# Why does this one planet still have slaves?

The year is gazillion and five and humanity has spread out across the galaxy. As we expanded, empires were formed, then toppled, federations coalesced, then unraveled, feudal kingdoms cropped up and were swallowed up. In short, history has been lively.

The current situation, which has held semi-stably for a few centuries now, is one of relative peace imposed by military detente, with five huge interstellar nations dominating the economic and diplomatic arenas. Of the ever-dwindling number of still-independent worlds, most are too low-value to be noticed, but a few, conveniently located along borders between the major nations, are crafty enough (or gullible enough) to play the nations against each other to maintain their independence.

True sentient AI continues to elude researchers despite millennia of continuous research. For that reason, even though everything that can possibly be automated has been automated, but humanity at large still needs to work. People still have jobs and salaries. Scarcity and unemployment are still a thing in many places, although in most cases, things are prosperous enough to ensure that everyone has access to basic dignity and opportunities.

That said, economic and white-collar crime is rampant, and economically-motivated violent crime is as common as it has ever been. On the other hand, genocide, xenophobia and even racism are not exactly extinct, but they happen to be at an all-time low. Slavery, of course, is illegal everywhere.

Except this one planet. Here, a large percentage of the work force is involved in one particular industry as actual slaves, forced to perform their life-threatening duties under threat of whippings and beatings or outright executions. Accidents abound and are often crippling our outright fatal, but this is just a cost of doing business. The slave population is replenished by forced breeding and the occasional importation of criminal (and some times not so criminal) prisoners.

This situation has persisted for just under two centuries. Over the years, many people have looked into doing away with this situation. The problem is that, for very strong specific reasons, even with the deplorable safety record, maintaining a slave work force is the only way this planet can maintain any viability as an inhabited world. Granting freedom to the slaves would result in a critical work force shortage and subsequent shutting down of this particular industry, quickly followed by the unstoppable collapse of the planet's economy. The end result: exodus for those with the means to leave, mass starvation for the rest.

The majority of the free folk on the planet is actually unaware of the situation. (Or maybe, they are just purposely keeping themselves in the dark, or actively lying to themselves.) The full truth is known only to the slave owners and overseers, to the highest ranks of planetary government, and to a very select few top officials off-world. And to the slaves themselves, of course.

The question: Why does this one planet still have slaves? What do the slaves do that justifies their existence?

Aside: I prefer the issues to be local to the planet, but if this can't be realistically achieved, I could make this about the only way for the galaxy to obtain some critical resource instead.

• On the topic of AI, true sentience is not required to replace every human job imaginable. In fact, there's a strong argument that we couldn't even tell something we created is conscious or not. – bendl May 8 '18 at 18:05
• Frank Herbert's Dune rings a bell on the scarce resource side of your problem. Also Anne McCaffrey's Crystal Singer – EveryBitHelps May 8 '18 at 18:44
• Oh wait, you are not talking about earth, are you? – SK19 May 8 '18 at 21:59
• @JBH The questions should be the same, inasmuch as the question in the body is the "why behind the why". To clarify, the planet has slaves because otherwise it would starve. But why is that? What's so special about this planet that slavery is the only thing that can keep it afloat? Some very interesting answers, by the way, and much material to sleep on. – João Mendes May 8 '18 at 23:26
• coughthat'showtheworldworkstodaycough ...Excuse me, had something caught in my throat – thanby May 10 '18 at 12:32

Your slaves aren't legally defined as slaves to the outside universe.

Several centuries ago the initial settlers were selected as a control group of otherwise "unhealthy" or doomed citizens who were promised a scientific application of a new prolonging treatment that involved habitation in a controlled environment absent of the toxicities found in the common industrialized planets. They were relocated in mass and settled into their communities, which were effectively the same as small villages from history so far back people don't even remember what it was like to have a house made of something other than metal and concrete.

To them, this is a haven. They are given a prepared (a-la terraforming) unindustrialized planet and governed only by a subset of rules enforced by the relative inhospitality of the planet itself. A natural prison. Their work consists of crop management for food sources that require tons of land, produce enormous emissions, and are considered relatively unappealing to a lifestyle where everything is manufactured and prepared. In other words, people have forgotten how to butcher livestock.

Without getting too technical, in a future where corporations, conglomerates, and all such have grown to sizes too big to fathom, the concept of whole or natural has been lost in the feasibility of distribution and preservation to a large, interstellar network. Food has to be processed to endure any duration of shipment. But not here.

Here we have fresh food and vegetation of all varieties, grown in mass where the population, even if gorged beyond ambulation, could not possibly consume the product or even threaten its output. The citizens know they are in a controlled study and the only way to ensure their care is to fill the planet with crops, harvest, deposit in the shipment tubes, and keep on going. They are told their treatment requires huge amounts of product to extract the serum they need to live, which is a common multi-vitamin but they don't know that. Their offspring will thrive, so long as they too consume the serum. And out of fear you maintain a world of slaves.

Why is this allowed? Because business has some crooked roots. A while back some huge pharmaceutical company purchased this planet in its useless state and dropped some automated terraforming machines onto it. It took centuries to become viable, but eventually it was declared legally habitable as a class X settlement - which basically means study only. Thanks to the never ending loop holes that plague all legal systems, this planet is now wholly owned by the pharma company, who can and will use it for "study." And since it is class X, nobody really cares to dispute this. It is unfit for industrialization or settlement at this time in a universe with so many options.

As for the subjects, the first round volunteered. They were duped, so to say. Pushing notions of an illness whose only cure appears to be an environment in a low pollution atmosphere, plenty of sun, or however they chose to sell it, the people were offered some guarantee of service, plus an incentive to their living families. Ultimately a cheap expense for the company, but to the families of the sick, it was a once in a lifetime opportunity. No matter how good society gets, some will always want more. And they found them.

The sister planet is close enough for travel and is a special class designated to the ultra wealthy, or people who can afford such vacations. Contracted exclusively to the company, who owns planet X, for consumable resources. The people of the slave planet only know there is a sister planet, but don't know anything about it. In reality, the supplies harvested from the legal slave colony in abundance are sold as a premium to sister planet. A taste of real food for those who can afford it. A planet close enough where the product does not require preservation or alteration. One of the few places left in the industrialized universe where you can taste anything like it. Because of this, people tend to look away when they realize the food is a product of legal slavery. They see them as happy volunteers offered a lifestyle only read about in history. They see it from above where they don't know the truth about what happens on the surface. Plus, they can't because it's private property.

Essentially, they are slaves by definition only. Legally, they are patients of a medical study. All signed and legal, including offspring.

The company has an exclusive right to this planet for the designated contract of 70,000 earth years. Or basically forever. They made sure to lock that one down knowing the last true treasure is the simplest of things - a good hot meal that doesn't come out of a bag.

Win win.

• I like this solution. Upvoted. – Rain May 8 '18 at 22:17
• This... is interesting. Would probably fit the question better as two continents, rather than sister planets, but the concepts are the same and they are solid. +1 and I'll be mulling it over. – João Mendes May 8 '18 at 23:08
• I kind of thought of that but I figured if there was a place on the planet itself where the ultra rich could be discovered somehow it might become apparent to the slaves that they are being duped. To keep them content, they have to believe this planet and the simplicity of what they're doing is their end goal and to want for more is a figment of imagination. So to say... we covet what we see. Additionally, the resorts would boost the value of the planet and may make it a target of some legal custodial battle that ends outside the pharma's ideal situation – Kai Qing May 8 '18 at 23:24
• This sounds similar to the stars like dust by Isaac azimov... – Garret Gang May 16 '18 at 18:58

The problem is that, for very strong specific reasons, even with the deplorable safety record, maintaining a slave work force is the only way this planet can maintain any viability as an inhabited world. Granting freedom to the slaves would result in a critical work force shortage and subsequent shutting down of this particular industry, quickly followed by the unstoppable collapse of the planet's economy. The end result: exodus for those with the means to leave, mass starvation for the rest.

You are describing nowadays China, modified to be a whole planet rather than a country. Have a look at this related question:

Could a Megacity be a Penal Colony?

Now, some people may say that chinese factory workers are free to leave whenever they want. I have read about this situation in other countries, and seen it happening on my own. Here industry owners will hire the poor and uneducated to work on their farms, providing not only a salary but also food and shelter. But the food and shelter must be paid for, usually the rent of the tools used for the work as well. The wages are not enough to pay for it all, and the workers must stay and work harder, or else. By the way, we don't want to admit that such inhumane practices are still a thing in the 21st century, so the local law here calls such cases "situations analogue to slavery", but not slavery proper because that has been abolished.

A prison planet might work just the same. As long as the costs/benefits to shelter and feed slaves are more favorable than the cost/benefits of using machines or free labor for the same job, there will be slave planets. And the excuse will be a centuries-old one:

Alternatively, the population is made of the most dangerous criminals of the universe. For one reason or another they cannot be dealt with any other way, so planetary governments are paying someone to keep them locked in a planet. Since a working inmate is more profitable than a non-working one...

• Where is that comic from? :) – SK19 May 8 '18 at 22:02
• This is slightly off the mark. I love the comic, but the idea is for that paragraph you quoted to be real, rather than just doomsaying. Some of those businesses mentioned in the comic did go under. Good riddance. Others popped up in their stead. So if the planet can't survive, it goes under. But yes, it will go under without slaves. Still, good food for thought, here. +1 – João Mendes May 8 '18 at 23:03
• Well, at least the last panel shows progress of a woman business owner. :-) – SRM May 9 '18 at 0:56
• – The Square-Cube Law May 9 '18 at 2:20
• "You are describing nowadays China [...] Alternatively, the population is made of the most dangerous criminals of the universe." So your answer is basically to call the planet either China II or Australia II. Interesting... – walen May 9 '18 at 13:58

This planet has variable magnetic field (or its star is prone to storms), which means using properly shielded electronics is prohibitively expensive in many areas.

The slaves would perform manual labor in open areas, like agriculture, mining and construction, because traditional electronics-based machinery can not operate there.

• This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post. - From Review – Bellerophon May 8 '18 at 19:47
• I suppose you're right. Bottom line, this is a simple concept that could be made to work well in a thousand variations. I'm sold. +1 and I'll be sleeping on it. – João Mendes May 8 '18 at 23:19
• @bellerophon I think it does answer just fine. It explains why the planet still needs slaves and what they do for the world to justify their existence. – SRM May 9 '18 at 0:58
• @Alexander Or, build simplified machines based on good old-fashioned vacuum tubes etc, which are immune to EMPs and other such disruption. Suddenly, instead of needing a whole slave class you just need slightly more Mechanics and many more Supervisors. – Chronocidal May 9 '18 at 10:14
• @Chronocidal which does sound more expensive than slaves – Pierre Arlaud May 9 '18 at 12:41

You appear to be asking two questions:

1. How can I justify slavery on this planet when it is illegal in the rest of the galaxy?

2. Can the slaves do anything about their condition?

Occam's Razor: All things being equal, it's impossible to maintain slavery

In the beginning was tyranny. It's relatively easy to maintain slavery under a tyranny. Those who dislike what the tyrant says are eliminated. Those who provide for the tyrant's needs (no matter how they do it) are supported.

As time goes on philosophers, statesmen, rebels, sympathizers, do-gooders, etc. come and go. A few wars are fought, and over time laws are passed that slowly begin to give The People greater political power. It gets harder to treat people "unfairly" (and that's in quotes because "unfair" is perhaps the most subjective word in the known universe, see the cartoon in Renan's answer for a good example).

Eventually you end up with a representative government where even an individual (with enough organization and effort) can be heard loud and clear. An no matter how valuable or necessary slavery may seem, that one person can start a wave of sympathy that, combined with a representative government, eventually leads to the eradication of slavery.

In other words, all things being equal, it's impossible for slavery to be sustained. In fact, as government becomes more representative, the shorter the period of sustainable slavery becomes.1

So, all things aren't equal. Something's upsetting the balance.

Frankly, a valuable or critical resource is not enough to justify slavery. During the U.S. civil war cotton was a valuable and critical resource. So much so that the South refused to ship whole docks full of it to pressure England and Europe to enter the fight on the side of the South. It almost worked.

However, it's difficult to imagine a resource so critical that it could work. To make things worse, the more critical the resource, the more it works in the slaves' favor. Go on strike, everybody dies, but the whole honking universe knows what happened because everyone was inconvenienced, enter the sympathizers, laws mandating change suddenly occur because, above all else, it can't happen again. We need something much more unequal (call it unfair) than this.

Worse, yours is a galactic empire with technology out the wazoo. You need a reason to justify no robots. You don't need full AI to dig minerals or cut down trees. In fact, a case could be made that half the jobs out there require no imagination at all. They're completely procedural and don't have automation today simply because the flexibility of legs, arms, and fingers have yet to be mastered by the tech. So we need something unfair and unautomatable.

Finally, slaves only make economic sense when it's cheaper to use people than anything else. Building pyramids with slaves today would never be economical because one very well paid crane operator is worth thousands of untrained people and the cost to maintain them (costs to maintain slaves can be mitigated by inexpensive replacement, but only to a degree). On the other hand, we still use low-pay workers to pick fruit, berries, and other food stuffs that machinery simply can't do yet. Long story short, we need something unfair, unautomatable, and economically viable.

1. Any unobtainium will do, but it needs to be unique to this planet. On a galactic empire scale, that would suggest a very large world so that a great deal of material can be collected at once. This makes it economically viable but hard on people (heavy gravity).

2. It can't be mining. Mines run out (it's difficult to imagine, but you can deplete a planet). That means a renewable something. A biological substance that is unique to the planet. The chemistry of the ground and atmosphere could be duplicated... so what would be hard to duplicate?

A nearby pulsar, with a whomping strong magnetic pulse that regularly sweeps the planet.

And that strong magnetic field in combination with the unusual chemistry of the planet produces... oh, say a tree sap that happens to be the only life-extending/fully-rejuvantive analgesic known to humanity.2 Better still:

• No automation. The rotational period of the pulsar is frequent enough and the magnetic pulse strong enough that you'd be constantly repairing or replacing anything that had electricity-bearing wires. The cost of automated operation would be enormous if it was possible at all. I'm assuming the average magnetic pulse from a pulsar would be impossible (if only economically) to shield.

• Difficult synthesis. Do-gooders can't simply say, "let's set up a factory that duplicates those conditions over on Tatooine!" because even if you could create the delicate combination of chemistry and magnetism that creates our biological unobtainium, the cost would be worse than just repairing and replacing the automation. Remember, pulsar, and little Johnny's "cosmic science kit" really can't duplicate that level of strength. So... no can do.

• That leaves people. And a lot of people, because you have an entire galaxy to supply and you're the one and only location that can do it. The environment may require environmental suits, but you can't have anything electrically driven on them or the magnetics will destroy them. You can't have a lot of metal at all or you'll kill the human via inductive coupling. That means an environment that needs no more than hazmat or scuba suits to harvest the unobtainium.

And since profitability is always an issue, you're either paying them next to nothing (keeping them in indentured servitude like the company towns of the U.S. early 1900s), or it's flat out slavery where pain avoidance is the primary motivator for work.

As I mentioned in the beginning, no society with any form of representative government will tolerate slavery for long because there will always be somebody who sympathizes with the plight of the enslaved.3

• Therefore, there will be a constant propaganda war going on to keep the galactic populace distracted about the real conditions on our slave planet. This will be a large, complicated, and sometimes illicit effort that will be a great sub-plot in the story.

• There will always be someone on the planet itself, one of the not-enslaved, who sympathizes with the slaves. These are dangerous people, because they will be planning (a) whistle blowing events, (b) armed rebellion, (c) aid societies and all kinds of solutions to try to help the enslaved. Don't underestimate these folks. Grassroots anti-slavery movements were a huge contributor to the U.S. civil war.

• Finally, there's the slaves. Slavery works because the enslaved are (a) emotionally drained (institutionalized), (b) physically drained (you only want them strong enough to work, not strong enough to fight, (c) disenfranchised (no one anywhere near them likes them, no "nearby" support), (d) unempowered (everything is provided for them, an entire welfare state, the threat of leaving that condition is frightening), (e) and controlled (regular oversight by armed and authorized agents).

Overcoming slavery in your condition would likely begin with an underground railroad that smuggled out both slaves and evidence of the slavery to encourage sympathy amongst the politically powerful outside the world. But whether or not they're successful will depend on whether or not your society is truly free — free to develop abolition societies or allowed to have religious beliefs that preach the equality of all souls before diety. It's a complex mix — but that's what makes a good story.

1So long as small groups of people can hide in the political shadows, and so long as there's an illicit desire that people are willing to pay bookoo bucks to fulfil, there will always be some slavery. Sex trafficing and the drug trade in our world today are a good examples. However, I'm assuming that organizations this small are outside the scope of your question.

2Nothing drives humans to spend money like the fear of death. With the possible exception of professional sports.

3You could always declare your galacitc empire to be a monarchy that doesn't tolerate free speech, but that's a very hard thing to do without a lot of sycophants. It took full engagement in a popular war-of-revenge for Hitler to convince the people to give him full power. After a while, that power could only be held by fear. And even that was beginning to erode by the end of the war. Generally speaking, people will always want a voice, and the cost of suppression probably goes up exponentially with the number of people you need to suppress.

• Brazil is a federative republic, and at least in paper everybody should have a voice and polictical representation. Slavery is outlawed. ... It pains me to say so, but we have a rampant slavery problem (it's what I talk about in my own answer). People are not openly sold markets, but in rural areas those the poorest are drawn into job offers that are traps and find themselves being tied by literal chains. – The Square-Cube Law May 8 '18 at 21:43
• @Renan, your point's not missed. The U.S. had been a democratic republic for almost 100 years by the time of our civil war. Regrettably, gaining a voice does not mean your voice is immediately or automatically heard - and corruption always gets in the way of the process. That's a level of complexity I left out of my already very long answer. My deepest condolences to you and your people. – JBH May 8 '18 at 21:49
• +1 for unfair, unautomatable and economically viable. The pulsar thing doesn't really work with there being free population on the planet as well as slaves, but the base concepts are good. One thing: I wasn't asking what the slaves do about their condition, I was asking what the slaves do in their normal day-to-day lives. – João Mendes May 8 '18 at 23:33
• This reminds me very much of Dune. Hanging around on worldbuilding is so great, because you see the other side of the coin. Helps me appreciate the books i read even more. – Hakaishin May 9 '18 at 10:08

Only the natives of this planet can do the work, and they will not do it willingly.

One narrative about why African slaves were brought over to work in the New World is that they made better slaves than the Amerinds, and so were worth the expense to obtain. There are holes in that story but it is a plausible one and you can adapt it to your scenario.

Your world is a hostile place, but the descendants of the original colonists have adaptions that make them able to survive the surface conditions. In a job which requires human labor, only these natives will be able to carry it out. Slavemasters and overseers must wear protective gear and cannot stay out for long.

These natives are disinclined to do much if left to their own devices. Or perhaps the masters are not interested in paying them what it would cost, which might be a lot. So they are compelled to work as slaves. This is justified by pointing out that their living conditions as slaves are better in many ways than what they were in the native state and so slavery is an improvement for them.

• Specifically with regard to the "hostile environment" concept -- I have heard that some slave owners in the Americas claimed plantations would not be possible without black-skinned slaves, because of their ability to withstand the heat and sunlight. (Your answer does not say why Africans were thought to be superior. This is one reason though I am sure there are others) – maharvey67 May 10 '18 at 21:02

3 Ideas that popped into my head

1. Manual labor, the planet has few natural resources and relies heavily on manual labor to accomplish construction and agriculture.

2. Genetic engineering, there's a market for figuring out how to manipulate the genome, and what better Guiana Pigs than actual people. This would explain the required breeding population mentioned earlier.

3. Resource gathering, in a dangerous area of the planet (that conveniently makes electronic communication difficult, if not outright impossible) there is a highly valuable resource let's call them X-Crystals (just as a placeholder). Theses X-Crystals are not only valuable on the planet, but also off world as well, due to some innate quality they have.

• 1+3 makes for a good combination. +1 – João Mendes May 8 '18 at 23:21

The industry will have to be agriculture, some very basic mining or harvesting operation.

Slavery makes sense only for extremely basic and unskilled jobs. Examples of slavery in reasonably modern times are cotton picking in the US, or canals and road building in Stalin's Soviet Union (using hand tools).

If job requires skill, slaves will pretend to be too dumb to do it. If job requires any kind of machines or tools, slaves will break them, or rather make it look like they broke on their own.

More over, job should have very simple and obvious measure of productivity: amount of stuff harvested, the length of a ditch dug in the ground. Any kind of ambiguity about results (like quality of stuff picked) will let slaves produce lowest quality.

So your basic industry will be picking stuff, and maybe digging it out.

Either picking fruit of spice plants (with paid workers doing the planting).

Or picking nuggets of unobtanium out of raw material mined out with pickaxes, or loosened by machine (driven by paid workers).

Picking up and sorting objects is a task that is notoriously difficult for machines: objects have different shapes and sizes, so they require very dextrous fingers, and farm produce requires gentle touch too. Sorting unobtanium from similarly-looking but useless minerals requires keen eyesight, and attention to detail.

Machines that can do that exist even today, but they are expensive, they break down easily, and as others suggested, you can have radiation environment shutting down with electronics, or abrasive dust getting into moving parts.

As for political/social reasons for continued slavery.

Planetside, both rulers and free citizens are OK with it, b/c that's how they have always done it, and b/c slaves are "unevolved savages", and will starve to death without "civilized supervision", or might even resort to robbing and killing "cultured citizens".

Galactic superpowers do not interfere b/c they do not care enough (just like we do not care about Chinese assembly workers, or Latin American farmers). And because the slave planet is the only source of spice/unobtanium, any action of any major power to "free the slaves" will be interpreted by other powers as an attempt to grab the resource for themselves.

If you read history of US Civil War, "free the slaves" movement has been going on for like 50 years before it. But it did not receive much support in Congress until it became the only way to avoid a defeat in the Civil War.

• I suggest you watch The Boy in Stripped Pajamas. Sometimes the slavers know the slaves are smart. They will be enslaved anyway. – The Square-Cube Law May 8 '18 at 18:19

The planet is rich of some kind of very rare resource, like oil... no, I mean unobtanium, and bases its entire economy on it.

Mining is an expensive business. Raw unobtanium geodes are brittle, and must be dug up with the utmost care, or they'll break into a low-quality dust.

Of course, the five interstellar nations of your galaxy have developed high-tech machines able to automatize extraction, but they are expensive... your planet doesn't have the means to produce the same technology on its own, or maybe just doesn't care.

When the mines were first discovered, whoever was in charge at the time just started shoving convicts in, and it became a local custom until "convicts" became an equivalent of "lesser caste", "untouchable" and "slave".

Thanks to those unnamed sacrifices, your planet can now trade and bribe its way in diplomatic relationships with the galaxy at large: the other nations are always in need of some extra unobtanium, after all, and they are much more happy to buy it for some third-grade neutral planet rather than from their interstellar rivals.

Of course, it doesn't have to be unobtanium and it doesn't have to be mining, but something that produces value and, for a reason or another, it benefits from free mass labor.

If the whole mining-operation thing seems too much cliché, I think you could justify slavery as some form of cultural - religious heritage; you would have an harder time explaining how it started and how it became so prevalent in your two centuries limit, but that's nowhere near impossible. The roman empire, as many others, was built on the back of slaves after all.

• Raw unobtanium geodes are brittle, and must be dug up with the utmost care, or they'll break into a low-quality dust. +1 for this bit. Yes, slave miners is a cliché, but that doesn't mean it's immediately a bad idea. :) – João Mendes May 8 '18 at 23:13

A totalitarian religion should do the trick. The 'dirty' jobs can only be done by the 'unclean'. The 'unclean' cannot be part of the religion, leaving the religion is punishable by slavery or death. Does not take much for people to go along with this plan. Plenty of examples of countries that treated different sub-populations as less well than their animals. You don't need to work hard to find a religion that can be extended for use in this scenario.

For more inspiration look no further than the Gulag Archipelago.

Slavery doesn't have to be in your face it can be much more subtle like not providing adequate funding for education and making prisons, policing, healthcare private businesses.

Or that there be an external threat (real or conjoured) so that people are less likely to challenge authority.

• This sounds a like a certain country that I live in. – Tyler S. Loeper May 10 '18 at 14:52
• Oh I'm sure it's just co-incidence :D – Pinback May 10 '18 at 14:56

In the described scenario the reason(s) almost have to be cultural or the practice would be more widespread; slavery tends to be economically expensive to societies that use high levels of slave labour when compared to the same society using a willing workforce. In the past purely cultural reasons for slavery have included their role as a status symbol for the owner and the role of slavery as a penance with the goal of the enslaved paying off a social dept of some kind to regain their lost honour. As to the role of slaves within a culture that uses them, this tends to be work that no-one else wants to do, either because it's dangerous or its excessively hard or considered "unclean". Possibly you could make mass slavery pay but the goods or services that the slaves were producing would have to unobtanium level expensive.

The solar system in which this planet exists carries out an annual lottery, in which 99.9% of the entrants are winners of life-long wealth, but the losing .1% are assigned to the slave planet (to mine the resources that fund the lottery). Thus they are slaves by "choice" (obviously not having read the fine print about the beatings) on a planet whose rare resources (think Spice) can only be obtained by manual labor, due to the double ferromagnetic moons.

• Welcome to Worldbuilding.SE. When you have a moment, please visit our tour and our help center to learn more about us. The OP states that slavery is illegal in the rest of the empire. Your answer would be improved if you explained how this lottery is getting under the legal system. Thanks! – JBH May 10 '18 at 0:18

A Deal With the Devil

This question sounds a lot like a utilitarian thought experiment. Perhaps there isn't anything really special about the planet itself, it is just that the entire civilization is built around a few suffering to benefit the many. There are various reasons it could arise.

Just sign here... Perhaps a literal deal with the devil. Perhaps a pact with some pandimensional entity with Orange and Blue morality allows the remainder of the galactic civilization to be a utopia, all for the low price of letting one tiny blue planet be the hell on Earth.

Bread and Circuses Humans really like reality TV. The entire galaxy enjoys the real life drama shows. Without them the great democratic civilization would collapse. RealTV Limited only needs one planet. Everyone agrees that it is worth a few criminals and wannabe stars suffering. Well everyone except people on one particular planet. Technically they can still vote, but one planet isn't enough to get even on seat of the senate.

Unobtiani-sufferanium. Perhaps the civilization is powered by emotion. Perhaps the suffering is packaged up and shipped out. Perhaps a single planet suffering punches a whole in the warp and creates an objective anchor that can be used to break the law of relativity allowing telekinetic psions to push ships faster than light. In any case the suffering itself is the resource that allows the rest of the civilization to be the utopia it is.

The planet's a giant sexual fetish resort, and everyone there, master or slave, is there willingly. The slaves come because they find the idea of being chained up and dressed in scanty leather-and-metal outfits arousing, and the masters are there because they find the sight of half-naked slave men toiling away in the sun while similarly half-naked slavegirls lounge at their feet and hand-feed them grapes enjoyable as well.