Mothership Planet Generation

From the NASA image library

This is based on some of the tables Sean is working on for the Warden's Guide, which he very graciously shared with me on Discord.

These tables are meant to be more easily usable than the other hard-science generators I have found out there: I think it's come out quite nicely, but I had to resist my urge to go into scientific detail as if I am organizing Pokemon.

An important note: if a planet has people on it, it is going to have orbital infrastructure. It's part and parcel for the colonization.

It is always easier to build in orbit than on a planet.

0. A Note About Stars

The star your planets will orbit will almost certainly be an M, K, or G class star. This is, in the grand scheme of things, not particularly important when playing Mothership.

If you want a binary system, this is easy: if the stars are close together, roll up a single system and get rid of anything in epistellar orbit. If far away, roll up two systems, get rid of the outer orbits.

1. Roll d100 for System Class (d10) and Orbits (d%)

A system's classification is dependent on a combined reading of population (Low / High), economic standing (Poor / Strong), and governance (Independent / Company).

1. Low population / Weak economy / Independent
2. Low population / Weak economy / Company
3. High population / Weak economy / Independent
4. High population / Weak economy / Company
5. Low population / Strong economy / Independent
6. Low population / Strong economy / Company
7. High population / Strong economy / Independent
8. High population / Strong economy / Company
9. Roll again: there is a sizable anarchist population in the system.
10. Roll again: there are active Celestials in the system.

Alternatively, you can roll on this handy aesthetic reference table.

1. Alien
2. SCP Foundation
3. Borderlands
4. Transmetropolitan  
5. Cowboy Bebop
6. Prospect
7. Kill Six Billion Demons
8. Mass Effect
9. Warframe
10. Quantum Thief 

Each system is abstracted to ten orbits. The % die on this roll determines how many of them have a major body in them, but we'll get specific in the next step.

Orbits have temperature zones, which add extra factors to whatever is there. The standard zones are epistellar (close to the star), inner (liquid surface water possible) and outer (very, very cold).

The default arrangement is orbits 1-2 are epistellar, 3-5 are inner, and 6-10 are outer. This can be adjusted as one sees fit (M-class stars have such tiny orbits that they might be 1-4 epistellar, 5-7 inner, 8-10 outer, for example)

3. Roll d100 for each Filled Orbit

These classifications are primarily by mass. If you want to go further down the rabbit hole of specificity, I highly suggest checking out the Orion's Arm page on world classification.

1-10: Empty - Looks like a false positive on the preliminary readings.
11-25: Asteroid belt - 50% chance of a dwarf planet here, explodes on a 10.
26-45: Dwarf planet - Too small to hold an atmosphere. Ceres, Pluto, the Galilean moons.
46-60: Terrestrial planet - Venus, Earth, Mars. Come in these varieties.

• 1-25: Rockball - No atmosphere to speak of. may be hot or cold. Mercury.
• 26-50: Arid - Trace atmosphere. May be hot or cold. Mercury, Mars.
• 51-55: Gaian - Oceans of liquid water and sustainable atmosphere. Earth. Turns Icy in the outer system.
• 56-75: Hothouse - Very thick, very hot atmosphere. Venus.
• 76-80: Water-world - Mostly or completely covered in ocean. Turns Icy in the outer system.
• 81-100: Icy - An ice and rock mix, or a shell surrounding a subglacial sea. May have an atmosphere. Europa, Titan. Turns rockball or arid in the epistellar zone. 50% chance of being a water-world in the Inner zone.

61-80 Superterran - Bigger than Earth, smaller than Neptune. Very high surface gravity and typically superdense atmospheres. Surface settlement is a really bad idea. 25% chance of being a water-world.
81-90: Gas dwarf - Overlaps with the high end of superterrans. Neptune and Uranus. d10-5 moons of note.
91-100: Gas giant - Mostly hydrogen and helium. Jupiter and Saturn. d10-3 moons of note.


Epistellar worlds have a 50% chance of being tidally locked. Terrestrial and superterran worlds have a 50% of losing their atmospheres to radiation.
 
Outer system terrestrial worlds have a 25% chance possess an ammonia atmosphere.

If you roll doubles on orbits, you may choose:

• Reroll
• Move to next nearest orbit
• Is a major moon of the previous world (must be at least 1 size category smaller)

Add moons at your discretion.

4. Roll 2d100 for Planet Tags

1. Eccentric orbit - Planet travels both very close to and very far away from its star.
2. Eccentric axis - Severe axial tilt means extreme seasonal variation.
3. Tectonically volatile - Extreme volcanism regularly reshapes the landscape.
4. Native biosphere - A healthy global ecology has evolved here.
5. Imported biosphere - Earth-based life has taken hold on the world.
6. Neogenic biosphere - All the life on the planet was custom-made to fit the environment.
7. Corporate demesne - A corporate dynasty controls this planet as part of their private holdings.
8. Lost colony - The original settlement is long-gone, without good explanation.
9. Religious revival - What was old is new again, with fire and brimstone and fervor.
10. End of hostilities - A tenuous peace settles as the warring factions lay down their arms.
11. Cultural reserve - The world has been set aside for the preservation of a specific cultural group that would have otherwise faded out.
12. Running the asylum - The normal leadership was ousted but no one has been able to take charge.
13. Political upheaval - Destabilization has left everyone anxious for the future.
14. Breakthrough technology - Everyone wants their hands on it.
15. Rust belt colony - The founding Company has abandoned this world for cheaper labor elsewhere.
16. Metahuman world - A notable clade of metahumans is the majority population.
17. Uplift world - Planet is majority inhabited and run by uplifts.
18. Machine world - Planet is home to a collective of AI-4 dataminds.
19. Apocalypse recovery - A catastrophic event came close to wiping out the colony
20. Open warfare - Tensions boiled over and major powers have mobilized.
21. High gravity - The planet has an above-average mass for its size.
22. Low gravity - the planet has a below-average mass for its size.
23. Radiation flares - The parent star regularly spits out waves of radiation that will scour away unprotected atmospheres and cook unprotected organisms.
24. Quarantine - An outside party has declared that no one and nothing is to leave the planet.
25. Android rights - AI and uploads have significantly more rights here than the corporate average.
26. Indentured population -The entire colonist population is indebted to the same company.
27. Recent impact - A stray asteroid violently reshaped the surface of this planet within
28. New colony - The first settlements are less than a decade old.
29. Gate hub - There are multiple hyperspace gates stationed in this system.
30. Paleontology dig - Alien fossils! Nothing cooler than that!
31. Gone fallow - The colony was abandoned for a time
32. Xenos! - There is a very notable instance of alien life on the planet, native or otherwise.
33. Primordial soup - The planet contains all the right elements for the formation of life, but it has yet to emerge.
34. Colony collapse syndrome - The colony has begun on the inextricable path to complete social collapse.
35. Isolated - The colony was cut off from the rest of civilization for decades, potentially centuries.
36. Celestial ruins - The Celestials left behind cyclopean structures of indistinct purpose across, above, or around the planet.
37. Hyperspatial anomaly - Something has gotten utterly fucked. There will be a DMZ.
38. Geological mystery - Certain unique features of the planet have yet to be adequately studied or explained.
39. Binary companion - The planet has a twin of similar mass.
40. Anarchist stronghold - Planet is home to either a major community or is entirely anarchist.
41. Celestial influence - The planet and its inhabitants have been shaped by members of a Celestial house.
42. Luxury good - Planet is the sole provider of a highly-desired exotic good.
43. Algowar - A powerful but non-aware AI has begun a behavior loop that will kill the population if left unchecked.
44. Pleasure world - Designated a luxury retreat for company elite.
45. Sole proprietor - Planet is owned by a single individual rather than a company.
46. Unexplored surface -For whatever reason, the surface has never been investigated beyond a few preliminary probes.
47. Legendary history - An event known across human space occurred here in the now-distant past.
48. Economic rivalry - The planet is in a severe trade war with a nearby world.
49. Open immigration - The planetary government is very welcoming to visitors.
50. Closed border - The planetary government is incredibly strict on interplanetary visitors.
51. Paraterraforming - The development of a worldshell is continuing nicely.
52. Punchline - The inhabitants of this planet are widely mocked, rightly or otherwise.
53. Dreamland simulation - The physical colony is sparse and minimalist - the real colony is the simulation overlapping it.
54. Zoo - Planet has been set aside as a reserve for rare and endangered animals.
55. WIP metahuman clade - A widescale metahuman development project is underway, with the first few generations already active.
56. Fringe religion - A splinter of a mainstream religion holds sway here.
57. Breakaway colony - Founded by political separatists from a nearby world.
58. Nanocloud cover - The atmosphere is seeded with an omnipresent nanotech cloud.
59. Cyberdemocracy moot - Planet has a functioning cyberdemocracy government.
60. Autarchy - Planet is ruled by one or more Venusian-style autarchs.
61. Tourist destination - Visitors from all over human space come to see the sights, visit the locals and go to overpriced restaurants.
62. Monastery - Planet is home to a cloistered religious order.
63. Refugee influx - Those fleeing from instability or catastrophe are arriving in great numbers.
64. Strange moon - Scientists are constantly sending missions there.
65. Getting better - The economy is flourishing, things are stable, life is safe and prosperous.
66. Getting worse - The economy is floundering, government's unstable, greater dangers are looming.
67. Cultural powerhouse - This planet is the center of attention for lightyears around.
68. Neutral territory - The planet is used as a meeting ground for warring parties from other systems.
69. Mass exodus - Whoever is able to flee the planet is doing so.
70. Government-in-exile - Colony was founded by the deposed leadership of a nearby world.
71. Penal colony - Originally settled by criminals exiled by their parent company or government.
72. Nuclear fallout - Might have been an accident, might have been an exchange, the atmosphere is full of the stuff.
73. Resource lottery - Luxuries and opportunities are randomly selected.
74. Subterrene - The entire colony is underground and going deeper.
75. Unusual gender roles - This is in a setting with easily-available sex-changes, exowombs, and zygote fusion, mind you.
76. Potluck - Colony was deliberately founded by varied clades and cultures working together.
77. Mystery founding - No one, even the colonists, knows when and why it was founded.
78. Perpetually petty - The planetary government has a chip on their shoulder and paper-thin skin.
79. Revisionist records - The planet's government has successfully rewritten not only its own history, but that of human space.
80. Forgotten - The planet has been wiped from the records of most of the outside world.
81. Hidden Library - A secret repository of knowledge, hidden away from outside forces.
82. Askew - Everything is strange here, and the locals go about their business as if it is perfectly normal.
83. Linked smartpets - Everyone has a smart dog companion. Everyone!
84. Symbiotic cordyceps - Well this is terrifying. Pack a filter.
85. World of immortals - None of the locals can die, which has led them to be quite dismissive of outsiders, mortals, and children.
86. Poisonous biosphere - Life on this planet is, moreso than the average, inimical to Terran biochemistry.
87. Reincarnation economy - When someone dies, a stored copy is embodied for the amount of time they had stored up in their previous life.
88. Afterlife servers - Vast simulations are prepared for citizens for their single permitted mind-upload upon their death.
89. Tax haven - Interplanetary corporations use this planet to dodge their home system rules.
90. Mysterious signal - World received a clearly-artificial radio signal from an unknown source, and it's yet to be deciphered.
91. Epidemic - A virulent disease has been spreading wildly, no cure in sight.
92. Roadside picnic - The planet isn't really a colony, just a place for people to stop on longer
93. Military outpost - Colony founded purely for the military interests of another world.
94. Tenacious - The population has a reputation for resisting and enduring repeated disasters.
95. Santa Claus machine - A broken printer system and dumb AI has flooded the economy with goods, wanted and otherwise.
96. Vile vizier - The company dynasty is taking questionable advice from their consultant.
97. Meld-Marriages - It is custom for pairings to intermingle their cyberbrains.
98. Charismatic faction leader - Came out of seemingly nowhere, major factions now troubled.
99. Blacksite - The colony was built off the record for secretive purposes.
100. Godhead -There is an honest-to-stars Celestials physically present, right here, right now.

5. Roll d50 for Planet Hook

1. The revolution has begun! The executioners are overworked and understaffed.
2. Grievous computer error converted all digital text into Voynich script.
3. Hippos imported for meat. Still an awful idea designed by idiots. Still funny.
4. A decaying billboard at the spaceport reads "Have You Seen the Yellow Sign?"
5. You don't recall everyone being this fat the last time you were here.
6. The empress has declared a crusade fleet to retake Earth, here called Palatine.
7. Invasive, trash-eating ibises are everywhere; local Thoth cultists won't budge.
8. The Black-Nail Crew just introduced a new variant of OK to the black market.
9. Freak landslide buried an entire settlement.
10. The wet season has triggered a mushroom overgrowth.
11. Cult of 1000-Eyed Wa is emerging from its hibernation cycle.
12. Deliberately alienating architecture triggers anxiety and headaches.
13. Recently bought and rebranded by a pharmaceutical company.
14. "Please avoid taunting servitors of the Red Ziggurat: they are our guests."
15. Neogenic sphinxes lunge about; honored, intellectual, regal.
16. Facial recognition tech has triggered asymmetric fashion fads.
17. Colony is being torn down for ritual rebuilding.
18. Population decanted as adults, working of their debts to be remade as children.
19. Redoubters have arrived with their black pyramids, authorities are furious. 
20. Upcoming marriage between scion sons of Gezo Heavy Industries and ISOtech
21. Population preparing for non-networked mass-upload.
22. Colony gripped by a wave of antisex, antinatal ideology.
23. Rival colony ship, delayed by decades, arrives without warning in orbit.
24. Entire population goes braindead for three minutes before revived by their implants.
25. Expired gene patents have lead to widespread food shortages
26. Immortal corporate scion with martyr complex playing at Jesus, ineffectually.
27. "Cambion" births coming into fashion.
28. Local lifeforms are emerging from a centuries-long hibernation.
29. Swarms of smart-lemurs running maintenance have taken control of habitat.
30. Major interplanetary trade deal fell through; unions sweeping into to vacuum.
31. Disappearance of net personality under mysterious circumstances.
32. Assassination of media mogul already embroiled in scandal.
33. Genocide against a minority population is underway.
34. Automated content flaggers have taken down most of the net in a matter of months.
35. "What's the worry? It's just the Jubilee Squid Festival! People very rarely die."
36. War machines hacked by anarchist satire collective.
37. Uplifted corvids have replaced most of the internet. More accurate.
38. The local machine cultists have elected a controversial new technopontifex.
39. New art style is all skeletons, all the time.
40. A omnipresent RPG overlay has been applied to everyday life
41. A minor rogue AI has been placing 'curses' on people via social media.
42. The Office of New Religious Movements has been overwhelmed of late. Too many cults!
43. Everything is either loot boxes or battle passes now. Even groceries.
44. Someone has some god-damn original NASA tech on display.
45. Someone thought it'd be a great idea to make mosquito-headed ghouls and release them in the vents for a laugh.
46. This red-faced figure keeps appearing in random videos and photos, people are getting alarmed.
47. There are rumors of a trade in illegally-made mind-copies operating out of here.
48. Some corporate scion is going around wearing sackcloth, saying he'll give away his fortune to some clever individual capable of fulfilling his three tasks.
49. The simulationist missionaries of MANA-YOOD-SUSHAI are in town.
50. You've got a new FRIEND request.

Example System

Tau Ceti was one of the more lackluster systems in the gazetteer, so let's spice that one up.

System Class: Low population, weak economy, independent, with a sizable anarchist population

Aesthetic: Alien

Orbits: 5

• Orbit 4. Terrestrial rockball (Hou Yi)
• Orbit 5. Terrestrial rockball (Chang'E)
• Orbit 7. Superterran (Zhinü with major moon Niulang)
• Orbit 8. Icy dwarf planet (Mr. Lonely)
• Orbit 10. Superterran waterworld (Helen, with major moons Paris and Meneleus)

Let's say our main settlements are on Hou Yi and Chang'E. I'll just roll for both of them.

Tags: Celestial ruins, Political upheaval

Hook: Local lifeforms emerging from hibernation

So! Tau Ceti is remarkably small and overlooked for its location, and this is for two reasons.

Reason 1 is that Celestials had rule over the place for decades before they packed up and left. Astronomers are pretty sure there used to be a few planets closer to the star that got converted into construction materials.

Both Hou Yi and Chang'E are covered in circular patterns of white, rectangular towers and deep artifical crevasses. A series of 28 braided rings, each a thousand miles in diameter and bearing a golden sheet in the center like a drum head, orbits Tau Ceti at half an AU. A black structure that is clearly a country-sized building sticks up from the brown-white surface of Mr. Lonely. Orbitals like rosary beads. There is a lotus the size of a continent floating on the upper atmosphere of Helen.

Reason 2 is that the first people to get to Tau Ceti were a second-wave anarchist collective with roots pre-expansion China, using hand-me-down corporate tech decades out of date. They were blacklisted early on by the CTA under pressure from the government of Gliese 667, and so have no one to sell their surplus to; anyone who admits they exist, let alone trades with them, gets smacked down with economic pressure from 667.

This means that the colony has struggled to expand over time, and still only consists of two small planetary settlements and a handful of orbital habitats. (There is a refueling stopover station in orbit around Helen, where passing ships tend to stop by.)

Things have taken a turn for the worse recently as recent patches to the central planning computer system have resulted in resource and work shortages. Factions are starting to form over what to do, if the small amount of resources at the colony's disposal should be put towards fixing the CPCS, finding a replacement, or trying a different method.

But it seems the Celestials are not done with Tau Ceti. Vaults in the earth and sky are opening up, revealing some form of servitor not yet before seen: a serpentine thing limbed like a centipede, a slender too-human hand at the end of each thin arm. An eyeless, bullet-shaped head. Smooth skin, black on top, white below, a thin streak of orange along the sides. A smile of V-shaped teeth. They can grow their own solar sails to coast between worlds. And those who have met them keep claiming that they were invited below the surface by the creatures, promised something that could not be named and couldn't possibly be fulfilled.


Anyone who uses this system, definitely let me know!