accumulated minerals. Seas are often smaller regions of the ocean that are bordered by land on two or more sides. Inland seas occur in dryer regions, where flowing water isn’t so common that the sea overfills and develops an outlet. In temperate areas there are typically large lakes instead of seas, as regular winter runoffs cycle out the water preventing salt accumulation.

In larger bodies of water (oceans) there are also water currents. These are typically clockwise in northern latitudes and counter-clockwise in southern latitudes. This is important for shipping lanes and knowing if currents and bringing cold or warm water. It’s handy to know but less important on world building.

Jumping back to rivers for a second, I should not that most rain falls on one side of the mountains. Wet air is blown by the wind from the ocean until it hits mountains where the air is pushed up, cools, and becomes rain. So there are more streams and rivers along the wetter side of mountains. So the air after the mountains is drier. While there might be rivers (from mountain streams) there is less rain in the rain shadow. To figure out where that would be I need to talk about how air moves.

Understanding Climate

Geology is hard but climate is harder. Geology is consistent but climate is affected by a vast multitude of small interrelated factors. This is why we cannot predict the weather accurately and why we cannot be exact on the effects of Climate Change from Global Warming on a small regional scale. There was a solid documentary on this on Discovery a while back called Earth from Space if you can track it down.

As such, it’s pretty much impossible to make a fake world entirely realistic. But this also means once you establish the big zones and obvious climatology you can fudge the rest under the guise of dozens of small invisible systems at work.

At its core, climate is governed by the wind. The tropical winds blow one direction (west) while the temperate winds blow another (east).

The air also circulates and flows, being pulled up in an endless cycle.

Notice the gaps between the major wind currents, the zones where the tropics become the temperate zones. These are the horse latitudes which contributes to the arid regions at those locations.

What all this means is that we can divide the globe into three zones: the tropic, the temperate, and the polar with deserts in the high pressure regions where the tropics become temperate.

Understanding Scale

This is more of a pet peeve than a big point for world building. I once offered to purty up some maps for a friend of mine’s fantasy world. He hadn’t really travelled much, maybe five hours drive from our city. And, being a North American used to cars he has a pretty skewed sense of scale (what with our hundreds of kilometres of plains endlessly stretching across the continent). So he tossed out some numbers that seemed impressive, pegging his continent at roughly 8,000 km by 8,000 km. Or, put in prespetive, about the size of one-and-a-half Asias.

It’s also possible to low-ball the scale. Dragonlance is an excellent example with the continent of Ansalon being half the size of Australia. I’ve heard it compared to Western Europe but it’s really more comparable to Spain, France, and Britain with the border between England and Scotland flooded and a big water-filled gap in eastern France where the Blood Sea would be. Which would be fine if it was built around being a small land, but the southern tip of the continent is by icefields while the northern regions are tropical. So the entire planet is tiny.

It’s been said that to an America a hundred years is a long period of history and a hundred miles is a short distance, but to a European a hundred years is a short period of history and a hundred miles is a long distance. World building emphasises this.

Remember that in D&D, the average person can travel somewhere between 30-60 km each day (20-40 miles). If something is more than 80km away (50 miles) it’s a two day trip. For us, that’s a couple hour drive. People commute longer than that.

When designing a fantasy world remember that at its peak, Rome was only 5 million square kilometres, a unwieldy size for the ancient world but around half the size of the United States. While magic can be used to justify faster travel, easier communication and the like transporting food and goods for the common folk will still be a slow arduous process. Work and plan accordingly.

Geography in War World

As I’m building this world for a blog and likely not for use in my homegame anytime soon, I’ll be cheating on my geography a little. Rather than designing a brand new continent from scratch, I’m starting with South America flipped vertically. It’s not the standard oval shape of fantasy contintesm – which is a nice change – but serves a similar function. Being long and narrow lends itself well to this blog site (which tends to narrow pictures).

I’ll also move the continent north a little, so the tip is well within the Antarctic circle. This means more of the continent is in the Temperate zone and closer to the European and North America climate. The Equator moves from Ecuador to the Guatemala area.

I’ll draw on the plates, mimicking the ones in real life. But to simply a little I’ll remove the small Scotia plate. And to add some extra mountains and shake things up, I’ll add a landmass to the Cocos plate and slam that into the southern end of my continent as a subcontinent like India.

I’ll draw some lines onto the map where the plates interact and form mountains. The Andes should be familiar and unchanged, but I’ll add some mountains where I smashed in the subcontinent. I’ll add some small, old mountains in the region that used to be southern Brazil for reasons similar to the Appalachian Mountains. Just to add some diversity to the terrain.

Now onto the climate. Flipping and moving the continent would normally radically change the climate, moving the direction of the prevailing winds. However, because I flipped and moved the continent the winds are roughly in the same position, although the horse latitude shifts down (from what was Southern Brazil to what was Northern Brazil).

What was Southern Argentina becomes dry tundra in the rain shadow of the Andes. The arbitrary mountains I threw into the Southern Brazil region would catch much of the remaining moisture in the clouds creating rain, so there would be a number of streams. The lowlands of Northern Argentina and Paraguay would become rife with rivers. There might be some marshland here as well as temperate to boreal forests.

Bolivia and much of south-central Brazil would likely be temperate forests and plains, possibly resembling the central United States. Peru, being in the horse latitude and a rain shadow would be arid desert. It would be dry well into Brazil before the desert would likely give way to plains with forests near the many large rivers now flowing to Venezuela or Central Brazil. This area might be prone to tornadoes as well, likely funnelled north by the mountains.

Northern Brazil with would be heavy forest and jungle with its many rivers from the double mountains and the wet south-westerly wind dumping rain. Venezuela and Columbia would see some rain and be the focus of rivers channelled down the continent. They’ll likely be more than a little swampy, like hotter and more equatorial Louisianas.

This all sounds complex but doesn’t take that long or nearly as much effort as it looks. It doesn’t take long to draw out the map, figure out the scale, and compare its position (in terms of longitude) to someplace in the real world. They sketch out how the air flows and you have a pretty good idea of what the weather and climate would be like. It took me significantly longer to write (and draw in a presentable manner) than it took to sketch out the terrain and air currents on a piece of scrap paper. It’s a little extra work but it’s nice knowing that players won’t look at the world and go “hey, that river is flowing upstream” or “why is there a forest in the rain shadow of that mountain range?” There’s only so often you can answer “magic” to justify slapping terrain wherever. The point of enchanted forests is that they’re supposed to be special, not a crutch for people unwilling to browse Wikipedia.


A compilation of this on Worldbuilding Blog Series, Jester David’s How-To Guide to Fantasy Worldbuilding, is now available.  The blogs have been updated, edited, and expanded, so the final book features almost two-hundred pages of advice on making your own fantasy world.

 Jester David’s How-To Guide to Fantasy Worldbuilding is available in Print on Demand and electronically. The electronic copy is available on KoboKindle, and DriveThurRPG. The PoD copy is available on Createspace and Amazon.

Learn how to: sculpt a continent, design a nation, plan a city or village, create a Pantheon, and build your world! Designed for use by fantasy tabletop role-playing gamers (especially those using the world’s oldest RPG system) but also useful for novelists, creative types, and people with too much free time.

The original blogs aren’t going anywhere, and will remain available for free on the website indefinitely. But if you want an offline or improved version (or support me spending over a year of my life typing away advice) feel free to purchase a copy and earn my enduring gratitude.