Mock Logic Games

Cosmonomicon Repost

This is a repost of an article originally posted on the Mox Boarding House / Card Kingdom website from late 2015.

I’ve always loved flying ships in my D&D.  I own a copy of the 2nd Edition D&D SpellJammer setting. I have the Polyhedron magazine issue of SpellJammer: Shadow of the Spider Moon for 3rd Edition D&D, and I owned much of the DragonStar 3rd Edition D&D setting. In other words, layering space opera onto D&D is something I’ve enjoyed for years. Even my 4th Edition D&D Eladrin character ended up building an armada of magic flying ships that traveled the planes in his epic levels.

So why not bring some of that back to 5th Edition?  Here is a fun blend of Spelljammer, Spidermoon, and Dragonstar, with an eye towards play in 5th edition. A swashbuckling D&D-in-Space setting where players can sail ships across the stars, battle a corrupt empire, and deal with horrify invaders.  A setting where you can borrow your favorite parts of Pirates of Caribbean, Star Wars, and Firefly without giving up your elves, dwarves, dragons, and even the dungeons.

The Sea of Stars

The darkness of the night sky, dotted with uncountable stars: for many cultures the stars are arranged in mysterious symbols representing gods and heroes, but to the most learned of sages and wizards, it is known that each star is another world or distant ball of pure elemental fire like the familiar sun.  Some have not been content to merely gaze at the sky and chart the movements of the stars. They have built magic vessels, enchanted ships to escape the gravity of their worlds and see what lies beyond. These explorers have taken to the void between worlds; to learn, to make their fortune, to conquer, and in time some even built massive empires.

Each star in the galaxy hosts a collection of worlds in orbit around them. Many are dominated by large amounts of particular elements: gas giants, watery blue worlds, icy moons, sandy desert worlds, and even planets of fire and magma. Others host more diverse climates. Many are inhabited, home to some combination of humans, elves, dwarves, orcs, and monsters like dragons. The galaxy is heavily populated, with many worlds and moons that are able to support life, although many host extreme conditions and support only limited diversity of that life.

The solar systems that make up the galaxy are many, but space in incredibly large.  Even with the aid of magic ships, the time it takes to travel between worlds numbers in days or weeks, and the distance between stars is insurmountable. That is what makes the crystal gates so amazing. These massive crystal structures link solar systems and are large enough to pilot a dozen crafts through at once. The Celestial Church teaches they were built by the gods themselves when the galaxy was young and freshly created: gifts to their mortal children when they were capable of finding them. Each gate is a constantly open two-way door between two neighboring star systems.  Most solar systems host several gates linking them to their neighbors, but even in the most busy of systems new gates are sometimes found. Most gates are located on the outer edge of the solar system out beyond the orbit of the planets, somewhat aligned between their host star their destination star.  Some are found elsewhere, having been placed there or moved by powerful forces. Some rare gates seem to link far more distant systems, forming a kind of hub for travel from one edge of the galaxy to the other.

The ships that ply the space lanes traverse these gates to travel throughout known space.  Those willing to take a journey of a several years could travel from one end of the galaxy to the other, although few people travel so far from home, and fewer still know the location of enough crystal gates to make it possible.

Because the gates are so hard to locate in the darkness of space and are often located a week or more of travel out past the last planet of a system, many gates along key space lanes possess lighthouses and small port cities just past the portal on either side, especially in the more densely traveled and populated inner core of the galaxy.  On the outer edges of the galactic empire, few ships travel, and “groundlings” that live on the worlds are nearly all unfamiliar with space travel. Here gate locations are more difficult to come by.

The Races of the Galaxy

There are many inhabited worlds within the galaxy, but the races of each of them are often more alike than dissimilar. Biologically, dwarves are dwarves no matter what world they come from. Moreover, they often speak the same language, if with variation on accent, and worship the same or eerily similar gods. The Celestial Church teaches this is because all the worlds were made by the same gods, and seeded with life according to their divine plans.

These matching races and languages has often made cooperation between races from different planets or star systems easier to form. The elves from a forest moon are often able to find common ground with the island dwelling elves of a largely water world.  Still, conflicts between and within races are not unheard of, especially among human kingdoms.

Each race tends to have a similar style of craft that they use for their travels along the space lanes. The size and exact style of each craft can vary widely, but few people could mistake a dwarven carved stone ship for an elvish grown treeship. Humans tend to convert sea faring vessels to space travel, and use magic sails to travel both. Elven tree sheeps are grown not built. Dwarven furnace ships are carved of stone and powered by enchanted furnaces and coal. Dragonborn ships are built to slightly resemble dragon silhouettes and are powered through magical “spelljamming” thrones that drain arcane power from their sorcerer users as fuel. Perhaps the most odd of starships are the tinker gnome contraptions, semi-mechanical crafts whose aether screws are powered by everything from steam-engines to giant space hamsters in massive wheels.  Not all crafts are said to be powered in such benign ways. Drow spider-ships are rumored to be powered by draining the life from captives trapped within magical webbing inside their hulls, and tiefling were said to have crafted ships powered by bound infernals or human souls.

All Hail The Dragon Emperor!

The central core of the galaxy is Draconic Space: An empire of thousands of solar systems that   has been ruled by a succession of emperor wyrms, going back 597 years to the Draconic Accords that ended the Galactic War between the Chromatics Clans and the Metallic Houses. Under the terms of the Accord, each color of the ten dominant dragonkinds rules for a hundred years, and the core worlds of the galaxy have been at peace for nearly 600 years, as the Metallics, dominant in the destructive war but looking to end the carnage, took the first half of the imperial rule. Unfortunately the last Golden Empress peacefully abdicated the imperial throne to the first Red Emperor, Xentarious, nearly a hundred years ago. Xentarious immediately begun changing the empire to suit his own desires and plans, and as his reign near it’s official end, it is an option question if he will yield the Dragon Throne peacefully or risk a new galactic war in a bid to retain power.

The inner most systems of the empire are under direct imperial control. On these worlds, dragons hold the highest seats of power, with their dragonborn servants often acting as go-betweens, elite soldiers, and occupying various positions of power in the humanoid societies of the ruled “citizens.” Each dragon dominated planet is often a reflection of their dragon lord ruler, with chromatic ruled worlds often far less pleasant for the humanoid citizens than those of the metallics. Emperor Xentarious, for example, has many ties to a drow house dominant in his home system. Upon his rise to emperor, he installed the drow has new inquisitors and secret police. It’s now common to find Drow inquisitors on imperial ships and in imperial offices.

Beyond these inner worlds, numerous smaller kingdoms still fall under the Draconic Empire’s domain.  In these systems, a Draconic Governor nominally oversees the local worlds on the emperor’s behalf, but the local kingdoms and other governments are left more or less intact. These governors maintains power through draconic guile and the might of the Dragonborn legion placed at their beck and call.  Few nations dare to openly oppose the empire, especially since the “Rebellion of the Devil-Chained Kingdom” some 430 years ago when the Silver Emperor crushed an interplanetary kingdom that openly rebelled, had even their name eradicated from the records, and scattered the surviving tiefling bloodlines to the winds.

The fringes of the empire contain many systems that are officially claimed for the empire on various star charts, but are largely unsupervised. On many of these “backwater worlds” the nature of space travel is still unknown to the groundlings, who spend their time fighting each other for dominance of a particular kingdom or continent, unaware of the interplanetary empire that claims dominion over not only their world, but even their moons and sun.

Almost immediately upon coming to power, Emperor Xentarious initiated a change in policy regarding groundling worlds in the periphery of the empire. He begun sending the dragonborn legions backed by humanoid conscripts and drow inquisitors into the fringe worlds. Legion backed imperial ambassadors meet with local rulers and demand they bend the knee to the empire. Most worlds have at least one major kingdom that refuses to do so, and the legion envoy leave “peacefully.” They then drop an asteroid on that kingdom, causing massive destruction and death.  Typically the rest of the planet yields and accepts a new draconic overlord; one that owes fealty to Xentarious. Within the core worlds, this policy is sold to the public as bring these barbarian worlds into the fold of galactic society, although it isn’t hard to see what’s really going on. Of course speaking out against the policy is not a safe or healthy if the imperial inquisitors find out.

Beyond the Borders of Draconic Space

The Dragon Empire does not, yet, dominate the entire galaxy. Various arms of the galaxy host other rival and neighboring societies, and much of the galactic rim is still unexplored by the empire.

The Thri-Kreen Matriarchies

The dragon empire has a border with an expanse of space dominated by space faring Thri-Kreen. Their is no official communication between the Dragon Empire and the Thri-Kreen queens, but over the centuries an unspoken understanding has formed that neither side will send forces or colonies into the border systems between the two nations. Minor incidents by both sides have occasionally happened, but so far none of them have sparked any large conflicts.

Dark Nebula

A blight cutting off one arm of the galaxy from the central core, the stars and worlds within this massive dark cloud of interstellar dust are poorly explored. Sailors tell terrible stories of disturbing nautiloid shaped crafts crewed by mindflayers and other abominations lurking within the dim systems of this region of space. Sages speculate that the mindflayers commonly found  in the underdark of various worlds are actually the descendants of a once mighty mindflayer empire that reached across the star, and that the mindflayer homeworld is within the dark nebula. This hypothesis supposes that mindflayers only arose on a single world, and that they were not created by the gods, but instead some terrible confluence of events, possibly linked to the Far Realm.

Darkstar Confederacy

The region of the galactic arm controlled by the confederacy is actually home to many small kingdoms and world governments, but the major power of the region is the Confederacy: a loose affiliation of pirates and raiders that dominate the region. Each pirate fleet or force in the confederacy has carved out a region of space for themselves, and survive by raiding or extorting resources from the weak nations on the planets in their turf. Minor conflicts for territory between pirate fleets is common, but a pact of mutual protection in the face of external threats binds them all together when necessary. Past attempts by the empire to send a small fleet to clean up a single “pirate problem” have therefore yielded stronger than expected responses from the Confederacy as a whole.

Celestial Church

The Celestial Church is the official religion of the Draconic Empire.  The central tenant of the faith is that the same gods have appeared in many incarnations to many races on many planets; that there are in truth only nine true gods, each with uncounted guises and mythologies. Under the teachings of the celestial church, the same god that appears as Moradin to the dwarves is also Bahamut to the Dragonborn, and dozens of other gods to the myriad of people across the galaxy.

Within the more civilized core of the empire, the gods are most frequently worshiped in their “true” forms, but the priests of the Celestial Church also see it as their sacred duty to catalog and analyze the myriad forms and teachings the Nine have used across the multitude of worlds of the galaxy.

  • The Crusader, god of protectors (LG, Shield Symbol) – War, Life
  • The Architect, god of creation (NG, Tool Symbol) – Light, Knowledge
  • The Lover, god of relationships & family (CG, Rose Symbol) – Nature, Life
  • The Judge, god laws (LN, Scales Symbol) – Knowledge, Tempest
  • The Gatekeeper, god of fate and death (NN, Key Symbol) – Knowledge, Nature
  • The Traveler, god of commerce and travel (CN, Wheel Symbol) – Trickery, Tempest
  • The Tyrant, god of war and tactics (LE, Sword Symbol) – War, Tempest
  • The Thief, god of criminals and trickery (NE, Snake Symbol) – Trickery, Death
  • The Destroyer, god of fear and carnage (CE, Flame Symbol) – Tempest, Death

Rules For D&D


Space is a massive expanse of weightless vacuum.  Within this colossal expanse sit planets orbiting stars, which in turn slowly orbit to form the galaxy.  In this way “space” in the Cosmonomicon setting is very much like space in the real world.  However, the details are not the same. Stars are burning spheres of fire connected to the elemental plane of fire. Planets and moons are likewise made of the combination of 4 elements: fire, water, earth, and air. The hand of creator gods can be seen in their formation. Particularly striking is the abundance of life populating the many habitable worlds. Nearly every large asteroid, moon, or planet is at least able to support life, with reasonable gravity and a breathable atmosphere.  Most of these worlds actually contain life, and that life is similar from world to world and solar system to solar system.

Planets in this setting are often largely of a single biosphere: desert worlds, forest worlds, water worlds dotted with islands, etc.  Such “one note” worlds tend to be dominated by only a few intelligent races that are best adapted to that environment. A forest moon, for example, might be home to just elves, fey, and goblinoids.  There are exceptions of course: some 10% of planets host complex environments and multitudes of sentient life like those found in most major D&D settings.

Gravity and Atmosphere in the setting are largely simplified to encourage easy gameplay and to mimic the tropes of old Sci-Fi: sufficiently large objects in space, starting with big asteroids and ranging up to planets more massive than Earth, possess gravity similar to Earth.  Low gravity worlds might be closer to Mars than the Moon, while large dense planets might be a bit “heavier” than Earth, but they are all readily available to adventure on.  Similarly, these bodies possess breathable atmospheres thick enough to at least be somewhat comfortable to humanoids. Particular worlds might be a little thin and cold, or dense and heavy, and it’s not uncommon for particular worlds to smell differently, or even to be dangerously toxic or acidic, but they seem to always contain enough oxygen to breath and be thick enough to not require suits.

Metaphysically, the cosmology of the setting is still the default of D&D: The Great Wheel (PHB p300, DMG p44).  The galaxy and the wider universe are all the material plane.  The inner and outer planes also exist, just as described in the core D&D books.  Similarly, the material plane also possesses its echoes: the Feywild and Shadowfell. That means every planet, moon, asteroid, and star has it’s own echoes in those planes.  In the empire, these dimensions are sometimes called Shadow-Space and Fey-Space.  Space travel is not especially common in these dimensions, largely because no crystal gates link solar systems in these echo dimensions  Strangely, the layout of stars on any given world does not match those in fey-space implying that while every world has a mirror in these other dimensions, the galaxy is not laid out in the same fashion. Stars in Shadow-space do not burn with any light, and therefore no constellations are visible.

Starships of the Cosmonomicon

Even the largest starship is not large enough to have their own gravity and atmosphere, but wizards long ago learned to artificially generate these effects on their starships with magic. Most ships have redundant runes or other magical features worked into them at creation which provide gravity and a magical “air envelope.”  Gravity on most ships is orientated as you would expect, although some avant-garde starship designers sometimes configure in less familiar fashions.

The “air envelope” is in some ways like a magic bubble that holds in a breathable atmosphere, although it lacks a distinct edge surface as you would find on a true bubble. This envelope is larger than the ship, typically extending away from the hull by a fair amount of distance proportional to the size of the ship.  This serves two purposes: first, the envelope is large enough to provide breathable air for a ship’s crew for a fairly long period of time. More so than if the air was limited to just 10’ away from the hull like gravity.  Second, the envelope is large enough to wrap around small asteroids of wrecks that the starship might dock with to explore, providing air for that exploration.  Air envelopes only work in a vacuum. They provide no benefit underwater or in toxic or otherwise dangerous atmosphere.

Because both these effects are provided by magical means, this makes ships vulnerable to anti-magic fields. The redundant nature of the magic limits this because it typically means a majority of a ship must be in an anti-magic zone for gravity or the air envelope to dramatically fail.  Smaller anti-magic fields, like those of a Beholder’s main eye, aren’t generally a major threat, at least in terms of gravity and air envelope.

Air envelopes keep an atmosphere around a ship, but they don’t provide a way to refresh that atmosphere; to scrub carbon dioxide and provide breathable oxygen. Air envelopes are typically large enough that they can support the crew of any given ship for four weeks before the air becomes dangerously “stale,” and can be refreshed by landing on a planetoid. Ships expecting to make longer journeys without making planetfall have to take further precautions.  Elven tree ships operate in a kind symbiosis with the humanoid crew, turning their exhaled breath into fresh air.  Other starships tend to make use of magic lanterns that magically burn air back into freshness.  As long as the lantern is burning, using normal lantern fuel, it is converting stale air into fresh.

For simplicity sake, exposure to the vacuum of space is handled as suffocation, PHB p183, combined with an effect mechanically the same as being in Frigid Water, DMG 110. This means undead, which do not breath and typically can not be exhausted, are immune to the hostile nature of the environment, but not to final effect: silence.  The lack of air in the void means it can transmit no sound. It also means that non-magically fueled fire is immediately snuffed out.


Technology in the Draconic Empire is slightly more advanced than on “grounder” worlds. Of particular note is the development of gunpowder. Muskets, Pistols, and even bombs are accessible within the empire. Use the rules as provided on  page 267 of the DMG. Cannons, DMG p255, are fairly common weaponry on starships within the empire. For members of the empire, muskets and pistols count as martial ranged weapons.  For “groundlings” the weapons are typically unfamiliar, at least at first, but for those with martial weapons training, they can develop the proficiency with downtime training. Like any other ranged projectile weapon, firearms and bullets can accept magical improvements just like bows and arrows.

Space Magic

Magic within the setting works more or less as expected, because it’s magic.. It is possible, for example, to cast a fireball into the vacuum of space because the fireball isn’t burning, it’s a burst of elemental fire brought into existence by magic.

Teleportation magic allows for some potent feats of travel within the galactic empire. Because the entire galaxy is all on the material plane, it is possible to teleport from world to world or even clear across the galaxy. The mishap table continues to apply, so “off target” when traveling light years tends to mean landing on a planet in the wrong solar system. Interplanetary mishaps are especially dangerous as they can drop a target onto a sun, in the cold vacuum of interstellar space, or worse. For this reason most people using teleportation magic to travel between worlds do so with teleportation circles, or not at all. The potential downsides teleportation magic, along with limits on capacity, are among the reasons that starships are continued to be built.

“Star-Pact” Magic is not entirely uncommon in the Cosmonomicon setting.  Warlocks with the Great Old One as a patron often say they can hear things whispering from the dark spaces between solar systems, or from particular regions. Spells like Hunger of Hadar seem to make it clear that some parts of the galaxy are extremely hostile, or thin enough that the Far Realm can leak through. The infamous star Hadar, for example, shines out from just within the Dark Nebula and is linked to many dread prophecies in the myriad cultures of the empire. No sane explorers have managed to return from visiting the Hadar system.

Space Monsters

Monsters are typically found where you expect them: in ruins, caves, and dark corners at the edge of society. It’s just that those locations are now in space.  An ancient mummy might dwell in nearly forgotten tomb, but that tomb is located on an obscure asteroid. The players might battle undead dragonborn on the wreck of a starship lost in the Dragon War, eventually facing off with the dragon ghost that was its captain. Farming colonists on a fringe world of the empire might beseech the players for help fending off orc raiders in a stolen starship.

Some monsters, however, may be more fun if they are updated to better fit the setting. Space whales a hunted for their valuable meat and blubber. Space krakens have been known to destroy ships that enter their territory, etc. Here is a simple monster Template for making such creatures:

Space Monster (Template)

Any Beast, Dragon, Monstrosity, Ooze, or Plant with a flight or swim speed can be made into a Space Monster.

Lost Characteristics: Change or remove any abilities related to making or detecting noises.

Speed: Change the Swim speed, if any to Fly speed.

Senses: Gain Darkvision 120 ft. but lose any echolocation or sonar related Blindsight.

Conditional Immunities: Space Monsters are immune to Vacuum. Because they don’t breathe atmosphere at all they are also immune to Suffocation in general.

Character Creation

Character creation for the Cosmomicon setting is unchanged from those of core D&D.  Given the large multicultural nature of the Dragon Empire, just about any race could be encountered in a star port, so GMs are encouraged to allow races from any setting supplements they feel comfortable with. All of the races in the Player Handbook are expressly allowed.


The official language of the empire is Draconic, and frequently spoken by dragon lords and their dragonborn servants. It is the language of rulership and law.  “Trade tongue” however, is the most frequently known language in the empire, and is essentially the Common language from the PHB, p123.  For characters from the Draconic empire, the Draconic language can be treated as a Standard instead of Exotic language.

Notes on Backgrounds

Acolyte: The Celestial Church is the most common religious pantheon in the Empire. Characters can choose to serve the church as a whole, or be devoted to one the Nine in particular.

Guild Artisans: Shipwrights and Sailmakers make for highly useful backgrounds in the Draconic Empire.

Noble: Dragonborn nobles may be associated with one of the Metallic Houses or Chromatic Clans of the central core of the Empire.  Other races as nobles likely hail from the subject kingdoms whose families rule a few planets but are themselves subject to the Emperor.

Outlander: You either hale from a Grounder world, one that has not been brought into spacefaring society, or from a world outside the Empire’s borders.

Sailor: Instead of an ocean going nautical sailor, you could a starship sailor.  You have proficiency with Vehicles (Space) instead of Vehicles (Water.) Similarly, the Ship’s Passage feature applies to starships instead of ocean going vessels.  This is highly useful if the character do not have a ship of their own, yet.

Pirate (Variant Sailor): The Black Star Confederacy is a region of space ruled by space-pirate fleets, but smaller space-pirate operations can be found in many corners of the empire.

Soldier: This background works best if military implied is the Draconic Empire’s legions. The Draconic Empire is famed for their Dragonborn Shock Troopers, but the Legions are not picky about what races they recruit, especially as part of the new emperor’s conquest of the fringe worlds. The legion has grown considerably in the last 99 years, and many veterans cut their teeth pacifying grounder worlds.

Magic Items

Lantern of Air Purity (Wondrous Item, Uncommon)

Frequently used on ships making long trips, this magic lantern not only provides light like a normal lantern, but as it burns it converts stale air into fresh, undoing a half hour’s worth of breathing for each minute it burns, or negating 30 people’s worth of breathing for each minute it is active.  The lantern burns oil just like any other lantern, but the light tends to take on a blue-ish tinge, becoming more blue the more stale the air is.

Conjuring Musket/Pistol (Weapon/Firearm, Uncommon, Requires Attunement)

These magical firearms conjure their own ammunition, making it possible to fire it without first Loading it or even having access to gunpowder or bullets. The gun starts with 7 charges and regains 1d6+1 at dawn each day. They can be loaded and fired normally as well, and counts as a magic weapon.

Air Envelope Necklace (Wondrous Item, Uncommon)

These magic necklaces provide protection to their wearer against vacuum exposure, and are sometimes used by explorers that need to inspect areas beyond a ship’s air envelope. They always generate at 2’ air envelope around themselves, and provide immunity to vacuum exposure to their wearers immediately when worn.  The air envelope provides up to 4 hours of breathable air for it’s user.

About The Author

Brian Danford’s 4th edition Eladrin Artificer was Lord Admiral Arannis of House Dayereth; Planeshifter and Star-Called Radiant One; Child of the Fey City of Mithrendain; Huntsman in the Order of Arcane Archers; Huntmaster of the Archfey Culhoch; Blood Sacrifice unto Orcus; Survivor of the Well of Demons; Crafter of the Seven Sisters of Silver Star Armada: Storm Maiden, Twilight Princess, Rain Mother, Dawn Queen, Nightsong Mistress, Lady Starlight, and Dusk Priestess; Builder of the Twin Sky Fortresses of Far Star and Moon Home; Forger of the Blade Silver Oath; and Faithful Servant of the Fey Gods Corellon and Sehanine.

Art Credits

The Spelljammer cover belongs to Wizards of the Coast. The Spidermoon cover also belongs to Wizards of the Coast, although the magazine if comes from was Piazo. The DragonStar cover belongs to Fantasy Flight Games, although the D20 logo belongs too… look I’m not a lawyer, but I’m trying to do this part Fair Use.

All the other artwork in this article is owned by Wizards of the Coast, most of it coming from 4th edition D&D. The female corsair and mindflayer nautiloid ships are from the Spidermoon article originally published in the Piazo magazine.

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