Space Ark

[Kislath]

Imagine a VERY highly developed world... that died when it's sun went nova.

Before the world met it's doom, the people constructed a HUGE ark of a spaceship, using pretty much every scrap of material they could salvage from their solar system. The ship is about 7,500 miles long, about 4,000 miles wide, and about 2000 miles tall.
Deep within it are several enclosed environmental eco-decks, each about 5,500 miles long and 3000 miles wide, and spaced about 50 miles apart. There are 30 of them. Huge artificial light are suspended above each deck, hanging from the deck above.
Artificial gravity is set to planetary norm. The atmosphere was brought in from the neighboring gas giants, filtered, purified, and the useful parts pumped into the ship. Same for the water and soil.
It is possible to just barely see the underside of the deck above, but it's appearance has been disguised.

Did you see the movie, The Truman Show, in which a guy lived his whole life in an artificial environment and didn't know it?
Well, we now have a huge ship full of civilizations who have been in this artificial environment for millennia, and today have no idea. They not only don't know they are in a ship, they don't even know that there are 29 more decks like theirs on this ship. 29 other entire civilizations they don't even know exist.

I'm thinking there is a ship's crew who DO know what is going on, and they watch everything while they've been piloting this vessel for ages in a search for a suitable new planet to colonize.
One problem-- the bio-space aboard the ship is so much larger than the surface of any such viable planet that colonization would be a major downgrade. That wouldn't have been a problem in the early years, but the search has taken too long, and now that a suitable world has finally been found, the problem of what to do has arisen. They can't just stay aboard forever, and they can't all fit on this new world without being miserable.

Whatever will they do?

I was thinking about something along the lines of a party who somehow found the doorway out of their home deck one day, and set off on an adventure the like of which they never imagined.

Aside from that, that's really all I have.
The setting could be pretty much anything while inside an eco-deck. D&D-ish, wild west-ish, modern day-ish, sci-fi-ish..whatever.
It's entirely feasible that there be quite a bit of variation among decks, too.
I'm not sure if magic has a place in it, but I guess I don't see why not.

I also suppose that there should be some old legends that nobody believes anymore, and some universal constants throughout most of those legends.

Well, playgrounders.. have at it!

[dylanh043]

very nice I once did a pathfinder campaign were everything took place within a dungeon. Objective was to get to the end but every time they went deeper to another level it's environment and cultures and civilizations were different. It allowed me to create any kind of locale I wanted for the players that i wanted. So very similar to your setting.

But truly I like the SciFi aspect of your setting I think it could lead to some pretty awesome adventures.

[Geordnet]

Well, the very first thing I thought of is: this reminds me of Larry Niven's Ringworld. Only, I like his ideas better...

But we can fix that.


The most important thing I can tell you is that you should use harder Sci-Fi.

Why? Well, simply because this story is well-suited for it. The #1 reason why people don't write hard sci-fi more often is because of the lightspeed barrier, which limits practical interstellar vessels to massive generational ships... Like this one here. So making this setting more scientifically plausible is an easy way to make it stand out from 90% of everything else.


So, what does that imply? Well, first off the artificial gravity generators are out. But that's no problem for our intrepid engineers; all they need to do is spin the ship for gravity instead! Have the basic structure of the ship be a "cigar shape", and people can live on the inside of the hull. Make it big enough, and you wouldn't even need to seal off the ends or put a roof on the bio-decks - centrifugal force alone may be enough to keep the atmosphere in. (However, you seem to be looking for something much smaller than that...)

Either way though, we don't need to live in the center. So what should we put there instead? Well, how about an artificial sun? Unfortunately your ship's far too small for a literal (miniaturized) star, but we have other options. I'll get to those in a bit, though; first we need to know where the fuel's coming from.

Well, we've got a hole in the front along with a hole in the rear... Seems to me like it's perfect for a Bussard Ramjet. (A rocket that scoops up intersteller hydrogen for fuel.) In fact, if you use a magnetic scoop it can double as protection from cosmic rays. (Also, we may want to make it reversible, so as to make it easier to slow the ship down. Assuming it was intended to ever slow down...)

Okay, now we have fuel. What do we do with it? I see two broad options. The first is to stick to convention, and use it for fusion. With this size and shape of ship, it'd probably be based on multiple fusion cells running in series along the length of the ship, rather than a single core. The alternative is to take a more novel approach, like dropping it into an artificial black hole, converting half of it to antimatter, or something even more outlandish.

Although, in the end you might not need to specify what happens in the core. If the knowledge has been lost to time, you'll never need to explain how it works even in broad strokes. (To the characters, at least...) So, let's just say it's "Fusion" and leave it at that. The real important thing to take away here is that the light in the sky will more likely be a bar than a circle.

Anyways, so here's a diagram of everything I've said so far:

Spoiler

Show

(Not depicted: the magnetic field lines forming the funnel and radiation shielding.)

Notice how the living space makes sort of a bow shape? I'm thinking now that the whole ship would have the general topology of mountains towards the ends, and water towards the middle. They'd probably need some sort of auto-dredging system like in Ringworld to keep erosion from collecting everything in the middle, too...

---

1

Now it's time to figure out what's inside this ship you have, and what might any adventurers do.


I for one prefer the idea that this ship has been voyaging for so long that records of a time before they left their homeworld have long since faded from memory. But that might just be me taking yet another cue from Ringworld.


You mentioned a "portal back home", and as it turns out there's actually a way to do that with hard sci-fi. If the makers of the ship brought along one end of an artificial wormhole, and left the other end back home, then relativity would mean that the "world" end would age much faster than the "ship" end - fast enough that their world may have fully recovered, even from total lifelessness.


Other than that... I'm not sure, actually. You've got all the problems of Ringworld, without the benefits of its massive size.

Some form of "magic" (not magitek) may be able to add an interesting spin on things, though. Maybe secrets long forgotten (and best forgotten) were rediscovered by the descendants of the original engineers? Perhaps hidden amongst the masses of refugees were a few practitioners of ancient traditions, whom finally saw their opportunity to topple the "illuminated" establishment for good? Or what if the ship encountered some entity in the void, some Thing That Should Not Be? Whatever the case, it needs to be subtle: anything flashy will ruin the hard sci-fi tone.

It's up to you; I've used up my creative juices for now.

[Kislath]

Heh. I was specifically trying to avoid any Ringworld similarities, hence the artificial gravity. It seems to me that a civilization thousands of years ahead of ours could have figured out the relationship between gravity and magnetism and created gravity. The sheer mass of the ship should exert some natural gravity as well, so they might not have to make as much.

Portal back home? I didn't mention anything like that, but carrying one end of a wormhole generator aboard is pretty cool.

The other stuff you said was all really good stuff.

Okay, I can see an amalgam of the two working well. One of the things I wanted was a clear separation of civilizations that didn't know about each other. A ringworld/dysonsphere kind of thing would have people running into each other.

So.. instead of stacking them vertically, how about we put the sealed enviro-decks around the inner hull, surrounding & facing the huge arc-light sun? It would be a similar arrangement to what you said, but without any need for a bunch of mountains to keep them separated.

The arc-light sun would have a huge revolving shutter around it, rotating to keep half the decks dark and half lit at any given time, and the speed would be adjustable to provide longer/shorter days & nights by season.

Oh! Some of the decks would be near the ends of the ship where the angle of the sun's rays would be very indirect, blocked by the apparatus that housed the arc-light, and the result would be polar decks. In fact, the position of each deck along the length of the ship would give it a climate.

WAIT! Carrying this even further, the shutter could instead be a bit more complicated, having adjustable slots in it to regulate climates and seasons within each individual deck! Or at least each row of decks. During the year these slots would lengthen or shorten to control light intensity along the lengths of the decks, giving them seasonal changes as well as climate differentiation within each one.

Yeah. That works. The gravity could even go back to being centrifugal. I kind of like the idea of the biodecks area rotating within the ship, like a huge clothes dryer, instead of having the whole ship spinning.

The gravity in the "bridge crew" area of the ship, though.. It would either need it's own separate rotating environment or actually have artificial graviton arrays.

The space between? No gravity.
The adventurers snooping around where they don't belong would be in for a wild ride.

[sktarq]

You want the easiest solution to what to do with the 30 civ's can't fit on this planet? - Drop only a percentage (perhaps even one) of the level's inhabitants off - use local asteroids and gas giants to re-outfit and repair the ship and move to the next planet that can support life. Does kinda suck for the crew but they probably have had a few generations to think about this.

As for artificial gravity....in theory possible in a sci-fi environment-particularly if it a warping of space-time that mimics gravity more than replicates it. Keeping it consistent could be interesting. Actually if the fusion core in Geordnet's image were also connected to an art grav generation array then the living quarters could actualy be on inside part of the tube-and perhaps the same technology is use to propel the ship. "Grav-drives" are one of the few ideas about FTL transport that is being actively researched. As a fun note if the habitat levels are decked out in levels about such a plan then you have high-medium-and low grav worlds for adventures to explore.
If you keep your design as stated then one thing I'd point out is that it may well be more efficient to have the artificial sun move on the roof along the length of the environment as a "day/night" cycle. Also unless you are expecting your characters to be using advanced tech then you have new set of issues of why the civs in each environment don't know about each other etc. Perhaps they all maintained their technological advanced lifestyle and communicated continuously between each level when they started but there was some kind of civil war that led to each level collapsing to various primitive technological levels by the end (anywhere between stone+iron ages for example) but at it's height led the crew to be scarred of the entire ship's safety and closed off all the levels from each other and the non environment levels. Thus each level now re-created their society from the rubble in different ways-even having different evolutionary pressures in some levels.

[The Grue]

The gravity in the "bridge crew" area of the ship, though.. It would either need it's own separate rotating environment or actually have artificial graviton arrays.

Why would the command area need gravity?

[Draconi Redfir]

I’m afraid i don't have an answer to your question, but i did have an idea much similar to this years ago.

it was while i was on a road trip down to the states, we had a stop at a beach, which i discovered was covered in hermit crabs, though i didn't know what they were at the time, they looked like aliens. Eventually i slowly started putting together a basic story idea. There is a massive ship in space that's getting closer to earth, slowly swapping it's organisms one by one with those on earth, the yeti, the Sasquatch, the platypus, all alien organisms from this ship, swapped with similar creatures that have since been thought extinct. When the last native species has been swapped, the new inhabitants of the planet live out their lives on the planet, while the ship moves on to another life-covered planet, it's interior slowly changing over the course of the trip to match the environment of the new planet, causing the new inhabitants to slowly evolve to adapt to these conditions and survive on the new planet that could indeed have a vastly different atmosphere. Meanwhile the sentiant inhabitents need to make due with what they have, stone would be unavailible, as would be any metal that wasn't somehow ripped from the hull of the ship itself. so technology would be pretty limited to leather, bone, and wood.


it did only have one bio-deck that was just massive in all directions, including at least one ocean area for whales and fish and the like. and it wasn't so much an "ark" as it was a ship designed to carry species from one planet to the next and repeat for some reason.

[genmoose]

This idea has a lot of promise. Rather than getting into the technology of the ship let me explore a few ideas about plot and what may make for a fun adventure.

One of the issues I see is that if you want your players to 'adventure' between decks then you need to have some significant open space. But that doesn't make sense for a refugee ship. Why build so much open area so that each 'deck' appeared natural when you're trying desperately to save a civilization? Even if you were planning for a very long journey (1000's of years) I'd think you'd build something more like the Axiom from Wall-E than a traveling Ringworld.


I really like the idea so let's try to figure out a fun 'explanation' that would allow for some plot.

1. When the ship leaves it is packed with people, but shortly into the trip a very deadly disease breaks out in the tight quarters. Billions die and to avoid infection the survivors try to isolate themselves into small groups with as much distance between themselves as possible. The scattering is sudden and ill prepared without a good 'end game' plan. The survivors don't know if the disease has run it's course or if it's still out there. Fear keeps them bottled up. Years blur into decades and into centuries. Knowledge is lost but there is still a fear that 'out there' is dangerous. Over time isolated pockets start to trade and communicate but that fear keeps exploration limited and does not cross 'decks'. Eventually for one reason or another the party does make that jump and starts the adventure.

This kills the idea of a massive civilization that can't fit on a normal planet but there are other ways to go. Perhaps in the isolation the different cultures grew so far apart they are almost unrecognizable to each other and to the engineers still controlling the ship. [the disease might have caused subtle mutations that develop into new 'races'] The engineers see all the survivors as mutants and are not sure who is worthy to settle in the new found homeworld. These engineers may play puppet master in causing conflict to 'test' the different decks to see who measures up to the standards (or their remembered standards) of the original refugees.

If you go with an idea thrown out above (the control areas have no gravity) then the engineers could have become something very inhuman. Combine that with perhaps some leaking radiation from the drive system and they could be unrecognizable, which would explain why they keep themselves hidden.

2. Another variation, if you don’t like the disease idea, is that the builders got their time estimates wrong. They built this huge ship but didn’t leave enough time to get everyone loaded. The ship ends up leaving with only a small percentage of its planned cargo in order to avoid being lost in the cataclysm. In the chaos the refugees are scattered around the huge ship and left to fend for themselves.

As for magic, I think you could go with a few different ideas. On one hand you can use poorly understood magitek, which would basically be magic through the use of various artifacts and those with the knowledge to kind of use them.

Another approach could be latent nanotech. Perhaps a portion of the population received nanobots to either help with diseases (should have been eventually removed) or perform certain job functions. They were supposed to perform a targeted function with monitoring and oversight but with the chaos of the evacuation they were forgotten. Over time these bots were passed from parent to child and their programming expanded to allow for some fantastic feats they were never intended for.

[Draconi Redfir]

an ide for mgic; Perhaps the ship uses some kind of strange spacefuel or something that while harmless, has leaked into a few of the habitaition decks. the higher the concitraition of this stuff in the air, the more strange stuff can happen. people eventually learned to manipulate it, allowing them to create fireballs, levitate, maybe even turn invisible, while other decks got very low ammounts or even none of the stuff at all. this could allow for a range of different ettings, from high-magic to low-magic to no-magic, with the player's abilities changing as a result as they move from deck to deck.

[Jimlad]

I Read both ideas posted so far, but I don't like ether of them. So I want to make my own ideas.

1. What if the door was opened by some power outage. Think about a power outage in a ship like this. Wait a second think about a power outage on a ship like this, all that would happen is gravity would fail, lights would fail, and doors might not open, air would be fine with so many plants. So... Let's see, that might make this a mission for getting power back, (Requiring a fusion restart if lights are out) and a part of that goal might also be to not scare all the other civilizations.

2. Well, the door unlocked... Why? And why is there this path that it looks like we should go down? Something so it all looks planed. Could even have something such that it looks like the people who first made it made all this, a path for you, the door opening at just the right time, a few trapdoors opening saving you. Something so it seems like the people who made it could see the future.

I'll think more later.

[Alexkubel]

actualy due to momentium I recon Gravity Wouldn't fail

[Jimlad]

actualy due to momentium I recon Gravity Wouldn't fail

Depends on how gravity's done. If it's being added by a device, (Spinner, or artificial) then it would die off fairly soon. If the whole ship is spinning then it'll still have gravity.

[Kislath]

Jimlad, your avatar pic looks very much like the ship we're envisioning! A little rounder, but the core is cylindrical.

Okay, how about this--- the engineers weren't content with designing just the ship. They wanted to redesign their species to make themselves better able to adapt to whatever world they finally found. Alas, they had no idea what to expect out there in the wild black yonder, so this resulted in... experimentation.

Like any experimenters, they developed a detachment to their subjects, hence the culture of non-fraternization. Over the millennia this got twisted into something somewhat peverse.

It could also explain the different biodecks-- each one houses another experiment or series of experiments. This could have given rise to the various races, and monkeying around with people's brains might have given them psionic powers that mimic magic.
( maybe they're kind of weak as psionic powers go on their own, but using various foci like materials and verbal/somatic components they can be made much stronger? )

Along the way, it makes sense that there may have been a few catastrophes resulting in tragic loss. Maybe an entire biodeck got wiped out? Maybe the experiments got a little out of hand here and there, resulting in horrid monsters or diseases?

Maybe the deck our adventurers call home has suffered a malfunction, as suggested above, leading them out into the bigger ship?

Hey! Maybe an old legend suggests some sort of supreme holy temple of some sort where the Gods can be petitioned for assistance? It could be a control room or something, or a communication center.

Alien abductions / visits from the Gods--
depending on how each culture looked at it, the occasional rare visit by the ship's crew could be seen as something amazing.

D'OH!
Clerical magic. How to do that?
I would Imagine that the ship's crew wouldn't have much interest in the daily lives of the individual people, and while they probably have ways of listening in, and can possibly perform a few feats remotely, I tend to doubt that they would.
I suppose that they could possibly use Holy Orders and clerics as a way to keep a loose leash on the people, handy for those times when it's necessary to interact with them. Clerics might have to undergo some sacred holy rite which involves implanting them with some sort of chip or device which allows an interface with the ship's crew.
Maybe the powers of healing and such that we're uses to seeing clerics have are just as psionically based as the other magic, but more specialized somehow.

I guess we wouldn't be able to have the full range of spells, thaumaturgical or clerical, that we're used to seeing in D&D. We could have a lot of them, but some just wouldn't be able to work.

[The Grue]

D'OH!
Clerical magic. How to do that?
I would Imagine that the ship's crew wouldn't have much interest in the daily lives of the individual people, and while they probably have ways of listening in, and can possibly perform a few feats remotely, I tend to doubt that they would.
I suppose that they could possibly use Holy Orders and clerics as a way to keep a loose leash on the people, handy for those times when it's necessary to interact with them. Clerics might have to undergo some sacred holy rite which involves implanting them with some sort of chip or device which allows an interface with the ship's crew.
Maybe the powers of healing and such that we're uses to seeing clerics have are just as psionically based as the other magic, but more specialized somehow.

One possibility is that "divine magic" is actually a semi-forgotten means of tapping into the ship's verbal command system. The verbal component of, say, Control Weather might include a specific command in a forgotten language to the life support subsystem to adjust the local atmospheric conditions; the somatic component manipulating a holographic control pad that no longer renders. Divine focuses might be command staff keycards or ID badges.

[Alexkubel]

surely there has to a way to have hats fit in here somehow?
I don't know maybe the comms are built into the cap, I don't know but I want to have clerics in silly hats.

[Kislath]

Grue, that's great! It makes sense, kind of like when someone on a Star Trek holodeck issues verbal commands to the computer.

Silly hats?
Yeah, okay, hats can work fine.

Hey, Cardinal.. nize hat!

[Jimlad]

So, have we decided on how the magic will work for these guys? There are ideas, but I haven't seen an end decision.
We've got priest spells.
We've got 2 methods of gravity, most likely will be a spinner in the middle for the Bio-decks.
Races will be minor mutations and some experiments.
Plot will be made by players.
End goal, we don't have.
It'll also be like plot, but there can be variants.
I can see 2 endings. First, get power back. Second, find a suitable world to live on.
Any other ideas anyone?

[Kislath]

I guess I'm leaning toward magic really being psionic in nature, but the people don't really quite understand that.

As for some plot, I kind of like the idea that the ship's crew is trying to think up a way to eliminate most of the people in the biodecks so that the remainder will fit on the new planet. They want the very best sorts of people for the new world, who will represent the best chance at success for the new civilization they are about to create.
Naturally, our adventurers aren't too keen on the idea.

There should be a complication preventing everyone from just staying aboard the ship, too, such as the ship itself is on it's last legs ( thrusters? ) and will soon suffer catastrophic degradation.

So... figure out how to fix the ship, engage in a eugenics program of epic scale, let everyone mass-colonize and ruin the new planet, or sit around and die?

[Jimlad]

I guess I'm leaning toward magic really being psionic in nature, but the people don't really quite understand that.

As for some plot, I kind of like the idea that the ship's crew is trying to think up a way to eliminate most of the people in the biodecks so that the remainder will fit on the new planet. They want the very best sorts of people for the new world, who will represent the best chance at success for the new civilization they are about to create.
Naturally, our adventurers aren't too keen on the idea.

There should be a complication preventing everyone from just staying aboard the ship, too, such as the ship itself is on it's last legs ( thrusters? ) and will soon suffer catastrophic degradation.

So... figure out how to fix the ship, engage in a eugenics program of epic scale, let everyone mass-colonize and ruin the new planet, or sit around and die?

I guess I forgot to reply to this, anyway.
Okay, so we've got basics of magic.
Second part. AHAHAHAHAHAHhahahahah, Oh, you think that the players wouldn't like to see half the crew killed. hahaha.. But yeah, the DM can find a way to make sure they want to whole ship alive. But I think magic should maybe be that they got technology, so they ignored magic. And lost it. And the mutations, lack of technology, and experiments all work together to bring magic back.

[Kislath]

I reckon if the Overseers have slated the adventurer's home biodeck for destruction, they might care, at least a little.

Magic. Ugh.
What we need is a good sensible way for "magic" to exist in such a high-tech setting.

Why have it at all?
Because my original plan was to start the campaign as a normal game under more or less normal rules, with the players and characters having no idea what's really happening. Let them adventure normally for awhile, level up, do awesome stuff, and THEN let them make a curious discovery. A little epic exploration would reveal the truth to them, little by little.

[Draconi Redfir]

always my gas-leak idea, maybe the players strt in, and the first few biodecks they visit just don't have it, while some of the later ones they visit do,

[sktarq]

There should be a complication preventing everyone from just staying aboard the ship, too, such as the ship itself is on it's last legs ( thrusters? ) and will soon suffer catastrophic degradation.

So... figure out how to fix the ship, engage in a eugenics program of epic scale, let everyone mass-colonize and ruin the new planet, or sit around and die?

Simple. After a several thousand year old trip the radiation from fusion generators, interstellar travel etc is degrading the outer walls and power systems. Sure there may be another thousand year of life in them left but the next habitable system is 3300 year away. Any degradation more than 50% is enough to be a stranding effect as the next jump would probably be just as long as the one the ship just took from their home world.
Another option for arcane Magic...There were nanite colonies in the original biodecks that were psi-reactive. Basically they could make most things happen. The command systems for them were wired into original inhabitants brain structure and while many have lost this instinctual use of this region (namely sorcerers, bards etc) a few can use elaborate pneumonic to make such a command system work. Any region where you don't want magic to work-the nanite scrubbers are still in working order.

[Kislath]

Hey..yeah.. that's good stuff! It might also have a system kind of like a holodeck with the safety turned off, too. The nanites can do the detail work, while the holo-emitters handle the big stuff.
Hmmm.. maybe that was all put there as a form of entertainment ( and easy environmental maintenance ) for the long voyage, but along the way people just forgot about that and think the magic is real, since to them it might as well be.
The experiments performed on some of the people might have let some people gain a natural ability to tap into the system, negating the need for control systems or funny hats?

Yes...good stuff!

[Geordnet]

Magic. Ugh.
What we need is a good sensible way for "magic" to exist in such a high-tech setting.

Why have it at all?

Because if done right, it can be Really Cool.


But not with "High Magic" of any sort which resembles that in D&D and similar RPGs. That's why I stressed the point of no magitek so hard: if it's functionally identical to Sufficiently Advanced Technology, then it shouldn't be included.

That's why I think a sort of sinister, mysterious, and overall creepy sort of magic would be a good addition. Something which gives the sense that magic is literally Tears in the Fabric of Reality. Magic is the shadows encroaching on the flickering flame of Enlightenment, slowly wearing at the fire of Civilization, threatening to one day snuff it out...

That is a kind of magic which meshes with hard science fiction quite nicely, since it's explicitly in-universe Stuff Which Science Cannot Explain.

[Kislath]

Yeah, okay. That's good! That would work fine. Remember a movie called "Event Horizon?" That was a fine example of how high science can clash with that which it cannot explain.

[Snowyowl]

At the same time, I can't help but feel that if it's a sci-fi setting, there should be sci-fi technology in daily life. The "magic as forgotten technology" angle has been addressed already, magic in D&D sourcebooks is going for a very specific feel and it doesn't make sense to interpret it as verbal and gestural orders issued to an omnipresent AI. At least, not without making the setting a lot softer than it has potential to be.

Technological artifacts, on the other hand, are perfect for the feeling I think Geordnet is going for. Radios that let people stay in contact, construction equipment that turns out to be better weapons than anything blacksmiths can forge (welding torches, titanium saws), Siri-like information dispensers (if you can understand the language), anything with a screen makes a decent flashlight, GPS equivalents, Geiger counters, radiation suits and space suits that are incidentally pretty good armour, pill bottles with amusing effects, assorted packaging materials and gas canisters, UV lights, laser pointers, jury-rigged EMPs, ID cards that unlock the right doors and equipment, oven gloves, conveyor belts, trash compactors, and the occasional taser or tear-gas grenade that was actually meant to be used as a weapon.

Basically just look through the Space Station 13 wiki and think about how any of that tech would look to a civilisation that's forgotten about it.

[Fairy Lisa]

Oh my gosh! The sheer size of that is incredible! 16,500,000 square miles per deck! To put that in perspective, I wanted to compare it to the size of Russia, but that turned out to be too small, and then the size of the former Soviet Union, but that was also too small.

The Asian continent (largest in the world) is about 17,212,000 square miles, and is historically the most ethnically diverse on Earth and has a population of over 4.1B people at the present. You have around 30 Asias to play with, give or take a million square miles each.

And the crew! Is it a crew or a whole new ethnic group that developed in parallel to whatever civilizations your 30 Asias developed during the voyage?!

You talk about a “civilization” one per deck (30 decks!), but you could have multiple civilizations and cross-deck civilizations and everything! This is a setting you could reuse in campaigns over and over again and never run out of room to grow. Is this a Space Ark or another planet?

[Snowyowl]

Is this a Space Ark or another planet?

It's bigger than another planet, with none of the difficulties of terraforming - I'm not really sure why they'd want to disembark when they arrive. It'd be like taking a luxury ferry to visit a ten-meter rock in the middle of the ocean.

Unless they were planning to build Culture-style Orbitals in the new star system. And why not - that's just under Kardashev 2, as is the planet-sized space ark. At least the power levels are consistent.

[Draconi Redfir]

problem with space arcs vs habital planets is that space arcs need technology and effort in order to maintain it's habitat, whereas planets just kind of have it naturally. as well spaceships of any kind are essentually large air bubbles surrounded in tin foil in a vaccume, so even the smallest of holes can lead to the death of everything aboard, not a problem on a planet.

As well, if using a space arc to colonize a planet, you could very well canibalize the space ark itself and use it's own resources to improve the planet, you could go centuries without needing to dig a single hole on the planet just by mining the ship itself for what you need. Though admitedly that would mean it would be more trouble to leave the planet again should something bad happen.

[Fairy Lisa]

I thought about it some more and you could comfortably support up to 4B people on each deck. Estimates for the size of the Asian continent also include the vastly underpopulated Asian part of Russia, and most of those 4.1B live in either China or India despite Asia being much much larger than that. Presumably deserts will also not be an issue given each biodeck would have been designed to actually support people rather than leave them starving out in the equivalent of the Gobi Desert if they got lost, so actually including any deserts in any of the artificial environments would have been wasteful.

So productively, maybe even up to 6 or 8B people per deck using only non-magical agricultural technology that’s no more advanced than what we have on present day Earth (we grow enough food to feed about 9B people, we have 7B+, and people still starve because of waste), and if the baseline was about 2B people per deck (maybe that was what it started with to support population growth), we’re looking at between 60B and 240B people on the ship at any given time.

If you go to Wolfram Alpha and ask for an estimate for the number of humans who have ever lived, it returns date from 2011 from the Population Reference Bureau, who estimate it at about 107.6B people at the time, assuming modern Homo sapiens appeared around 50,000BC.

So yeah, huge! Easily enough space to encompass every ethnic group that ever lived twice and then some!

EDIT: Oh I’m sorry, did I say every ethnic group? I clearly meant every PERSON that ever lived.