Fantasy Space SRD

The mundane world of castles, cities and forests is not the sum total of existence.

While it may seem so to the average commoner, seasoned adventurers know that there are a multitude of other places out there, from other planets to alternate realities. High level adventurers will likely have fought or dealt with creatures from such places, and may well—with the right magic—visit those places themselves.

This chapter is reliant on Game Master’s discretion more than most. Things like the number of planets orbiting the sun and the number of outer planes (both of which are described in this chapter) are very dependent on the campaign setting, and therefore this chapter must be necessarily vague about such things.


The planet that adventurers live on is just that—a planet. It flies through the void as it orbits the sun. Like many planets, it’s basically a big rock surrounded by air and a bit of water. At least, that’s the assumption that these rules make. Individual Game Masters can set campaigns on very different planets if they want to.

Of course, the adventurers do not live on the only planet out there. Dark Dungeons assumes that there are a few planets orbiting the sun. This being a magical world and not our real world, some of these planets are almost always inhabitable (although not always inhabited).

The whole solar system sits in the void—an empty nothingness much like our real-world space—but the void does not stretch forever. The solar system is inside a giant sphere known as a Celestial Sphere. The celestial sphere is hundreds of millions of miles across, capable of fitting the orbits of all the planets inside it.

The celestial sphere appears to be made of a dark, smoky crystal or glass that is completely impervious to any physical force. Dotted about the sphere are huge transparent “windows” which let in light.

These windows are visible from the surface of the planets inside the sphere as stars. These windows, however, are just as impervious as the rest of the sphere.

Huge though it is, the sphere is not the only nearby “place”. There are also parallel realities called Planes.

The normal world is often called the Prime Plane, since it is the only one which is infinite in size, and it is the plane on which all others are anchored, directly or indirectly.

The other planes are split into two categories— parallel planes and non-parallel planes(*).

The parallel planes are truly parallel to the Prime Plane, or at least to the celestial sphere. Each parallel plane is exactly the same size as the sphere, and has a sun and planets in the exact same positions and orbits as those in the Prime Plane sphere. These planes have a one-to-one correspondence with the Prime Plane in that every point on the Prime Plane has a corresponding point on every other parallel plane. If you travel from the Prime Plane to the Ethereal plane, then sail 20 miles, and then travel back to the Prime Plane; you’ll end up 20 miles from where you started.

Godly domains, on the other hand, are different. These planes are created by Immortals, and can be as varied as their creators’ whims dictate. (*)

One thing they have in common, however, is that each one has a single point where it is “anchored” onto another plane (often the Prime Plane, but theoretically any plane will do). The anchor point is the only point with a fixed correspondence to the plane that it is anchored to. If you travel to an outer plane at the anchor point and then walk, fly or sail 20 miles, you simply won’t be able to travel back without either returning to the anchor point or using magic such as a Gate spell.

And that is not all…

The celestial sphere itself can be penetrated with powerful magic. Outside the sphere is a strange glowing substance, if substance is the right word, called the Luminiferous Aether. Sail or fly through this for long enough and you’ll encounter other celestial spheres—each of which will contain its own unique set of planets and will have its own inner and outer planes attached.

However, all planes are attached to the Prime Plane inside celestial spheres. In the luminiferous aether there are no other planes.

The rest of this chapter looks at these different locations and phenomena, how to survive in them, and how to travel to and through them.

The Void

The void is the empty space between worlds. As the name suggests, it is completely empty, not even containing air.


There is no gravity in the void away from large masses, so any unsecured object will simply drift randomly. Because of the lack of air, creatures with wings will find it impossible to fly; although magical flight still works.

Any mass in the void, from the smallest pebble to the largest planet or sun will have its own gravity. However, unlike our world this gravity does not always pull in the direction of the centre of the mass and is not directly proportional to the mass of the mass(es) involved.

Instead, the strength of the gravity around an object or group of objects is always the same; the distance over which that gravity acts is limited and based on the size of the object or group of objects; and the direction of the gravity is based on the shape of the object.

Strength: The strength of gravity is always simply the normal strength of gravity that is found on the real-world Earth. Within the gravity envelope of a planet, big or small, things fall just as expected.

Distance: The distance away from an object to which its gravity extends is based on the width of the object in the direction in which the distance is being measured. That’s less complicated than it sounds. Basically it means that the gravity envelope for an object stretches as far above the object as the object is tall, as far to either side of the object as the object is wide, and as far in front of and behind the object as the object is deep. The gravity envelope is therefore the same shape as the object but three times the size (and 27 times the volume).

However, there is a limit to the size of the gravity envelope produced by an object. The envelope will never be more than fifty miles deep no matter how large the width of the object is.

Example: The Game Master has decided that the campaign is primarily set on a planet the size of Earth—a spherical planet of approximately 8,000 miles diameter. In theory, the gravity envelope of this planet would therefore also be spherical and stretch 8,000 miles in every direction. However, gravity envelopes cannot be more than 50 miles deep, so instead it spherical and stretches 50 miles in every direction.

The party are travelling through the void in The Black Swan—a skiff that has been equipped with an astral keel. The Black Swan is 45’ long, 15’ wide and 8’ tall. The gravity envelope of this ship is therefore an area 135’ long, 45’ wide and 24’ tall. In theory, there is a thin bit of the envelope that sticks up in the middle where the mast of the ship sticks up, but practically that can be ignored for most purposes.

Direction: The direction of gravity within a gravity envelope is determined by the shape of the object that is responsible for the envelope. Each gravity envelope will have a consistent direction of gravity throughout, and if the shape of the object responsible for the envelope changes there may be a sudden flip from one gravity direction to another. Different parts of the gravity envelope will never have different directions.

The three most common directions are point, plane and line gravity.

If the object responsible for the gravity field is roughly spherical, such as a planet, then throughout the gravity field gravity pulls towards a point in the centre of the object. This means that it is possible to walk all round the sphere without falling off.

If the object responsible for the gravity field is roughly cylindrical, then throughout the gravity field gravity pulls towards the central line of the cylinder. This means that it is possible to walk all around the cylinder without falling off, but it is possible to fall off either end of the cylinder. Anyone doing so would oscillate back and forth until they settled next to the end of the cylinder lined up with the mid point. The gravity envelope would prevent them from “falling” further, but there would be nothing to stop them drifting away in a direction perpendicular to the cylinder’s end.

If the object responsible for the gravity envelope is roughly flat, such as a ship, then throughout the gravity envelope gravity pulls towards a plane that cuts through the middle of the object. This means that it is possible to walk around on the upper deck(s) of the ship without falling off, and it is also possible to walk around on the underneath of the ship’s hull without falling off. However, it is still possible to fall off the side of the ship, and someone doing so would oscillate back and forth until they settled next to the side of the ship lined up with the mid plane of the ship. The gravity envelope would prevent them from “falling” further, but there would be nothing to stop them drifting either along or away from the ship whilst staying on that same plane.

In the case of large objects with unusual shapes, these may have different gravity directions at the Game Master’s discretion. For example a large hollow sphere might have gravity pointing towards the middle of its thickness, meaning that the inside and outside of the sphere can both be walked on; or a large doughnut shaped object might have gravity pointing to a ring through its centre, so that it can be walked around without falling off.

If in doubt, use the direction of gravity that seems the most sensible and convenient.

In any case, when a small object enters the gravity envelope of a larger object, the smaller object takes on the gravity envelope of the larger object.

Example: The Black Swan, like most ships, is roughly flat; so its gravity points in the direction of its central plane. People can stand on both its deck and the underneath of its hull without falling off.

When the ship approaches a planet in order to land, it will take on the gravity envelope of the planet. The safest way for Aloysius to manage this transition without everyone falling off is to manoeuvre the ship so that its hull is facing the planet. That way gravity will still be pointing “down” through the hull and people on the decks will not fall off.

Air and Breathing

The void itself contains no air of any kind. However, the objects within the void will normally be surrounded by an envelope of air that clings to them because of their gravity envelope. The air envelope is generally the same size as the gravity envelope.

Unfortunately for travellers, the air around a creature or object will go “bad” and become unbreathable if it is not replenished regularly. Large planets don’t have this problem—partly because of the sheer size of the air envelope around them and partly because they have whole ecosystems constantly replenishing the air.

Air quality is divided into three levels of quality: Fresh, Fouled, and Dead.

Fresh Air: Fresh air is healthy and normal. Creatures can survive and operate in it without problem.

Foul Air: Foul air is unhealthy, humid and smells bad. Creatures can survive in it, but will often be short of breath and take a –2 penalty to all actions that require rolls.

Dead Air: Dead air can no longer support creatures at all. Creatures trapped in dead air will suffocate to the point of unconsciousness over the course of 2d6 rounds and then die in another 1d4 minutes. Before unconsciousness sets in, creatures in dead air take a –4 penalty to all actions that require rolls.

A character who is about to knowingly enter an area of dead air can hold their breath for a number of rounds equal to their constitution before symptoms start.

The exact time it takes for a creature to foul its own air envelope to the point where it drops a level in quality (if drifting in the void) depends on a multitude of factors and variables; and is best abstracted to a roll of 2d10x10 minutes. Larger creatures take more air with them, but also use more air; so the result is the same.

Undead, constructs, golems, and Immortals (unless in Mortal Form) do not foul the air that they carry around, since they do not need to breathe, and they also take no penalties for being in fouled or dead air.

In the case of people on a rock or on a ship, the object that they are on will provide a much bigger air envelope, so it will last much longer before becoming foul. Although the amount of air in the envelope would be most accurately determined by the exact shape and size of the object and many other factors; it is best abstracted by the following (particularly for ships equipped with astral keels):

For each ton of weight of the object, it’s air envelope will last one person 120 days. Horses and large creatures use the same amount of air as two people (or even more in the case of extremely large creatures).

Example: The party travelling in the Black Swan consists of four people. The ship weighs 5 tons (it’s a skiff), and can thus support 5 x 120 = 600 person-days. Therefore it will take 600 / 4 = 150 days for the air to become fouled and a further 150 days for the air to become dead. The ship cannot safely travel for more than 300 days (with this crew) before landing on a planet to refresh its air supply.

The Create Air spell always maintains fresh air within its area of effect for the duration of the spell, but once the duration runs out, the air returns to its former fouled or dead state.

A person under the effects of a Survival spell does not suffer the effects of foul or dead air for the duration of the spell.

Movement & Travel

Getting to the void is easy. It can be done by simply flying up for long enough to reach the edge of the planet’s air & gravity envelope.

However, assuming that the campaign is set on an Earth sized planet, this envelope will be 50 miles deep; so while creatures flying under their own power may be able to fly that distance they are unlikely to fly that high by accident.

Ships equipped with astral keels can easily traverse such distances. However, since the ships need to gather enough energy to fight gravity all the way, it takes an hour of collecting rowing energy and another full hour to reach the edge of the gravity envelope.

While doing such a take-off, the ship cannot do other navigation at the same time, unless it has some other means of overland flight in addition to the astral keel. It can only go straight up while ascending. Landings are impossible for ships of 20 tons(*) or greater. For ships less than 20 tons, they need a feather fall enchantment in order to not be destroyed upon completing a fall through the atmosphere.

Once outside of a gravity envelope, any form of magical flight will work as normal, although winged flight will not unless the creature’s description specifically says that it can fly through the void. Winged creatures that do fly high enough to reach the edge of the gravity and air envelopes will be able to feel that they have reached the edge and non-intelligent ones will instinctively go no higher.

Once in the void, the main difficulty with travelling through it is that the distances are so immense. The distance from one planet to another may be anywhere from 36 million miles to 3.5 billion miles or more; and the radius of a celestial sphere can be up to 7 billion miles. Getting from planet to planet is therefore only possible with magic designed for that purpose. Normal magical flying effects or items are far too slow to even attempt the journey. Even a simple trip to a planet’s moon is likely to be at least 200,000 miles.

Ships equipped with astral keels are one of the few commonly found magical effects designed for such long distance travel.

The speeds listed for such ships in Chapter 12 are the speeds within a gravity envelope. Once a skysailing ship has escaped the gravity envelopes of nearby planets and is in the open void, it can accelerate to Voidspeed. Unlike the speed s achieved in atmosphere , voidspeed is not dependent on the effective level of the pilot of the ship. It is fixed at 100 million miles per standard 8-hour travel day. As with air travel, the pilot of the ship can do a “double shift” if the need arises. See Chapter 12 for more details.

This immense voidspeed can only be maintained in a straight line. Any need to manoeuvre will cause the ship to drop to normal air speed. Similarly, entering the gravity envelope of another object will cause the ship to drop to normal air speed.

No encounters are normally had in the void, since the distances and speeds involved are so huge that the odds of two ships actually coming close enough to even detect each other are astronomically low.

When travelling from planet to planet, it is not necessary to calculate the exact orbits of each planet in order to find out the exact distance between them. Instea d, simply use a standard “average” distance between each planet.

Example: Aloysius is piloting the Black Swan home after visiting another planet. The two planets are the same distance apart as the Earth and Mars—about 50 million miles.

Aloysius flies the Black Swan straight towards home at voidspeed, and arrives at the edge of the gravity envelope (50 miles above the surface) in 4 hours. He then manoeuvres the ship so that its hull is facing the planet, and lowers it into the atmosphere. The time taken to descend through atmosphere is always 1 hour, so it takes a further hour to bring the Black Swan down to within a few hundred feet of the ground.

While descending, Aloysius checks on his maps to see whereabouts on the planet he is, and then sets off at cruising speed to get to the skyport of his choice. When he has both arrived and finished descending (whichever takes longer) he will switch to manoeuvring speed in order to land carefully.

The Celestial Sphere

Although incredibly huge, the void is not endless. It is bounded by a shell of crystalline material called the Celestial Sphere.

The sphere is impervious to any physical or magical damage, even from Immortals.

Assuming your campaign world is not terribly unusual, the sphere will contain either a sun in the centre with a number of planets orbiting it, or a central planet that is orbited by a sun and one or more other moons and planets.

In either case, the radius of the sphere will always be at least twice the radius at which the outermost planet orbits.

Example: If the campaign was set on a planet like Earth (third planet of nine from the sun, if we include Pluto), the radius of the celestial sphere should be at least twice the radius at which Pluto orbits.

Pluto orbits at a radius of 3.6 billion miles from the sun, so therefore the sphere would have a radius of at least 7.2 billion miles.

At standard Voidspeed, it would take a ship 72 days to reach the edge on average.

Dotted around the sphere are glowing points of light that can be seen as stars from the various planets in the sphere. These are a part of the sphere, and cannot be moved or damaged in any way. However, they are useful for navigation, and provide a dim light in the absence of a sun.

Astronomical Bodies

The astronomical bodies—planets and sun(s)—in the sphere can be loosely categorised into four types, corresponding to the four states of matter:

Gaseous Body: A gaseous body is a gas planet. The body of the planet is made of air or some similar gas, and it is not usually possible to tell where the air envelope stops and the planet itself starts. A gaseous body may have a small core at the centre, composed of debris that has accumulated there, but generally it is entirely composed of air. A gaseous planet usually has extremely violent weather patterns.

Solid Body: A solid body is a solid planet like our own Earth. It will be primarily composed of rock, and have a normal atmosphere. Dark Dungeons assumes that the campaign is set on a solid body.

Radiating Body: A radiating body is a sun. There is usually one per sphere, and it is often in the centre. A sun provides light for the whole sphere; without a sun the sphere is dark and lit only by the stars. However, a sun is not necessary to provide heat in the void. A sphere without a sun will be cold enough to freeze water, but will still be warm enough to survive in.

If the gravity and air envelope of a radiating body is entered, treat it as if on the elemental plane of fire, with the exception that there is no ground. The planet is usually fire all the way to the centre, since any debris that would accumulate there will typically burn up.

Liquid Body: A liquid planet is basically a large blob of water or a similar liquid, forming a planet that is entirely sea. It may have a small core made of debris, and may also have small islands of floating debris, possibly even with settlers or refugees living on them. The atmosphere of a water planet is normal.

In a sphere without a sun, a liquid planet will be a frozen ball of ice and snow rather than liquid water.


Inside every celestial sphere, occupying the same space as the mundane world are major and minor planes. These planes make up the microcosm of the material plane, a sort of mini-cosmology unique to that plane. Major planes take up the same amount of space as the mundane world, and come in parallel and non-parallel(*) varieties.

The Parallel Planes

Inside the celestial sphere, there is not just the mundane world (known as the Prime Plane). There are also parallel worlds that take up the same space as the mundane world. Such parallel worlds are called Planes. Each of them is finite in size and surrounded by the same crystalline sphere.

There is an exact mapping between the parallel planes and the prime plane, in that each parallel plane has its own copies of the astronomical bodies contained in the prime plane, and these bodies contain the same rough geographical features (mountain ranges, seas, etc.) as those on the prime plane. However, artificial structures and vegetation will not be mirrored.

The correspondence between the planes extends to movement as well. If someone travels from the prime plane to the ethereal plane, travels north for a mile, and then returns to the prime plane; they will arrive one mile north of their starting position.


Non-parallel planes do not have the same celestial bodies as the mundane world. Instead these solar system sized planes can have any property imaginable.