I like randomly generated things. They introduce a fun element of chaos when I find myself falling into a creative rut. Sometimes I like small random things like NPCs or plot hooks, but sometimes I want something big. Something world-wide. The following rules can be used to define a setting as part of a larger world, or they can be used to generate and entire world.

The below rules are presented as a combination of world generation rules and ideas from games such Traveler, Dark Heresy, Dwarf Fortress, Spore, Stars Without Number, and from online sources like /r/WorldBuilding. I will continue to expand on this article as I discover or concoct new ideas to add.

Stellar Cosmology

A world is defined as much by the space around it as it is by its surface. Earth’s geography, climate, and society are significantly affected by the fact that the Earth has one sun and one moon. Tamriel, the world of The Elder Scrolls game franchise, has a moon, but the sun and stars are actually holes in the native plane caused by the departure of a demonic deity and his followers tearing holes in the border of the plane. Tatooine, the iconic desert world of Star Wars, has two suns but no moon. Eberron has a twelve small moons, but also has a ring made up of magical crystals which occasionally rain upon the world below, and are used for all sorts of religious, magical, and decorative purposes.

Solar Bodies

In the real world, planets revolve around suns. A planet large enough to be orbited by a star is physically impossible. But in your world, all bets are off. The sun may not be a sun at all; it might actually be a divine being flying around the earth on a chariot drawn by winged horses (looking at you there, Helios), or it may be the eye of some huge cosmic being gazing down upon the world below. Or, it might be completely mundane and the people of the world might lack the capacity to understand the mechanics of such a cosmic body, and invent some far-fetched myth to explain it.

1Single SunNice and simple. The single yellow sun is (hopefully) a familiar sight to you and your players. If it’s not, maybe it’s time to get off of the internet for a few hours.
2Binary StarTwo stars orbit around their common center of gravity or a very small star orbits close to a very large star. Depending on the size of these stars, they might be more or less intense than a single sun-like star. If you really want to turn things up to 11, add a bunch of stars all spinning around in a circle at the center of your solar system. It’s interesting to note that binary star systems are more common than single-star systems, but planets in these systems may be less common (Source).
3Super-bright SunThe planet’s sun is either too large or too close compared to the Earth’s sun. The planet will be abnormally warm, liquid water will be hard to find on the planet’s surface, and much of the planet’ surface will be arid desert. Inhabitants might live partially or entirely below the planet’s harsh surface, or they might dwell in the relatively cool polar regions.
4Dim SunThe planet’s sun is either too small or too far away compared to the Earth’s sun. The planet will be abnormally cold. The planet might be covered in glaciers, and will likely have enormous polar ice caps.
5No StarYour planet has no central solar body. Maybe it had one at one point in the past, and the planet broke free from its orbit. Your planet might have a replacement sun, like a huge orbital mirror reflecting concentrated starlight, or your planet might live in perpetual night. Note that the sun provides heat to a planet, and is generally required for life to persist in the cold vacuum of space. Be sure to consider the implications of the lack of a sun.
6UnexplainableDespite a lack of a single identifiable solar body, the planet has a normal day/night cycle. Perhaps a nearby nebula provides enough light, or perhaps some mystical force provides unexplained ambient light.
1MundaneIt’s a giant ball of burning gas.
2Divine/MagicalSome mythical being either is the sun or they control it in some fashion. Perhaps a wizard opened portal to the plan of fire, or perhaps some great glowing beast is bound in the sky by some other magic. Their purpose might be benevolent, or they might just be slowly attempting to cook the planet for dinner.
3TechnologicalSome sort of technological marvel controls or creates the planet’s solar body. It might be a giant gravity ray holding a nearby star in range to warm the planet, or it might be a giant mirror reflecting concentrated starlight.

Lunar Bodies

Moons have considerable effects on the world they orbit. The moon’s gravitational pull affects the Earth’s tides, and the light provided by the moon has plenty of effects which are beyond my limited capacity to explain.

1-2One MoonOne moon orbits the planet.
3No MoonNo major body orbits the planet. Due to the lack of a nearby source of gravity, the planet’s surface might be flatter than the Earth, and tidal patters will be considerably less noticeable.
4Many MoonsDepending on the size and orbit of the moons, their effects can be numerous and varied. You might choose instead to treat the multiple moons like one big moon for simplicity. The moons might orbit in a tight pattern or they might dance across the sky as their fields of gravity pull each other through the planet’s orbit.
5Big MoonThe moon is either abnormally large or abnormally close to the planet. The increased gravity creates violent tidal shifts, and might cause the planet’s geological features to be abnormally tall or short. Sea-side cliffs and huge tidal zones take the place of the Earth’s sandy beaches.
6Tiny MoonThe moon is so small or distant that it has no noticeable effect on the planet below. It’s there, but it’s really nothing to worry about.

Stars and Other Distant Astral Bodies

The stars visible in the Earth’s night sky have held divine, philosophical, and scientific significance for as long as man has gazed at the stars. Every society has some sort of idea about the significance of the lights in the night sky, just as they have some belief about the sun and moon.

1StarsThe sky features an Earth-like mass of stars.
2No StarsThe night sky is black and lightless unless there is a local body to provide light, such as a moon or a planetary ring.
3Dense NebulaThe nebula containing the planet is dense enough that it is visible in the the night sky. The night sky takes on the predominant color of the nevbla, interspersed with stars.
4Shooting StarsThe sky is largely dark, but a shooting star occasionally lights up the atmosphere for a few moments. These shooting stars may be infrequent, or the planet might endure a constant storm of small meteors which are only visible in the darkness of the night sky.
6Roll TwiceRoll again on this table, and combine the results unless they conflict. Ignore any further rolls of 6 on this table.

Wild Cards

Is your planet’s place among the stars still not unique enough for you? Throw in a wild card or two.

1d6 Description
1Tidally LockedThe planet is tidally locked to its solar body. Much like one side of the Earth’s moon always faces the Earth, the planet always faces its solar body on one side. This creates a “day side” and a “night side” of the planet, with a twilight band somewhere in the middle. The planet’s occupants might have no concept of night and day, and likely occupy the planet’s twilight band almost exclusively. The planet’s day side is a roughly circular desert largely devoid of water and life. The planet’s night side is a roughly circular section covering at least half of the planet’s surface, and is a perpetually dark tundra. The twilight band experiences perpetual winds as the hot air expands into the cold air.
2Center of the CosmosThe planet is at the center of the cosmos. Suns, moons, and stars all orbit the planet, which stands still in space relative to the movements of the stellar bodies around it. While this might have only subtle effects on the planet’s inhabitants on a day-to-day basic, it may have major implications for the society and religion of the planet’s inhabitants.
3Planetary BeltThe planet is orbited by a belt of some solid substance such as rocks, crystals, ice, or debris. If the belt is relatively new, it may be stretched around the planet vertically, but over time the rotation of the planet will pull the belt into a roughly flat disk with roughly even distribution.
4Sister PlanetThe planet has a sister planet which is, at least occasionally, visible from the primary planet. The sister planet migh be an exact copy of the primary planet, it might be a wholly unique planet, or it might be a copy of the planet from another dimension. The planet might be reachable by magic or technology, or it might be distant mystery that perplexes the residents of both worlds.
5Orbits something uniqueThe forest moon of Endor was a habitable world in its own right with a lush ecosystem and at least on sentient species. Your planet might be much the same, but hopefully with a more diverse and logical ecosystem. The body which the planet orbits might be another planet, potentially even a habitable planet with its own inhabitants, or it might be a huge dead rock. The presence of this large body might have major effects on the climate of the planet, especially with the possibility of eclipses.
6Significant EclipseSome other stellar body causes a Solar Eclipse which is major enough to have a significant effect on the planet.

Planetary Geography

Generating an entire world is difficult. The complex mechanisms which make up an entire planet are enough to warrant their own article. For a world to look and feel realistic, you must consider millions of years of tectonic movement, geological and astronomical events, potentially magical or divine intervention, and intervention by the world’s inhabitants.

Wild Cards

In addition to normal naturally-occurring features, there may be events or structures so large in scale that they have permanent effects on the shape of the world.

1Ring WorldA classic staple of science-fiction, a ring world is a giant floating ring with a habitable surface on its inner side. The rotation of the ring simulates both gravity and a day/night cycle as the ring brings other cosmic bodies in and out of view.
2Water WorldThe planet is almost entirely covered in water. This might be the normal state of the world, or it might be a result of the actions of the inhabitants. If you don’t want your inhabitants to live underwater, be sure to consider how they survive on the surface, and how they might craft boats, and from what materials.
3Ancient ArchitectureThe planet features ancient structures which dominate huge portions of the planet’s landscape. These structures might be the remains of long dead civilizations, they might be alien in nature, or they might be standing reminders of the past glories of the planet’s inhabitants. Note that this differs from “Artificial World” in that the planet itself is still largely natural, though it may have been considerably modified by its residents.
4World WoundSome cataclysmic event wholly ruined a huge portion of the planet’s surface. Perhaps a huge portion of the planet is a crater caused by some enormous comet, or a string of volcanoes has turned huge portions of the planet into inaccessible fields of ash and obsidian.
5Artificial PlanetThe planet is not a natural planet, and the marks of the planets creators can be seen wherever you look. The planet may have once been a natural world terraformed by some ancient alien race, it might be a giant vessel too large for its inhabitants to comprehend, or it might be a giant structure of some sort floating among the cosmos. Heck, it might be giant planet-devouring robot or an enormous organism, potentially as ignorant to the inhabitants on its surface as humans are to the germs on their skin.
6City WorldThe whole of the planet’s surface is covered by artificial structures. When space ran out, the planet’s residence built upward, turning the planet into an onion-like sphere of overlapping structural layers.



1LawfulSociety is orderly. The land is marked by roads and orderly cities. Government is strong and well established. The word of law is taken seriously, and breaking the law is a serious issue. The wild places of the world are viewed as a problem to be solved. Government might be organized into a strict hierarchy, or it might be otherwise clearly defined. The world has been wholly tamed. The wildest places you might find are city streets or carefully tended parks or nature preserves.
2Leaning LawfulSociety is orderly to a point. There might be a strong centralized government, but places far from centers of power might be disorganized or even lawless. Central organizations might be somewhat hands-off, or they might lack the authority or resources to maintain strict order. The majority of the world is occupied by civilized people, but parts of the world are still undeveloped, though unexplored areas are hard to find.
3-4NeutralParts of society are organized, while other parts are not. Government might be made up of subservient city-states, communities might be “lead” but not actually ruled, or a centralized authority might lack the resources to enforce its will, leaving ineffective or apathetic local representatives to enforce or ignore the law as they see fit.Civilized rea like cities are fairly easy to find, but there may be large undeveloped area between sites of civilization.
5Leaning ChaoticSociety is generally disorganized. There is no centralize authority. The largest governments might be independent societies with no official ties to other societies around them. Independent City states might be the largest organizations around. Nomadic societies may be common. Civilized areas are few and far between. Cities might be in ruins, or they may have never been built.
6ChaoticThere is no “society”. The biggest organization might be a tribe or clan, and permanent settlements might be a rare exception. The concept of rulership might be entirely foreign to the society, and leadership might be based purely on the respect and willingness of one’s followers. There are essentially no civilized places to be found.
1GoodThe vast majority of the world is composed of good people. It can be assumed that any person you meet is benevolent with rare exceptions. Evil acts, creatures, and people are notable enough to draw a lot of notice.
2Leaning GoodThe world is generally good. Most people are good, but people are also smart enough to not assume that everyone they meet has good intentions. Evil is generally still on the fringes, but evil acts and people are fairly commonplace.
3-4NeutralThe world is neither good, nor evil. Good an evil creatures and people coexist. Notably good acts are just as exceptional as notably evil acts.
5Leaning EvilEvil is commonplace. People tend to be selfish and cruel, but because this is normal, it is possible that no one thinks that this is a problem. Evil creatures are common, and may not be considered a problem. Good creatures and people might be seen as heroes, or they might be seen as weak idealists who can’t function in society.
6EvilEvil is the order of the day. Cruelty and selfishness are idealized, and evil creatures walk the world without notice. Good creatures might be seen as pests, and “heroes” might hunt just as good-aligned heroes might hunt evil monsters.

Population Density

1d6 Description
1DesolateThe planet’s residents are few and far between. If you can see your neighbor’s chimney smoke, they are too close and its time to move out to somewhere that you have some privacy. Because residents live so far apart, reproducing might be a serious affair, and things like cities are strange and alien concepts.
2SparseResidents generally live far apart, but may gather in small villages for mutual support and security. These collectives might identify themselves as clans, they might be biologically related, or they might just be a bunch of different people that ended up in the same place. These communities must be largely self-sufficient because goods from other communities are difficult to procure.
3GrowingWhile big cities are still a rare occurance, the population is sufficiently dense that trade between communities is not uncommon. Roads between major trade partners may be permanent structures, or they might just be dirt tracks left by the passing of horses and wagons.
4PopulousMajor cities are hubs of trade and business. Most people still live in smaller villages or independent communities, but trade is sufficient to support major cities and long-distance trade between communities.
5DenseMost people live in cities. A small portion of the population works the farms outside of cities, producing enough food to feed the multitudes. Goods might come from all over the world.
6Dense+Privacy is a foreign concept. People live in every nook and cranny of the world, and there are precious few wild places. Food is a common problem as residents began living on the world’s remaining fertile lands. New ways to produce food have evolved to serve the world’s innumerable hungry bellies. Communities invent clever ways to distinguish themselves from the neighbors who press in around them on all sides.


Now that you have the major points of your world decided, fill in the details to mesh it all together. It’s best to roll all of your random features before deciding on any details, or you might find that the details you conceived don’t make sense.


Let’s say that I want to run a new Pathfinder game, and I want to set it on a new world instead of using my usual homebrew setting. I grab my d6 and a notepad, and start going down the list. For demonstration purposes, I will take one of each type of wildcard, and I will wait to decide any specific details until I have rolled everything so that I don’t have to change my details part way through.


Solar Bodies: 6 – Unexplainable, 2 – Divine/Magical: Right off the bat, my world is defined by magic. Despite a lack of any identifiable source, it has a normal day/night cycle powered by some divine power or other magical source. I’ll wait to decide on the details until I see what else I roll.

Lunar Bodies: 5 – Big Moon: My planet has an abnormally large moon.

Other Astral Bodies: 2 – No Stars: In addition to the lack of a sun, my planet has no stars. That’s awfully strange because it means that my planet and its big moon are the only two astrological bodies visible from the planet.

Wild Card: 1 – Tidally Locked: Now this is really a wild card for my planet. With no sun to be tidally locked to, it means that my planet must be tidally locked to its moon. That’s going to have some really bizarre effects on the planet’s geology.

Planetary Geography

Wild Card: 2 – Water World: In combination with the Big Moon, this is a very strange planet. Moons affect tides, and a Big Moon is going to do some very crazy stuff to a water world.


Philosophy: 4 – Neutral, 6 – Evil: A water world with strange geography and primarily evil people. Neutral Evil people will generally do whatever serves their own ends regardless of its effects on other people, which is a good way to survive in a world which is largely featureless ocean. It’s hard for someone to hunt you down and throw you in jail when you could be literally anywhere in the world.

Population Density: 5 – Dense: To further complicate my world, the population is dense. How do you have a dense population when there is little or no land to live on?


The following is my attempt to flesh out the details of the rolls above. Any notes will be in italics. If you just want to read about the setting, skip the italics and return to them later.

Agooa is a world dominated by the open sea. The few islands of the world serve as the anchors of enormous floating cities occupied by the “wooded” elite. These islands are the only source of wood in the world, so they hold a position of power over the unwooded masses banished to the open waters of the world. Wood represents safety, opportunity, wealth. A single log could mean keeping your family afloat for another year. The unwooded travel all over the world, and trade whatever they can gather from the sea in hopes that the Wooded might see fit to sell them enough scraps to continue their meager existence.

Life on Agooa is harsh, and all men live and die by the whims of the sea. A sudden storm could capsize your ship, casting you and yours into the depths, and no one would ever know. Everything that the unwooded use must come from the sea. Clothing is made of the skins and scales of fish, rope from strands of seaweed, and weapons from the bones of great creatures of the sea. Metal is an extreme rarity, coveted by those who have seen it, and spoken of in whispers by those who have not.

The skies of Agooa are barren, save for the enormous moon locked in place over the planet’s “Moon Side”. The scarred edges of the moon serve as the only permanent points of navigation for the planet below, and those sailors who dwell toward the Moon Side learn from a young age to navigate by the moonmarks. Those dwelling further toward the Moonless Side are left to wander the unmarked expanses of the sea endlessly, and might pass several generations without seeing the same island twice. The sky above shifts endlessly from night to day in perfect 12 hour increments without change, without season, without end. Time can be told perfectly by the colors of the sky at the horizons.

Far to the Moon Side, the seas grow wild and stormy. The waves rise upward as though reaching to the sky, then plunge back upon themselves. Sailors mad enough to brave these dangerous waters die violent deaths among the turbulent waters, their meager belongings are lost to the sea. What little scraps remain afloat are pulled deeper toward the Moon Side, pulled by the perpetual, gentle tide which exists below the churning storms. According to legend, a great land stands at the Moon Side, littered with the lost wealth of uncounted broken ships. If one could ever reach this fabled land, they could walk the earth for a lifetime and never again see the sea. If any have reached this land, they have not returned to share the tale.

History is largely lost to time and the sea, with nothing but oral history to spread what little knowledge of the world has been passed down. Some particularly successful families carve histories into the bones of great sea beasts in crude pictographs, but with wood so precious, justifying the space to store luxuries like carvings is hard to do. When traveling ships meet, they often meet and trade both goods and knowledge, but conflicting knowledge is common, and because these meetings are tense at the absolute best (violence is common), much of the traded knowledge is dismissed out of hand.

Here I need to deviate very slightly and add some additional world-defining stuff. While a water world might be cool to visit, it needs something more accessible and explorable to be viable for a long-term campaign in a game like Pathfinder.

Below the waves, the world is very much alive. Fish and other sea life are more than sufficient to feed those clinging to life on the surface. In shallow waters, coral reefs can be seen just below the surface, home to dizzying varieties of species, and all manner of natural treasures. Much less common, unnatural structures of stone rise up from the depths, occasionally unburied by violent storms on the surface causing shifts in the sands below, or simply wandered upon among the infinite expanse of the open sea.

Many believe these structures to be strange rock formations, mirages, or the tricks of sea hags seeking to consume the unwary. Few can say for certain, because encountering more than one in a lifetime is nearly unheard of. Occasionally a few brave souls might venture to dive down and explore the structures, but those who do often find that they are guarded by sea-dwelling predators, or that their barren faces betray no sign of their purpose or origin.

Putting it into Play

One of the most important things about Water Worlds is that they are largely covered in huge, boring water. Agooa has several points of interest to break up this monotony which can provide adventure hooks. However, I wouldn’t want to run more than one or two campaigns in this world for fear of repetition.

Mechanical Adjustments for Pathfinder

The additional complication of metal scarcity has huge implications for game balance. Ultimate Combat includes rules for low-tech weapons. Most weapons will be Bone, and weapons composed of other materials are extremely rare. You might hand-wave this by making metal weapons take the place of Masterwork weapons, or you might choose to actually use the primitive materials rules. Personally, I like the idea of exploring the unusualy materials. I might also include Obsidian weapons forged from obsidian gathered from the sites of long-dead underwater volcanoes.

Because weapons and armor made of bone are considerably weaker than those made of metal, classes which depend on weapons are considerably weaker. This means that I need to adjust spellcasting classes in order to bring them in line with non-caster classes. I can take some ideas from my Class Balance article, and make some adjustments to bring everyone in line. Because paper is basically non-existent, I will either need to ban Magi andWizards, or provide them some other means of recording spells, like scrimshawing them onto fish bones.

I really like the idea of this being a low fantasy setting, so I think that I would outright ban all full casters (Clerics, Druids, Wizards, etc.), and heavily nerf 2/3 casters. I might even go so far as to completely remove deity-based divine spellcasters (Clerics, Paladins, Warpriests, Inquisitors), and say that there are no gods on Agooa. This would help to reinforce the superstitious, disconnected feeling of the world. Magic would become almost entirely from “primal” sources, and Druids would be NPCs with powers nearly worthy of worship. Further, I might limit the players to 15 point buy when determining their abilities to make them feel very vulnerable to the dangers of the world.

Example Campaign Hook

Your boat rests at anchor, the seaweed chords gently tugging against the boat as it rocks gently on the waves. You sit at the edge of the boat, your feet dangling in the warm water. Your brother, sitting beside you, looks down into the water, perplexed. “What is it? Some kind of giant turtle?” Your cousin, sitting on your other side, leans forward to look at your brother. “That’s no turtle, you idiot. Have you ever seen a square turtle?” Your brother frowns. “Well, what is it then?”

You sit, uncertain. Below the waves, hugged by a great coral tree, a huge dark object rises from the dark waters below. It is roughly square in shape, but it is difficult to make out details from above the water. It is like nothing you have ever seen, and the curiosity eats at you. You reach behind you and grab your spear, four feet of sharpened whale bone. “Well, let’s go find out.”

Agooa would be a great setting in which to use all of those awful aquatic templates that I hate so much, and could be a great place for weird archetypes like the True Primitive Barbarian. Dungeons would be entirely underwater with rooms which range from flooded to generally damp. Think the Water Temple from Ocarina of Time. If that fills you with feelings of dread, then you should run this campaign.