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Chapter 2: Tools / Building Worlds / The World

Planetary Basics

Source Gamemastery Guide pg. 122
When designing the physical features of a campaign world, you’ll want to determine its shape and the general distribution of landmasses. You can also establish the world’s size, though note the scale of a world generally has a fairly small impact on the adventures taking place there.


Source Gamemastery Guide pg. 122
In a fantasy setting, the shape of your world need not be spherical as governed by the laws of physics. It could be any shape you desire, and it need not be a planet at all!

Globe: Barring some catastrophe, worlds in our reality are roughly spherical due to the influence of gravity.

Hollow World: What if the landmasses and civilizations of a world existed on the inner surface of a hollow sphere? In such a world, the horizon would climb upwards, permitting creatures to see landmarks at extraordinary distances. Light might emanate from a sun‑like orb in the world’s center, from various other natural or magical sources, or not at all.

Irregular: What if your world is flat, a toroid, or shaped into a cylinder, cube, or other polyhedron? What if it’s something even stranger? With such an unusual shape, you may need to decide how gravity, atmosphere, and other details function.


Source Gamemastery Guide pg. 123
The next major step in world creation is to sketch out the planet’s oceans and major landmasses. On Earth, these geological features are the result of plate tectonics. In a fantasy world, however, the oceans might have been cleaved from the land by the actions of titans, or the continents shaped to suit a god’s whims. The following are some common landmass types.

Archipelago: A stretch of vast ocean, dotted by chains of small island groups, atolls, and islets.

Major Islands: A region of seas dominated by large islands, each several hundred miles across.

Island‑Continent: An enormous island nearly the size of a continent, surrounded by ocean.

Continent: A substantial landform that (usually) rests on a tectonic plate and gradually shifts in position over geologic timescales.

Supercontinent: An assembly of the world’s continental blocks into a single immense landmass.