Planets
Source GM Core pg. 139
You'll need to develop some details of your campaign's home world before you begin your campaign. While some games might stay on a single planet, the opportunity for space travel and intergalactic contact means you should also consider the fundamentals of the other important planets in your setting. These worlds can also help inspire your players during character creation, especially if they want to play ancestries that aren't native to your campaign's home world. Don't be afraid to work alongside your players to draw inspiration from their character's backstories when choosing the themes of your planets.
While these guidelines are intended for the creation of your campaign's initial home world, they can be revisited each time your players visit a new planet!
While these guidelines are intended for the creation of your campaign's initial home world, they can be revisited each time your players visit a new planet!
Planetary Basics
Source GM Core pg. 139
When designing the physical features of a campaign world, you'll want to determine its shape and the general distribution of landmasses. You should also establish the world's size relative to its neighbors, though the importance of a planet is rarely relative to its mass.
Shape
Source GM Core pg. 139
In a science-fantasy setting, the shape of your world need not be spherical as governed by the laws of physics. It could take on any shape you desire, and it might 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. A vast civilization might inhabit the interior of the world, lining the outer edge with solar panels for renewable power. Light might emanate from a sunlike orb in the world's center, from various other natural, technological, 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 need to decide how gravity, atmosphere, and other details function. These types of irregular shapes can also include asteroids, colony ships, and space stations.
String: The world might be something entirely unique, like a stellar waterway akin to the River Betweena chain of stellar debris each a mini-world in its own right, or even a planetary ring detached from its maiden world and cast into the void.
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. A vast civilization might inhabit the interior of the world, lining the outer edge with solar panels for renewable power. Light might emanate from a sunlike orb in the world's center, from various other natural, technological, 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 need to decide how gravity, atmosphere, and other details function. These types of irregular shapes can also include asteroids, colony ships, and space stations.
String: The world might be something entirely unique, like a stellar waterway akin to the River Betweena chain of stellar debris each a mini-world in its own right, or even a planetary ring detached from its maiden world and cast into the void.
Composition
Source GM Core pg. 140
While most habitable home worlds are assumed to be terrestrial planets like Earth, in a science-fantasy setting the only limits are your imagination, and each change presents new options for far-reaching cultural and technological innovations. Some worlds combine these compositions, such as the tidally locked world of Verces that's half frozen from a lack of sun and half searing from intense solar activity, with a ring of cities separating the two extremes.
Barren World: These barren worlds include asteroids and desert and rocky planets unable to support life on its surface. Residents are often from other worlds or spend most of their lives struggling to survive. Some of these worlds have evolved intelligent life capable of handling the extreme circumstances. They include worlds that once teemed with life that has since been destroyed by war or some other invasive force, like the husk worlds left behind by the Swarm or the once-living planet of Eox. In many cases, the composition of the world is completely bizarre, such as a world composed entirely of crystals!
City World: Also known as an ecumenopolis, this planet-sized city completely covers the surface of the world, often spanning even the vast and often polluted oceans that once supported life on the overly developed world. These planets likely have several superstructures visible from space but are otherwise vast monuments littered with lights. It could've been built on a moon or asteroid, perhaps as a colony from another nearby world. While these worlds are often the most populated, they also frequently have the least variety of life (at least in terms of plants and animals) and could even be mostly abandoned due to a planetwide catastrophe exacerbated by its sprawling monoculture. A city world is likely to be or have once been united under a single nation-state, even if it's now divided into multiple city-states or rival districts. Oftentimes, the planet forms slums near the surface while the wealthy live atop skyscrapers or in floating arcologies high up in the atmosphere where they're safe from pollution and noise.
Constructed: Constructed worlds didn't form naturally but were built by their inhabitants using natural or synthetic materials. A constructed world could be an inhabitable space station, a massive worldship, or a terraformed satellite resembling a real planet. Examples in the Pact worlds include Absalom Station and the Idari.
Gas Giant: These enormous worlds are often circled by countless moons large enough to support entire campaigns. Some, like Bretheda, have cities floating atop or within the gas. Others float along the ring of these worlds, the composition of which can hint at the world's history. Perhaps some creatures can survive on the surface of these worlds, protected by eternal storms too violent for most spaceships to navigate. The substances of these worlds are often harvested for interplanetary trade.
Ice World: Ice and snow cover these frigid worlds often found on the fringes of a star system. Cities frequently develop inside of mountains or atop enormous thermokarsts, regions replete with hollows like the Ice Wells of Aballon, that offer a reprieve from the eternal cold. Perhaps the only known structure in these worlds is a single research or military station operated by a skeleton crew, or perhaps the residents thrive in the frigid wastes or live in aquatic cities submerged under the miles-thick ice.
Lava World: Volcanic plumes of lava and smoke cover these worlds, often controlled by one or more mining companies looking to exploit the rare starmetals and other resources left undisturbed on these often lifeless planets. What kind of life could develop in these worlds? How might they react to being exploited by alien miners? And what valuable resources and treasures might await those who can survive in such a hostile environment?
Lush World: Forests, jungles, or swamps cover these worlds. Whether natural, supernatural, or the result of terraforming gone awry, these worlds often have civilizationending threats, like colossi, that prevent their unspoiled nature from being exploited and their surfaces from rampant development. Perhaps these threats might not be as obvious as giant monsters and could very well be surges of primal magic, random boiling geysers the size of cities that sustain the verdant paradise, or microbial threats that can bypass even the highest-grade environmental protections.
Terrestrial: These Earth-like worlds include oceans and continents with all the variety you'd expect on a habitable surface. The planet itself could've been terraformed with technology or magic necessary to keep it from becoming another type of world.
Water World: A world composed of or submerged in planet-spanning oceans could include a smattering of islands or floating settlements. Is the world surrounded by pristine blue seas, or is the water green due to continentsized algal blooms? Perhaps the liquid isn't even water but instead a substance that either makes the planet a center of the galactic economy, or it's a cursed world avoided and shunned by the rest of the galaxy.
Barren World: These barren worlds include asteroids and desert and rocky planets unable to support life on its surface. Residents are often from other worlds or spend most of their lives struggling to survive. Some of these worlds have evolved intelligent life capable of handling the extreme circumstances. They include worlds that once teemed with life that has since been destroyed by war or some other invasive force, like the husk worlds left behind by the Swarm or the once-living planet of Eox. In many cases, the composition of the world is completely bizarre, such as a world composed entirely of crystals!
City World: Also known as an ecumenopolis, this planet-sized city completely covers the surface of the world, often spanning even the vast and often polluted oceans that once supported life on the overly developed world. These planets likely have several superstructures visible from space but are otherwise vast monuments littered with lights. It could've been built on a moon or asteroid, perhaps as a colony from another nearby world. While these worlds are often the most populated, they also frequently have the least variety of life (at least in terms of plants and animals) and could even be mostly abandoned due to a planetwide catastrophe exacerbated by its sprawling monoculture. A city world is likely to be or have once been united under a single nation-state, even if it's now divided into multiple city-states or rival districts. Oftentimes, the planet forms slums near the surface while the wealthy live atop skyscrapers or in floating arcologies high up in the atmosphere where they're safe from pollution and noise.
Constructed: Constructed worlds didn't form naturally but were built by their inhabitants using natural or synthetic materials. A constructed world could be an inhabitable space station, a massive worldship, or a terraformed satellite resembling a real planet. Examples in the Pact worlds include Absalom Station and the Idari.
Gas Giant: These enormous worlds are often circled by countless moons large enough to support entire campaigns. Some, like Bretheda, have cities floating atop or within the gas. Others float along the ring of these worlds, the composition of which can hint at the world's history. Perhaps some creatures can survive on the surface of these worlds, protected by eternal storms too violent for most spaceships to navigate. The substances of these worlds are often harvested for interplanetary trade.
Ice World: Ice and snow cover these frigid worlds often found on the fringes of a star system. Cities frequently develop inside of mountains or atop enormous thermokarsts, regions replete with hollows like the Ice Wells of Aballon, that offer a reprieve from the eternal cold. Perhaps the only known structure in these worlds is a single research or military station operated by a skeleton crew, or perhaps the residents thrive in the frigid wastes or live in aquatic cities submerged under the miles-thick ice.
Lava World: Volcanic plumes of lava and smoke cover these worlds, often controlled by one or more mining companies looking to exploit the rare starmetals and other resources left undisturbed on these often lifeless planets. What kind of life could develop in these worlds? How might they react to being exploited by alien miners? And what valuable resources and treasures might await those who can survive in such a hostile environment?
Lush World: Forests, jungles, or swamps cover these worlds. Whether natural, supernatural, or the result of terraforming gone awry, these worlds often have civilizationending threats, like colossi, that prevent their unspoiled nature from being exploited and their surfaces from rampant development. Perhaps these threats might not be as obvious as giant monsters and could very well be surges of primal magic, random boiling geysers the size of cities that sustain the verdant paradise, or microbial threats that can bypass even the highest-grade environmental protections.
Terrestrial: These Earth-like worlds include oceans and continents with all the variety you'd expect on a habitable surface. The planet itself could've been terraformed with technology or magic necessary to keep it from becoming another type of world.
Water World: A world composed of or submerged in planet-spanning oceans could include a smattering of islands or floating settlements. Is the world surrounded by pristine blue seas, or is the water green due to continentsized algal blooms? Perhaps the liquid isn't even water but instead a substance that either makes the planet a center of the galactic economy, or it's a cursed world avoided and shunned by the rest of the galaxy.
Landmass
Source GM Core pg. 141
The next major step in world creation is to sketch out the planet's oceans and major landmasses—assuming the world type has them! On Earth, these geological features are the result of plate tectonics. In a science-fantasy world, however, the continents might have been cleaved from the land in a duel between gods or powerful witchwarpers, or the oceans filled by towering terraforming columns that still dot the shores to this day. The following are some common landmass types.
Archipelago: A stretch of vast ocean, dotted by chains of small island groups, atolls, and islets.
Continent: A substantial landform that (usually) rests on a tectonic plate and gradually shifts in position over geologic timescales.
Floating Continent: Whether floating in a gas giant at the point where the composition of the gas becomes semi-solid or suspended by technology or magic above a wartorn world, these enormous landmasses provide a way for traditional life to exist on a planet otherwise hostile to life.
Island-Continent: An enormous island nearly the size of a continent, surrounded by ocean.
Major Islands: A region of seas dominated by large islands, each several hundred miles across.
Orbital: Natural or constructed satellites can be large enough to be settled by intelligent life, perhaps even seeding the ring of a much larger planet or forming a chain of moons.
Supercontinent: An assembly of the world's continental blocks into a single immense landmass.
Archipelago: A stretch of vast ocean, dotted by chains of small island groups, atolls, and islets.
Continent: A substantial landform that (usually) rests on a tectonic plate and gradually shifts in position over geologic timescales.
Floating Continent: Whether floating in a gas giant at the point where the composition of the gas becomes semi-solid or suspended by technology or magic above a wartorn world, these enormous landmasses provide a way for traditional life to exist on a planet otherwise hostile to life.
Island-Continent: An enormous island nearly the size of a continent, surrounded by ocean.
Major Islands: A region of seas dominated by large islands, each several hundred miles across.
Orbital: Natural or constructed satellites can be large enough to be settled by intelligent life, perhaps even seeding the ring of a much larger planet or forming a chain of moons.
Supercontinent: An assembly of the world's continental blocks into a single immense landmass.
Environment
Source GM Core pg. 141
The environment and terrain of a region can pose as much of a challenge to an adventuring party as any of the foes they face. The following section references the environment categories beginning under Environment.
Common Environments
Source GM Core pg. 141
The following environments are common enough that they might appear in nearly any adventure or world.
Aquatic: Oceans, seas, lakes, and other large waterways are aquatic environments.
Arctic: Arctic environments usually appear near the northern and southern extremes of a world, though extreme elevation, unusually shaped worlds, and supernatural forces could result in arctic terrain elsewhere.
Desert: Deserts can appear anywhere on a world where precipitation is scant, even along some oceans. Any large landmasses that entirely lack bodies of water are likely to be deserts.
Forest: The composition of a forest depends on the climate and the elevation, with thick jungles more common near an equator, hardwood forests in more temperate zones, and evergreens at higher latitudes and elevations. Most worlds have a tree line—an elevation above which trees can't grow.
Mountain: A world's highest peaks can stretch tens of thousands of feet above sea level. This category also includes hills, which are typically no more than 1,000 feet tall.
Plains: Mostly flat and unobstructed, plains are usually at lower elevations, but they can also be found at higher elevations on plateaus.
Swamp: Wide floodplains, shallow lakes, and marshes can appear at most latitudes.
Underground: Colonies and outposts on barren worlds are often built underground to protect from cosmic radiation and maintain livable temperatures. They can also be constructed into mountains as part of a larger settlement.
Urban: Cities and settlements are urban environments. These areas are detailed in Settlements.
Aquatic: Oceans, seas, lakes, and other large waterways are aquatic environments.
Arctic: Arctic environments usually appear near the northern and southern extremes of a world, though extreme elevation, unusually shaped worlds, and supernatural forces could result in arctic terrain elsewhere.
Desert: Deserts can appear anywhere on a world where precipitation is scant, even along some oceans. Any large landmasses that entirely lack bodies of water are likely to be deserts.
Forest: The composition of a forest depends on the climate and the elevation, with thick jungles more common near an equator, hardwood forests in more temperate zones, and evergreens at higher latitudes and elevations. Most worlds have a tree line—an elevation above which trees can't grow.
Mountain: A world's highest peaks can stretch tens of thousands of feet above sea level. This category also includes hills, which are typically no more than 1,000 feet tall.
Plains: Mostly flat and unobstructed, plains are usually at lower elevations, but they can also be found at higher elevations on plateaus.
Swamp: Wide floodplains, shallow lakes, and marshes can appear at most latitudes.
Underground: Colonies and outposts on barren worlds are often built underground to protect from cosmic radiation and maintain livable temperatures. They can also be constructed into mountains as part of a larger settlement.
Urban: Cities and settlements are urban environments. These areas are detailed in Settlements.
Extreme Environments
Source GM Core pg. 141
Some adventures lead to fantastic reaches of the world or the multiverse that are seldom explored by mortals.
Aerial: A world might include windy realms of floating islands and castles in the clouds, or form a swirling gas giant.
Alien: Encompassing all manner of unique environments, alien environments represent biomes prevalent to a specific world or even those we haven't yet pondered could exist. Examples could include a vast sea of self-replicating crystal or a world where the landmasses and water shift into different states of matter at irregular intervals.
Glacier: Massive sheets of dense ice constantly moving under their own immense weight, glaciers are frozen wastelands riddled with columns of jagged ice and snowcovered crevasses.
Gravity: Both high- and low-gravity environments present opportunities for fantastical ecologies and challenges for visitors. See page 98 for more details on these environments.
Radioactive: Whether barren wastes or abandoned cities, these environments frequently feature mutated flora and fauna, pools of acid, and radioactive materials that can overwhelm even higher-level environmental protections.
Underground: Some worlds have deep natural caverns, while others have extensive winding tunnels and expansive realms below the surface.
Undersea: A subset of aquatic environments, undersea environments are those areas submerged beneath the waves.
Vacuum: Worlds without breathable air are either deserted wastelands or otherwise occupied only by constructs,undead, and cosmic beings often too alien for most mortals to understand.
Virtual Reality: Your world is entirely digital. Your players can only ascertain this truth over time via hints, and whether or not the entire planet's population is trapped in a virtual space, or the entire universe is a simulation, can depend on the campaign's scope and theme.
Volcanic: Hellish landscapes of molten lava, burning ash, and scorching temperatures pose immediate danger.
Aerial: A world might include windy realms of floating islands and castles in the clouds, or form a swirling gas giant.
Alien: Encompassing all manner of unique environments, alien environments represent biomes prevalent to a specific world or even those we haven't yet pondered could exist. Examples could include a vast sea of self-replicating crystal or a world where the landmasses and water shift into different states of matter at irregular intervals.
Glacier: Massive sheets of dense ice constantly moving under their own immense weight, glaciers are frozen wastelands riddled with columns of jagged ice and snowcovered crevasses.
Gravity: Both high- and low-gravity environments present opportunities for fantastical ecologies and challenges for visitors. See page 98 for more details on these environments.
Radioactive: Whether barren wastes or abandoned cities, these environments frequently feature mutated flora and fauna, pools of acid, and radioactive materials that can overwhelm even higher-level environmental protections.
Underground: Some worlds have deep natural caverns, while others have extensive winding tunnels and expansive realms below the surface.
Undersea: A subset of aquatic environments, undersea environments are those areas submerged beneath the waves.
Vacuum: Worlds without breathable air are either deserted wastelands or otherwise occupied only by constructs,undead, and cosmic beings often too alien for most mortals to understand.
Virtual Reality: Your world is entirely digital. Your players can only ascertain this truth over time via hints, and whether or not the entire planet's population is trapped in a virtual space, or the entire universe is a simulation, can depend on the campaign's scope and theme.
Volcanic: Hellish landscapes of molten lava, burning ash, and scorching temperatures pose immediate danger.
Mapping a World
Source GM Core pg. 142
Many Game Masters like to have an overland map for their local region, nation, or even the whole world. This is far less important if you're planning a multi-planetary campaign with no set home world, but it can help add to a campaign's verisimilitude to include some of these details if your campaign uses a consistent port of call, whether it's a space station or an entire planet. The primary goal of this scale of map is to designate sites of import to the campaign; you don't need to detail every nature preserve or strip mine, but having a sense of the major features can help you and the other players visualize the world in which you're playing.
Step 1. Coastlines: The easiest first step is to separate land from sea (whether those seas are frozen, molten, or even sand). Regional maps might only have a single shoreline, if any. At larger map scales, consider the placement of major islands, archipelago chains, atolls, and islets. A world map should consider the size and placement of continents.
Step 2. Topography: Pencil in a rough ridgeline for each mountain range in the region. Mountain ranges are common along coastlines where continental plates push together. If extended into the sea, mountain ranges typically result in a chain of offshore islands. Indicate hills in the regions adjacent to the mountains and elsewhere as necessary to demonstrate elevation. Unmarked terrain on an overland map is usually lowland plains. Even in worlds with efficient mass transit, these important geographic elements determine defensible positions, population centers, and ports of call.
Step 3. Watercourses: It's important to keep in mind that rivers flow downstream, from high elevation toward the sea, always taking the path of least resistance. Powerful watercourses might carve canyons or gorges over millennia, but they should never cross through mountain ranges. On a similar note, watercourses don't branch—tributaries join into rivers as they flow downstream. Even high-tech societies will naturally benefit from developing alongside natural sources of fresh water, both for conventional uses like drinking and sanitation and for industrial uses like shipping and hydroelectricity.
Step 4. Terrain and Environment: Sketch in interesting terrain features such as forests, deserts, or tundras. You might want to differentiate these by climate, separating coniferous and deciduous forests from tropical jungles or arctic taigas. Terrain not specifically called out on an overland map is typically presumed to be some variety of farmland in developed worlds and grassland in less developed worlds.
Step 5. Civilization: Now you're ready to place the elements of civilization. Major cities are typically located near water, and those with spaceports are usually near the equator to save on the energy required during space launches. Major freeways or rails connect larger settlements, circumventing difficult terrain and connecting centers of culture and industry, but they can wind through mountain passes or even beneath the ocean when lucrative commerce demands it. Add smaller settlements along your roads, like resorts to appreciate nature, less tech-inclined rural communities, or businesses requiring large tracts of land like farms. Finally, draw political boundaries and mark other sites of interest. Are these borders purely physical, or are there separated infospheres on these worlds that further divide these rival nations?
Step 1. Coastlines: The easiest first step is to separate land from sea (whether those seas are frozen, molten, or even sand). Regional maps might only have a single shoreline, if any. At larger map scales, consider the placement of major islands, archipelago chains, atolls, and islets. A world map should consider the size and placement of continents.
Step 2. Topography: Pencil in a rough ridgeline for each mountain range in the region. Mountain ranges are common along coastlines where continental plates push together. If extended into the sea, mountain ranges typically result in a chain of offshore islands. Indicate hills in the regions adjacent to the mountains and elsewhere as necessary to demonstrate elevation. Unmarked terrain on an overland map is usually lowland plains. Even in worlds with efficient mass transit, these important geographic elements determine defensible positions, population centers, and ports of call.
Step 3. Watercourses: It's important to keep in mind that rivers flow downstream, from high elevation toward the sea, always taking the path of least resistance. Powerful watercourses might carve canyons or gorges over millennia, but they should never cross through mountain ranges. On a similar note, watercourses don't branch—tributaries join into rivers as they flow downstream. Even high-tech societies will naturally benefit from developing alongside natural sources of fresh water, both for conventional uses like drinking and sanitation and for industrial uses like shipping and hydroelectricity.
Step 4. Terrain and Environment: Sketch in interesting terrain features such as forests, deserts, or tundras. You might want to differentiate these by climate, separating coniferous and deciduous forests from tropical jungles or arctic taigas. Terrain not specifically called out on an overland map is typically presumed to be some variety of farmland in developed worlds and grassland in less developed worlds.
Step 5. Civilization: Now you're ready to place the elements of civilization. Major cities are typically located near water, and those with spaceports are usually near the equator to save on the energy required during space launches. Major freeways or rails connect larger settlements, circumventing difficult terrain and connecting centers of culture and industry, but they can wind through mountain passes or even beneath the ocean when lucrative commerce demands it. Add smaller settlements along your roads, like resorts to appreciate nature, less tech-inclined rural communities, or businesses requiring large tracts of land like farms. Finally, draw political boundaries and mark other sites of interest. Are these borders purely physical, or are there separated infospheres on these worlds that further divide these rival nations?