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GameMastery Guide / Creating a World / Geography

Terrain Hierarchy

Source GameMastery Guide pg. 146
When it comes to drawing your map, keep in mind that the world’s shape follows a specific hierarchy. As you draw your map, it’s best to follow the steps below and make your decisions in this order—after all, it’s tough drawing rivers without knowing where the mountains and coastlines are.

Geologic Touchstones

Source GameMastery Guide pg. 147
Below are several handy bits of trivia about the real world that can help with fantasy map design.

Deserts and forests each cover approximately a third of the Earth’s land surface.
Oceans cover approximately 70% of the Earth’s total surface.
The peak of Mount Everest, at 29,028 feet, is the highest point above sea level on Earth. (The tallest mountain on Earth, on the other hand, is Mauna Loa, which from seabed to peak rises 33,500 feet.)
The lowest point in the ocean is the Mariana Trench, at a depth of 35,797 feet.

Coastlines

Source GameMastery Guide pg. 147
The first step is to divide land from water—draw in the region’s coastlines, remembering to add bays and harbors here and there (these make great locations for major cities). Scatter islands, inland seas, and lakes here and there, bearing in mind that a chain of islands extending off a coast might indicate an extension of a mountainous region into an ocean or sea. Unless you’re an expert on geology or cartography, don’t worry about things like plate tectonics or trying to map the curve of the planet, especially if the region you’re mapping is only a single continent or smaller. (Of course, it can’t hurt to freshen up on these topics.) One way to make this easier is to vaguely base the shapes of your continents on the shapes of Earth’s continents, a tactic used by many game designers and fantasy novelists.

Elevations

Source GameMastery Guide pg. 147
Once your coastlines are set, draw in the outlines of where you want your region’s major mountain ranges to run. A mountain range outline should generally be long and narrow, perhaps with multiple “fingers” extending from its length, since mountains often form as continental plates push together to “wrinkle” the surface of a world. Mountain ranges that roughly follow a region’s coastline are common, as seen along the west coasts of North and South America. Volcanic activity can also cause mountains to rise—now’s a good time to place some volcanoes (preferably in a line along a mountainous coastline or a range of mountains). Once you have your mountainous regions placed, you can draw an increasing number of outlines around those mountains to show gradual changes in elevation as you work your way down to the coastline. Don’t be afraid to make these lower regions wide and large—you’ll need somewhere to put your deserts and large forests. Also remember that mountain ranges extending into oceans are an excellent source of realistic island chains.

Rivers

Source GameMastery Guide pg. 147
Once you have the elevations of your region marked, you’ll be able to place rivers. Start near the centerline of a mountain range and wind downward on whatever curving course you want as you approach a coastline. Make sure that your rivers don’t double back across an elevation line once they cross it, since water has a hard time flowing uphill. One important thing to keep in mind is that, as a general rule, water wants to flow together rather than apart—as a result, you should avoid having your rivers “split” as they flow downward from the mountains, save to create a delta like those at the mouths of the Mississippi or the Nile. Likewise, make sure that you don’t have multiple rivers emptying out of a lake!

Vegetation

Source GameMastery Guide pg. 147
Sketch in major woodlands or jungles, placing them along coastlines and in lowlands, perhaps up to the edges of your highest elevations in places. Vegetation near a large water source like a delta often forms a marshland or swamp. Don’t go too overboard with these regions, though! Remember that areas you don’t turn into woodlands or swamps can be hilly regions, plains, steppes, badlands, or other relatively clear terrains. Deserts are a special case—place them in areas where there are few rivers (it’s okay to have one or two) and where there’s a mountain range to block the path of precipitation—this area is known as a “rain shadow.”

Breaking the Rules

Source GameMastery Guide pg. 147
While these guidelines stress the importance of realism, don’t forget that you’re designing a fantasy world! Anything goes—feel free to have rivers flowing uphill, mountains that float on the ocean, deserts or forests that move, or swaths of ocean where the water drops away to expose portions of the sea bed. As long as you realize that these locations are unrealistic, you can design for them and explain them however you wish.

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