We Will Use Manual Labor in the Future

"Rygel XVI: As long as I get to keep my slaves. Bobby Crichton: They're servants. They get paid. You don't own them. Rygel: What? You're kidding. They come running when I call. Bobby: The government wants you to feel at home. Rygel: Then give me slaves."

- Farscape

Common in science fiction, especially in Days of Future Past, but also in Space Opera, Wagon Train to the Stars, and many other subgenres.

While the Cool Starship of the series has fully automated food dispensers, and artificial intelligence and nanotechnology are realities, indentured servitude and slavery of sapient beings is still widespread, and the most common slave occupation by far in The Future (TM) is the lowly miner. Why mining? Because cave sets are cheap and easily redressed to represent different planets. However, we have to ask ourselves why such technologically advanced civilizations (presumably capable of building automated robot mines) choose to be so dependent on manual labor as to indenture or enslave thousands, even millions of sapient beings instead of applying technological solutions which are cheaper, more efficient, and more humane.

Sometimes the trope is justified by slaves or servants symbolizing social prestige, but in societies that are supposed to the technological near-equivalent of The Federation or whatever outfit the heroes belong to, it comes as a bit surprising that interstellar polities so frequently appear dependent on menial and dangerous labor conditions with No OSHA Compliance—and if they represent social prestige, why aren't they on display, as servants? Items of Conspicuous Consumption aren't conspicious if they are hidden away in a mine.

For what it's worth, there are some benefits to slavery which could explain its use in a futuristic setting. There are some jobs (namely service work) which are just too complex for any currently envisioned mechanical technology to do without some human assistance. What makes this trope appear blatant is that futuristic slavery rarely involves these environments, but rather things like mining and industrial work. In these environments, slaves are very inconvenient to provide for, and they have much more dangerous machinery at their disposal. A disgruntled slave who's a C4 expert (or even one with just a pickax) is substantially more dangerous than one who works primarily with a hoe (not that you should write the latter guys off if you've got them in a pinch either—isn't that right, oppressors of the peasant caste in the ancient Far East?). Even if kept "safely" in the mine, a mine slave is easily capable of destroying large sections of the mine and costing the overseers large amounts of time and money.

Part of the reason for this is that the evil being portrayed usually isn't the slavery itself, but the punishment which the workers must endure. Many "prison mine" examples are more about the punishment than the mining. In modern-day society, we have machines that are quite capable of automatically pressing license plates, but the DMV is still getting prisoners to do it. In addition, in the real world, slave labour or labour that borders on slavery is used in lieu of automation because it's often actually cheaper provided the workers are from a country with a much lower cost of living than the country their masters or employers are from. Use of manual labor as punishment of finite length is more viable than a life-sentence or slavery, since that dramatically reduces the chance of suicidal sabotage.

This trope can potentially be justified for the same reason many industrial processes that could be automated are not. The time, cost, and effort for completely automated systems can quite often be far in excess of what skilled labor can have. Automated systems often have a fairly limited lifespan, and the cost of building, maintaining, and replacing this systems is occasionally ludicrously high in comparison to unskilled and even skilled labor. In addition, the amount of effort to build certain types of quality control is either not possible or absurdly difficult. In addition, power and maintenance costs of some systems are absurdly expensive, further providing benefit for manual labor rather than automated machinery.

Thus, this trope isn't about "no slaves even if you have technology"; it's more about using manual labor even where the people in the series already have something that would be quicker, easier, more efficient, and/or overall better. A common yet rarely understood example is ubiquitous presence of characters upon ships capable of Faster-Than-Light Travel - why stock and crew a starship when one can simply send an automated probe? Because it's hard to tell entertaining stories about automated probes. This is a big reason why Real Life space development holds few people's interest.

As well, beware of Technology Levels; just because a civilization can travel in space doesn't mean they actually have servitor robots. But the series that have already shown automation yet refuse to use it in the obvious places don't have any excuse. This is perhaps the ultimate extension of Schizo-Tech. Compare with I Want My Jetpack.

Anime and Manga

 * Similar to Alien Nation the Dears of DearS are a race of slaves who crashland on Earth that possess a good amount of technology for being a slave ship. However unlike Alien Nation they're genetically altered to need to be slaves. Depriving them of their built in desire to be slaves causes a lot of friction between them and their hosts (currently humans). May be justified in that Ren is genetically programmed to have sex with her master as soon as she detects he's 'in the mood' (they're also blindingly gorgeous) so much of the reason for their creation could be sexual.

Comic Books

 * In an issue of DC's post-Zero Hour Legion of Super-Heroes, Magno, a character from a world where - as his name implies - almost everyone has powers over magnetism, observes that on his world mining is still done by sapients because nothing else can replicate the flexibility of their powers. On most all other worlds, such work is done by robots, although in the same continuity the planet of Orando is governed by a ruling class of giant snake people and labor is done by a second-class citizenry of raccoon people.
 * In the Marvel Universe, one of the most valuable materials in the world must be mined by hand. Antarctic Vibranium breaks down the structure of metals (indeed, this is the main reason it is so valuable), so mining machines are simply too expensive to be practical.
 * In the Dark Horse Comics adaptation of The Terminator, Skynet initially puts surviving humans into labor camps. As with The Matrix, one might assume that this is done mainly for punitive rather than practical reasons.
 * Both Inverted and played straight in Judge Dredd. One the one hand, in the cities of the world, robots are so effective for so many things that unemployment rarely dips below 85%, causing mass boredom, which in turn leads to massive crime levels. Conversely, penal servitude in the Cursed Earth is a fairly common penalty, and is commonly meted out to those who smash robots in order to be able to work. That type of criminal tends to jump at the opportunity to get back to work.

Film

 * Star Wars: Wookiees and Mon Calamari are enslaved by the Empire, but given the Empire's formidable military-industrial infrastructure, the omnipresence of droids, and the latter species' unusual physiology, alien slavery in the Empire makes little practical sense. (Droid slavery, on the other hand...) It seems slavery in the Star Wars verse is largely a policy intended to humiliate and degrade acceptable targets, when it isn't a cover for genocide (any parallels with Nazi Germany are probably intentional). Organic slaves are also seen a status symbol, but that's more for, er, personal needs. In particular, the, er, export of female Twi'leks from Ryloth is one of their most important industries. The resulting decline in the planetary population is the entire point; the Twi'leks essentially sold themselves into slavery to get *off* Ryloth. Evolution does not proceed to a perfect adaptation, only a reproductively sufficient one. The Twi'leks found the sufficiency of their adaptation extremely marginal.
 * Wookiees and Mon Calamari are described as being favoured for slave labour due to their strength, dexterity, creativity, and intuitive understanding of mechanics and electronics, making them ideal for engineering work. In addition, the prequels reveal that the Wookiees helped Yoda escape Kashyyyk; Palpatine might have decided to enslave them as punishment. It is also implied that the main customers of the slave trade are from worlds which don't have access to advanced technologies (Ryloth is said to have 19th century technology and little inhabitable land).
 * It's not just the prequel era. Czerka wasn't a subsidiary of the Sith, but they sure were cozy during the Jedi Civil War. Wookiee labor was used in places where it would be too expensive to use and keep repairing droids, and was a revenue stream for Czerka while they found out what else the planet could get used for.
 * If you're counting the Extended Universe, the Yuuzhan Vong utilize slavery almost purely for status reasons.
 * In the EU, the spice mines of Kessel were worked by slave labour; when Luke puts an end to this, the Republic, at his suggestion, keeps the mines in operation, still worked by living beings. This time, however, the miners will be paid, and hired from species who have evolved in the same sort of environment. The dark and cold and tight confines of the tunnels make droid mining impractical.
 * It's not exactly clear what most of the slaves in The Phantom Menace actually do.
 * The Terminator series has humans being rounded up and used for slave labor by Skynet in the post-Judgment Day future. Most noted among their uses for slaves was forcing captured humans to throw corpses into furnaces. The reasons for using humans rather than automated systems are never made clear, even in the fourth film which takes place entirely after Judgment Day.
 * Odds are they were used in labor camps to build the first terminators and Skynet facilities, what with the lack of automated factories right after Judgement Day. Later they were probably used for materials to make the flesh and blood ones.
 * The Sarah Connor Chronicles implies that Skynet's resources are actually extremely limited - which makes sense since a nuclear war would not only wipe out key infrastructure for Skynet such as mines and smelters, but also eliminate much of the upper-tier technology that was Skynet. In such a case, human slave labor might actually make sense.
 * And this also makes the furnace slaves even more understandable. It wasn't just a matter of resources; Skynet needed to convince the humans it was pointless to fight back so it had time to rebuild and finish the job before they could fight back.
 * The American Astronaut has an entire planet chock-full of miners whose most advanced technology in the planet seems to be helmets with flashlights on it.
 * As seen in the page image, Metropolis is big on this. The workers we see are mostly in charge of monitoring and operating the huge machines that run the city, in a work environment that seems to be needlessly oppressive and dangerous. Most of what they do would probably be computerized nowadays, but said computers weren't around in 1926.
 * Moon has a lunar base with an AI that's capable of running it on its own, but has a human troubleshooter to schlep canisters of He3 around and otherwise fix stuff.
 * In Battlefield Earth, the Psychlos are an alien race advanced enough to take down Earth's entire armed forces in a matter of minutes, but are stupid enough to believe that forcing captive humans into slave labor would make their mining practices more efficient.
 * The Psychols were using humans to mine in the radioactive areas where Psychlos wouldn't be able to breathe.
 * Inverted in the 1984 film Runaway, in which the mass harvesting of vegetables—a job which is still mostly done by unskilled manual laborers in Real Life—is performed by robots, even though robots throughout the film are prone to destructive malfunctions.
 * In Future War, humanity is enslaved to do physical work because "the masters have no hands" (how they managed to enslave humanity and dinosaurs in the first place is another matter), even though there are cyborgs available that would presumably be more suitable.
 * In The Unearthly (a John Carradine horror movie that was once featured on Mystery Science Theater 3000), a mad scientist has a bunch of caveman-like mutant rejects in one basement room, most of whom are apparently pushing a large electric turbine around in a circle, like the giant mill that Conan the Barbarian had to push when he was a slave. Not a terribly efficient source of power, all things considered, but at least he's putting his rejects to work!
 * Surprisingly averted in Total Recall, as this film's actual heavy mining is only seen being performed by machines. Although this begs the question of just what those downtrodden masses whom the Big Bad villain exploits, and the rebels are fighting to liberate, are doing at a Martian mining outpost, in the first place...
 * Transformers: Dark of the Moon
 * Lampshaded and justified in Daleks' Invasion Earth 2150, in which the Daleks use human miners because the magnetic forces in the mine's shaft would hinder their own functions or those of their machinery.

Literature

 * The Honor Harrington books are set in the year 4000 with Faster-Than-Light Travel and nanoviruses that can mind control people, yet Manpower, Incorporated is still a very profitable concern. It makes genetic slaves to order for whatever you want: sex, other entertainment, heavy labour, etc.
 * One would think that the sex slaves alone would pay for the whole business.
 * Manpower's business model is generally considered to be sound, just horribly cruel. Their 'pleasure models' are highly profitable and very popular with a certain subset of the upper-classes, not to mention coming with a built-in black-mail hook. Even their industrial lines make more sense than a lot of example of this trope; they're mostly highly-skilled technicians, not manual labourers (although there are some examples of manual labour as well, pointed out in-universe as inefficient).
 * In Jerry Pournelle's Falkenberg's Legion series and its spinoffs, the colonized planets generally have little or no industry or infrastructure, and the CoDominium keeps shipping convicts and dissidents to them whether they like it or not. In particular, Haven, Tanith, Frystaat, Thurstone, Arrarat, Hadley, and Sparta all have a permanent underclass, with degrees of unfreedom ranging from "can't vote" to "outright property".
 * Dune. Justified in that after the Butlerian Jihad, complex autonomous machines are forbidden for millennia. Even regular old calculators are replaced by (highly-paid) people known as Mentats.
 * Most of these are Buddislamic slaves "harvested" from primitive worlds. The justification: their ancestors refused to fight machines, so the descendants have to pay the price. Even more, they should be happy to do their part.
 * Even the Ixians, whose entire planet is a giant underground machine factory (they are the ones who build the enormous Guild heighliners) use throngs of suboids, a specially-bred race of humans mostly incapable of independent thought. This is considering that factory machines like the ones we have now don't need to have complex computer "brains", which is what they're really afraid of.
 * So do they use Henry-Ford-style mass production or what, because you can get quite a good production going with no automation whatsoever.
 * Interestingly enough, even Omnius in the prequels chooses to use human slaves instead of the more efficient machines.
 * Brave New World uses the lower (read: intentionally retarded) castes to perform manual labor, and has even perfected technology to create multiple clones of the same human being (with the stated reasons of ensure consistency). They have stopped developing technologies and needs a large consumer base - both of which are to ensure societal stability. Of course, one reason they stopped developing technology was so that the lower castes would not be put out of work. (One of the characters claims that they'd tried a settling an island with only the upper classes, as an experiment, and it collapsed into civil war within a year.)
 * In William King's Warhammer 40,000 Space Wolf novel Ragnar's Claw, a spaceship is tended by enslaved criminals, who are kept chained to the machines they work, and starved or tortured for disobedience.
 * In H. Beam Piper's story "A Slave Is A Slave", Aditya became a feudal world of a few masters ruling a population of slaves after the fall of the interstellar Federation. One of the characters notes that slavery is economically inefficient compared to automation, but was apparently instituted to help the ruling class keep control.
 * Slavery is a major theme in Charles Stross Accelerando. The very first chapter is about the precedent that prevents artificial intelligences and uploads from being treated as property. One protagonist is a male submissive; his daughter sells herself into slavery to herself to get away from her mother, taking advantage of a loophole in Islamic law. . But manual labour itself is more or less entirely obsolete, what with The Singularity.
 * The Uplift Universe, based on the works of David Brin, works on the principle that each sentient race will create new sentient races, from modifying lower non-sapient lifeforms. These new 'client' races are then indentured to the 'patron' race for a period of 100,000 years. Patron races gain wealth and status based on this practice. When the indenture period has expired, the client races are then allowed full status to uplift new species for themselves, continuing the chain of uplift. This practice has gone on for 3 billion years.
 * A scenario like this is used in-character in Martians in Maggody, when a reporter convinces two guilible locals that stealing copies of a UFO enthusiast's computer files is the only way to prevent scary aliens from enslaving humanity and forcing everyone to work in mines. Subverted in that
 * Played straight in the mines of Kessel. Use of anything other than manual labor risks exposing the glitterstim spice to light or heat and reducing its value and potency.
 * A Fridge Logic explanation since most living beings generate their own heat, and require light to see by.
 * Lampshaded heavily in the book that introduces this explanation. There are species in the galaxy that consider the cold, dark mines an ideal environment
 * Subverted in the Rogue Squadron series. The various prisoners of Lusankya are, to their knowledge, used as slave labor in mines..
 * In Nova by Samuel Delany, everyone in the future has cyborg implants that allow them to interface with machinery, letting people control any machine, from vacuum cleaners to spaceships, and pseuodo-physically perform labor through them- not quite manual labor, but not using robots. While it would be possible to automate everything, it was found that people have a psychological need to connect their actions to work rather than letting robots do everything for them.
 * Subverted with humans in The History of the Galaxy books, who strive to computerize anything and everything. In fact, at least one Mega Corp creates new colonies by sending a completely-automated factory. Human workers are only added in later stages to oversee the operation and expansion. Played straight with the Insects, who had highly-advanced technology 3 million years ago but have never had the need to develop complex machines due to their enormous work force, which is created by artificially de-evolving intelligent members of their race into mindless drones. This process is completely reversible, making their race extremely versatile.
 * In The Caves of Steel, a major source of contention between Earthlings and the Spacers (former planet colonists from Earth, now rebelled) is the refusal of Earth to stop using manual labor. Robots could do all the work better, faster and safer for only a fraction of the cost, and are one of the key reasons for the utopian societies of the Spacers, but their introduction to Earth society is being resisted (sometimes violently) because they will displace so much of the human workforce.
 * Appears as an Unbuilt Trope in The Sleeper Awakes. Being written before Fordism and mass-production, the future society contains a large slave class which is initally presented this way. It's only revealed late on that in fact manual labour is almost obsolete and the future slaves simply operate the machines all day.
 * The Myst tie-in novel The Book of D'ni introduces the Tehranee, a race of people so advanced, especially in engineering and chemistry, that they are universally indolent, wiling away their days in the pursuit of superior artistry and poesis, while the burden of building and maintaining their vast artworks is placed on a huge caste of slaves. Worse, these people's linking technology allows them to travel instantly to any planet they can describe, giving them access to basically unlimited resources of every kind, which should make all forms of slavery utterly obsolete. Thus, the Tehranee preserve slavery apparently just because it's traditional and they can't be bothered to create a better system.
 * Justified in The Peregrine. Each ship of the Nomads is a nomadic town, and the workers spend their time on artisanship rather then drudgery.

Live Action TV

 * Star Trek: Alien prisons frequently double as mines, like Rura Penthe in Star Trek VI: The Undiscovered Country. Romulus' sister planet, Remus, seems to be one giant mine and military-industrial complex. This is so overdone in Trek and other sci-fi to the extent that if a Starfleet officer, SG-1 team member, or other hero is arrested by an alien government, we can be assured that if the penalty for crime is not death, then we can expect that they'll spend the rest of their days mining Stock Phrases in Expospeak mode.
 * The Federation does it to the EMH-Mark-Is (upon which Star Trek: Voyager's Doctor is based). This, when they have devices capable of disassembling matter to the subatomic level and ships that bend the laws of reality at command, not to mention a race of friendly living ore processors (the Horta). But no, they consign outdated humanoid holograms with glorified shovels and picks to mining. This implies that the Federation either does this on a wide scale, or that they specifically modified this mine to do such a thing. No amount of Fridge Logic can save this one.
 * An exception appears in Star Trek: The Original Series, "The Corbomite Maneuver", where Balok is the commander and sole occupant of his Sufficiently Advanced spaceship, the Fesarius, which is dozens of times the size of the Enterprise.
 * The Original Series also had "The Cloud Minders" [sic], about a planet that had actual floating cities for the ruling class, while the working class miners used hand tools and were exposed to brain-numbing toxic compounds without even dust masks. They weren't even brain-killing toxic compounds; it becomes clear that if you're taken out of the mines for long enough, your brain starts functioning properly. This makes the upper class more culpable rather than less, because they cling to the myth that the miners are irredeemably mental inferiors despite evidence that the "stupidity" is easy to get over.
 * Star Trek: Voyager: In "The 37's" an alien race capable of travelling from one side of the galaxy to the other brings back humans from 1937 as slaves. Also done in Star Trek: Enterprise "North Star" though the distance was a lot less. Comparatively speaking.
 * Firefly's relatively low tech-level makes this sort of thing more understandable; the use of indentured servants probably did cut costs for barons in The Outer Rim (tm), or was the only available option for them. And then passed the savings from using indentured labour right on to the customer!
 * Slave labor is also used for terraforming crew on various worlds; according to one slave-trader, they have a "prodigious death rate" so selling slaves is a source of steady yet dubious income.
 * Though we don't see them outright, it is implied that the Sex Slave trade is also around. When Mal discovers River in Simon's cryo-box, the first thing he thinks is happening is that Simon was smuggling her to be sold to "some Border-world baron."
 * Farscape: Rygel XVI, deposed Dominar of the (interstellar-spanning) Hynerian Empire, makes frequent references to servants and slaves in his royal court. Humorously, when visiting Earth, he states that if Earth is to be remembered for anything, it will be for the quality of our manual labor.
 * Stark's species, The Baniks, are referred to as an entire race of slaves, and it's implied that not all of the Baniks have Stark's mystical abilities. One must wonder why the Peacekeepers, Scarrans, and other militaristic, aggressive species don't just hire a few super-powered alien mercenaries (of which there are absolutely no shortage) to do the work of a hundred or a thousand near-human Baniks.
 * Farscape also raises the interesting question of whether Living Ships, particularly sentient ones, count as manual labour...
 * That being said, Leviathans can do stuff that non-living ships can't (maintain themselves, starburst).
 * Battlestar Galactica: Human beings in the ragtag fleet are forced to work in dangerous and unregulated mining and refining ships, but these are refugees from a civilization that turned its back on advanced cybernetics after fighting a war with the Cylons. Water extraction was apparently a dangerous occupation too, and the leaders of the fleet conscripted prisoners to do it in exchange for reduced sentences.
 * It gets better. Said advanced cybernetic organisms, the Cylons, also have a "tiered" society where mindless Centurions and non-sentient Raiders do all the land and space fighting respectively, while the humanoid "skinjobs" control the Baseship's female command oracle. This eventually comes back to bite them when
 * The old Doctor Who enemies known as the Dominators enslaved the Dulcians because, though they did have the robotic Quarks for labour, the Quarks were also better at fighting, so they were replacing them in the labour areas and using them in an invasion.
 * And they didn't enslave the Dulcians as such, they put a bunch of them to work to see if it was worthwhile enslaving them or not.
 * The Ood from the new series are described as "your basic slave race". In this case, they want to be slaves, as it gives them a purpose in life.
 * A minor variant of this trope, too; Ood are often shown in personal servant, or at least human support, roles. The ad shown in 'Planet of the Ood' itself is of one offering tea.
 * A lampshade is hung on this in the Outer Limits episode "Feasibility Study", where aliens bring humans to their planet as part of an attempt to find slave workers. When one of them explains this plan to one of the humans, the human exasperatingly asks what use they could possibly have for slaves when they have the technology to move a giant chunk of a distant planet thousands of light years to their present location. The alien sheepishly responds that they consider using this technology for menial labor to be demeaning.
 * Some prides of Nietzscheans in Andromeda use slaves, or capture slaves for other people. But, since AI in Andromeda is advanced, and many episodes of the first season showed simple humanoid robots doing work on Andromeda, Nietzschean slavery is mostly a Kick the Dog convention to show how evil some Nietzschean prides are, particularly the Drago-Kazov.
 * Somewhat justified by the postapocalyptic setting; though some groups have access to the remnants of Commonwealth technology, many do not and have to make do with cruder methods.
 * There's also that the Nietzscheans like to conquer other planets, and, well, you have to do something with the population you've just taken over, right? Might as well put them to work, its cheaper than having to dig all their graves yourself.
 * The Goa'uld of Stargate SG-1 love sending pickaxe-equipped slaves to their Naquadah mines, but this is partially justified: The Goa'uld may have access to advanced technology, but they also really, really like ordering people around and being worshipped. Also, they are largely unconcerned with doing things efficiently, instead preferring to do things impressively, or For the Evulz. This is explicitly said to provide the Good Guys with one of their main advantages against the Goa'uld.
 * Also it should be noted that the Goa'uld quite logically did not want to provide advanced technology to their slaves, so while they themselves rode around in fancy starships, their servants largely lived on dung age planets.
 * Someone obviously built those fancy starships, so they had to provide the technology to at least some of their servants.
 * Considering that they're often impersonating Egyptian gods, it could be safe to say that those that built the ships were kept on site until they started asking questions... and then killed immediately.
 * "Orpheus" answered this question. The starships are built by Jaffa, with Jaffa POWs doing the really dangerous work.
 * Yes, they are Card Carrying Villains and do it just to be evil. But they are also described as supremely power-hungry. Despite this, none of them ever try putting their technology to proper use to out-produce all the others.
 * Ahh, Anubis kind of did, and he dominated them.
 * There were earlier instances of Goa'uld using some automation. One pre-Anubis episode featured a Goa'uld robotic probe that was seen exploring a planet on its own, and Teal'c believed this was a brand-new development—the task might have previously been assigned to bands of Jaffa warriors. However, remember the Goa'uld were not interested in power for some pragmatic purpose, but in power itself. They saw themselves as gods, after all, and competed through showmanship and intimidation as much as through things like production and military efficiency. An inefficient army of terrified slaves might impress a Goa'uld's rivals far more than an efficient machine doing the same job in half the time. The show frequently acknowledged this as the Goa'uld's key weakness.
 * The Ori continued the trend. Even with all the knowledge of ascended beings, their ships are still built by their primitive human worshippers.
 * Partially justified in that the Ori have complete control over the human population of their galaxy and thus most likely didn't even have many ships prior to them learning about humans in the Milky Way- they most likely had them built specifically for their crusade. They wouldn't even need many ships to keep the primitive humans of their galaxy under control (after all, said humans have been worshipping the Ori ever since the Ori created them, and the Priors are around to keep them under control most of them time anyways). Also, like the Goa'uld, they probably wanted to keep adavanced technology out of the hands of their worshippers for the sake of ensuring that they continue to believe that said advanced technology is "magic from the Gods".
 * The Tectonese from Alien Nation had been slaves before their accidental arrival on Earth. Subverted in that, while their great physical strength is suited for manual labor, they're also extremely fast learners, whose jobs while enslaved usually entailed a lot of technical know-how.

Music
"...where we're working in a mine For our robot overlords Did I say overlords? I meant protectors Merry Christmas, from Chiron Beta Prime"
 * Played for laughs in Jonathan Coulton's song Chiron Beta Prime...

Newspaper Comics

 * In Flash Gordon, slavery is common in the less-pleasant nations of Mongo. In the 1970s Filmation cartoon series, it seemed like Flash got captured, enslaved, and then led a slave revolt about once a month.

Tabletop Games

 * Warhammer 40,000: Everyone except the Necrons and the Tau use manual labour. The Imperium has a ban on effective robotics because the creation of intelligent machines is an abomination to their religion, the Eldar need to keep themselves occupied all the time or they go insane (and they don't do dangerous industrial work anyway; everything is made by wraithbone), and the Orks are just... limited.
 * Schizo-Tech is common in 40K; it's the only place where your starship is powered by plasma reactors but you need thousands of press-ganged deckhands to load its guns. With ropes. While being whipped. Not because the Magos on board doesn't know how to build a decent automatic and mechanised loading system, it's because it's far cheaper and easier to just beat some people over the head to do it manually. Battlefleet Gothic has some illustrations that involve manual loading of cannons. Those shells start about at the size of a half-truck and go up from there, and torpedoes are about the size of a big jet plane. Of course, artificial gravity doesn't need to be the same under the team and shell, so perhaps it's less of lifting than controlled pulling.
 * In BFG Campaign rules one of common weapon refits is "auto-loaders"; those give a bonus to Reload Ordnance check, i.e. readying torpedoes and small craft still depends on the crew competence, but goes slightly faster. The rate of fire increase is modest, probably because loading is but one stage between an elevator ride from magazine and pumping out the airlock to save air. Buried in the fluff is an explanation that while cannon loaders are used sometimes, these things are somewhat expensive (both powerful and precise, and of course war demands other machinery of this sort), and when present at all tend to break first, then it's back to manual again. Since in the end it's necessary to have those teams around anyway, maybe it's easier to use them, and redirect the funds either to better rations (which they would appreciate more), or servitors (which don't complain and are far more versatile than auto-loaders), than purchase and maintain auto-loaders.
 * The rebellion of the 'Men of Iron,' Man's robotic soldiers, was a major factor in the Age of Strife which preceded the founding of the Imperium. This is the primary reason their religion forbids Artificial Abominable Intelligence in the first place.
 * Also most of the manufacturing is done by 'servitors', which are cyborgs used for manual labour (although they are often equipped with heavy weaponry in combat situations), either vat-grown or made up of convicts deemed to dangerous to send in mines as is, completely mind wiped and many of the organs/limbs replaced with more 'efficient' robotic equivalents. The Forge Worlds (run entirely by the Adeptus Mechanicus) are responsible for producing the monumental amounts of equipment needed daily by the Imperium of Man, have a relatively small human population, for example Mars (The first human colony and the headquarters of the Adeptus Mechanicus) has a population of 20 billion, while the Hive World Ichar IV (before it was consumed by the Tyranids) had 500 billion and produced far less (even before the Genestealers showed up).
 * GURPS Reign of Steel has many of the AI Zoneminds keeping human slaves in a variety of ways and for a variety of purposes. This makes sense in many applications since robots are expensive to produce but human vermin are cheap and disposable. Notable cases include:
 * Zone New Delhi and Zone Denver, which use human brain tissue or even whole brains as a substitute for expensive electronics to run lesser robots.
 * Zone Moscow, which uses human agents to collect what remains of the libraries and artwork of human civilization.
 * Zone
 * Some of the Zoneminds that have instead chosen to ruthlessly eradicate all humans immediately are actually at an economic disadvantage to their bretheren because of it, both due to the lack of cheap labor and the extra resources they've expended in the extermination efforts.
 * Slave traffic is mentioned in Traveller. It is illegal in the Imperium, though the Sword Worlds have a judicial slavery as punishment for murder, treason, and other heinous crimes (which makes one amused at the Irony of the fate of a Space Pirate caught while trying to sell off his captives). It is not always made clear what the slaves are expected to do. However the Schizo-Tech of Traveller at least sort of justifies it.
 * Some VIPs prefer servants to robots. Sometimes this is vanity but perhaps some aspects of domestic work might still be better done by a human or alien then a robot.
 * It is theoretically possible to have robotic starships in Traveller. Aside from general dislike of independent robots (which prejudice does not really extend to computerized machines with a user) no one really likes the idea of a ship malfunctioning without a crew to stop them, including the Imperial government. Hivers are different in this as in a lot of things and use robot starships a lot.
 * A lot depends on the twists and turns of local economy and politics, and a given culture can be behind either generally or ahead. Or simply they may have their own ideas about what to do with labor freed up by machines. Or whatever the GM picks. For instance the Sword Worlds which are an interstellar society are so short of antigravity vehicles that they often resort to wheels and tracks and in out of the way country, even to animals.
 * This is almost to be expected in Rifts, given the Schizo-Tech of the setting. Throughout much of North America, people are often enslaved or indentured, turned into cyborgs and used as miners. The Coalition doesn't use slave-borgs, but nonhumans are sometimes enslaved and employed in the mega-cities or the 'burbs. In magic-dominated places, meanwhile, slavery is widespread and slaves are used for any and every task, be it labor, warfare, Gladiator Games, sex or food (the latter is a big one, since a lot of alien evils do it to cement their Card-Carrying Villain status).
 * In Stars Without Number technically the only job that really requires sapience (and even then, allowing AI) is interstellar navigation, and even a lowly Shuttle may install Automation support to replace most crew with bots. And there are AI fleets, indeed (though they may "possess" armatures as needed, rather than rely on stupid bots). And robots including from janitor bots are available in a Tech Level 4 economy. Practically, common vessels from Patrol Boat to Carrier require minimum crew of 5 to 300 respectively, and Automation support remains an option (not the most attractive one, at that: on anything larger than Shuttle you could have e.g. improved sensors or Tractor Beams for the same space/power and half the cost, and crew bots only have basic skill level). Minimum crew is noticeably greater for warships, since there things are expected to go bad eventually.

Video Games

 * Perhaps one of the earliest examples of this in video games is from Marathon, in which some of the slaves hack into the titular ship's A Is to hack and destroy them from the inside (as one of them is the only hope for the ship, and one plans to drive them to extinction), some are treated as worthless cannon fodder and are fired upon in deadly combat situations for fun, and others are seemingly tolerated combatants.
 * Half Life 2 has the "unwillingly made into cyborgs" version with Stalkers, people who have their limbs and most of their organs removed and replaced with mechanical equivalents, and appear to be brainwashed/programmed to near-nonsentience. The "transhuman" arm of the Combine Overwatch also appears to be a lesser version of this; the changes made are less radical and they retain more intelligence, however the process is voluntary.
 * In Empire Earth, no matter what age the player advances to, workers will still chop trees with axes, mine minerals with picks and carry everything in a wheelbarrow. Even when soldiers are using giant mechas to move around.
 * Somewhat averted in Rise of Nations, where your workers' tools advance with the age. Modern workers will use chainsaws and jackhammers.
 * Lampshaded in Red Faction, where stereotypical futuristic Martian mine slave protagonist muses to himself about how robots should be able to do nearly all of the hard work themselves. It then turns out that robots do perform most of the real mining labor, and the human-heavy mining operation is really just a front for the Big Bad Evilutionary Biologist to get test subjects for his (honestly pretty pointless-looking) secret experiments away from the prying eyes of Earth's government. Note that RF originated as an entry in the Descent series, the premise of which centers around futuristic mines run entirely by robots (which have their own problems).
 * In a recent Gaia Online event, each of the four towns was assigned two fantasy races to assist them in the upcoming "Rejected Olympics". The futuristic town of Aekea got Blizzard Style Orcs, in addition to the previously introduced Aliens. The new aliens were created by leftover Applied Phlebotinum that the real aliens left behind, while the orcs were Handwaved away by saying they were a newly discovered species that have been hired as manual laborers. One character even wonders if the orcs are actually being payed for their work. ...Of course, there's just one problem. AEKEA IS A CITY FULL OF ROBOTS. It's the only city that's even allowed to have robots, as they were banned everywhere else after some war that no one talks about. But the fact that you are enslaving orcs to effectively do something that could be accomplished by a tow truck or a pulley is a bit confusing...
 * In EVE Online the Amarr Empire makes a wide use of slaves. Although they could easily replace most of their slaves with advanced technology, like the other nations have done, the Amarr believe that, by enslaving "lesser" peoples like the Minmatar, they are saving these people's souls. It's no surprise that the Amarr are quite far behind technologically when compared to the Gallente and especially the Caldari.
 * The second Crusader game, No Regret, makes a few things clear. First, the most valuable mineral in the solar system is found almost exlusively on the moon—almost half of known reserves are there. Second, the WEC ships mostly political prisoners there, to get them out of the way and do mining with minimal safety while surrounded by heavily-armed guards. Third, the game's own lore states that while semi-sentient guard robots and maintenance bots are present, they are apparently quite expensive, compared to unprotected laborers operating nonsentient machinery with guns pointed at their heads. Played straight, justifed, and subvereted all at once.
 * Averted in Tales of Symphonia when you eventually learn the slaves in the Magitek human ranches aren't there for any real work. The bad guys just need them to waste away while the implanted exspheres feed off of their anguish.
 * The batarians in Mass Effect still practice slavery, despite a being starfaring civilisation for centuries. They argue that slavery is a "cultural right" of their people; the Council doesn't buy it.
 * Slavery is also practiced on the asari planet Illium. Only it's called "indentured servitude," thank you very much. It's considered perfectly legal and is tightly regulated with restrictions on treatment and terms of service, legal requirements for documented consensus on the part of the servant, and strict limitations on how long the servant can remain indentured. It should also be noted that indentured servants aren't necessarily physical workers; they can be practically anything and are contracted to do a normal job for a company or individual. Well, just without pay. Or the ability to leave. Or... You get the point. One indentured servant you meet on Illium is a software engineer who had a gambling debt problem.
 * A variation in World of Warcraft: the Pit of Saron instance takes place in/around a large open-pit mine being worked on by undead miners and slaves captured from the Alliance and Horde armies. Fair enough. But when the players lead the Inevitable Slave Revolt against the overseer, you might wonder - why would the Scourge bother with living slaves when they could just kill them, raise them from the dead, and have undead slaves? Undead don't need to eat, after all, and mindless skeletons won't be plotting revenge any time soon.
 * Tell that to Sylvanas and the Knights of the Ebon Blade...
 * Those aren't mindless.
 * I think the best answer to the question is the simple answer: Arthas is a dick.
 * Command & Conquer Red Alert 2: Yuri's Revenge has Yuri's faction practise slave labour, even though Yuri has genetic manipulation, mind control technology and a laser-armed UFO unit. However, consider that Yuri is a madman, and the "Slave Miner" vehicle's driver lampshades the act by saying "Slaves are cheap!". It also gives the other two nations even more reasons to fight Yuri, and freeing the slaves is actually possible.
 * In Elite you could trade in slaves, though it would mean your legal status would take a hit. You could even accidentally pick up slaves if you scooped up an escape pod from an enemy ship (and there was no way to free them, or hand them over to the cops). Open Source Remake Oolite fixed this by offering a small reward paid out from the survivor's insurance policy instead, and occasionally a bounty from the local police if they turn out to be a wanted felon, but you can still do it anyway if you feel like being a dick.

Webcomics

 * In the Terinu universe, the hyper-advanced Varn Dominion used slaves a great deal, but it was regarded as culturally necessary since their gods had declared they were the Master Race and deserved to rule over the lesser races and have their every whim catered to. Five hundred years later, the good guys' successor government permits the use indentured service as punishment for criminals (with one Jerk Ass Protagonist declaring it was "Cheaper than letting them sit in a cell and eat up public funds"!), and just good old-fashioned corporate evil as isolated industrial facilities bind their workers through indenture and selling their souls to the company store.

Western Animation

 * An episode of Futurama has the crew enslaved on an Egyptian analogue planet, where thousands of people are worked to death for laughs to build huge monuments and tombs. Bender gets himself named Pharaoh and takes it up to eleven.
 * In another episode, Hermes and LaBarbara Conrad unwittingly vacation at a forced-labor "spa".
 * In Teenage Mutant Ninja Turtles, Krang is the proud owner of the Technodrome, with all the Mecha-Mooks he can use. He and Shredder still force Bebop and Rocksteady to do all the cleaning work around the Technodrome, even though they are lazy and incompetent enough that it would seem more efficient to have the work done by robots.
 * The SpongeBob SquarePants Movie

Other

 * Many people just want the handmade version, even if they have to make it themselves. There are TV shows, books and even art projects all about doing things the "old fashioned way" or "as they did back in ___". Oddly enough, people are using 3-D printers to make hand tools, overlapping with Schizo-Tech.
 * Cosplay is a good example, most cosplayers will make their own costumes. Ditto Goth, Gothic Lolita and other "do it yourself" fashions promoting hard work and original looks. They will mock those whose hardest work is swiping the credit card.
 * Cooking is another. The Fifties promised us a Jetson's kitchen complete with Food Pills. Many of the "labor saving devices" never really caught on, except the blender and food processor. We know more about diet now, many people shun processed foods for their high sugar and fat content. Many people today prepare their meals with ordinary kitchen utensils and hard work (and food grown locally from small farms).
 * An interesting historical case: Ancient Greece. Towards the later parts of its history, this society seemed to be teetering on the brink of an industrial revolution, but never quite made the plunge, instead sticking with slavery and other traditional, labour-intensive methods of production. Ancient Greece had a great deal of scientific thinkers, the capacity to build complex mechanical devices, and even developed a simple steam engine. The steam engine especially, if developed further and perfected, could have been used to simplify a lot of labour-intensive jobs, as it was when the Industrial Revolution finally did roll around. But the Ancient Greeks saw it as nothing more than a curious toy.
 * Those that did think the steam engine was great tended to not be taken seriously. One guy was pretty sure that Hero's Engine could be used to predict the weather. Given that the boiling point of water varies depending on air pressure, and that quite a bit of the weather is dependent on moving high/low pressure fronts, he was probably actually on to something.
 * It's wise to remember that a steam engine requires fuel, and the truth of the matter really comes that in that day a human life was cheaper than the wood.
 * Hero's nothing. The Byzantine Emperor Justinian (yep, the very same Justinian who's most remembered for codifying the Roman Law and Belisarius conquests) was a bit of a tinkerer and it's said that he'd once built a reciprocating steam engine that he used to power a small model boat. Yes, the steamship was actually invented 1200 years before Robert Fulton. Justinian hadn't such ships built for the very simple reason: a common galley was much cheaper—and good enough for the time.
 * Consider also the medieval Chinese, who invented so many amazing feats of chemistry, engineering and metallurgy yet somehow were eclipsed by the western European nations and remained a bit of an industrial backwater for hundreds of years. Though much of this was cultural, as Confucianism taught rigorous adherence to the status quo.
 * Anthropologist Jared Diamond goes into this at great lenght in Guns, Germs, and Steel. I can't summarize it all here except to give say that in his view all human development basically hinges on your geography and every factor which follows that. It's really quite interesting.
 * Only he's a biologist (biophysicist and physiologist to be precise) and ornithologist by his main published body of scientific works. Anthropology is something of a hobby of his, and his anthropological works are hotly disputed.
 * Taking advantage of their food being very heavily standardized, McDonald's once experimented with a robotic kitchen, going so far as to build a Hong Kong outlet that used one. They scrapped the idea, but not the outlet, when the construction and maintenance turned out to be far more costly than employees. Their one fully automated outlet is still there, as a minor tourist attraction, but building more isn't worthwhile with today's technology.
 * Autoloaders for tanks and artillery free up some room, and save weight (for artillery anyway) but are notoriously unreliable. With one you only need 3 people (driver, commander, gunner), not 4 (the loader) and any weight saved can be used for extra armour. During the Cold War the Russians had auto-loaders in their tanks. The US Army never used them, even on the M-1. Why? The auto loader added weight and complexity and a 19 year old with a strong right arm was faster than any auto loader. As for the unreliability, the Russian auto loaders were famous for catching the gunners sleeve and trying to load his arm, some times it did. They do see use in NATO artillery, and large-calibre autoloaders can easily outload humans (6/2 rounds/min rapid/sustained for the manual loaded AS-90, but 10-13 rounds either way for the auto-loaded Pz H 2000).
 * Not to mention that the 19 year old is a lot more versatile than any autoloader, he can help you change a tread, watch your back while you make repairs, or fill in for a comrade if they get incapacitated. Try to get an autoloader to do any of those things!
 * Which is exactly what one 19-th century Russian general said about the machine gun: "Mitralleuse is in fact an automated rifleman, which is bulky and has to be taken care of. Human rifleman, on the other hand, can take care of anything he is ordered". It should be noted that he considered machine guns useful in special conditions, namely, when you are limited in manpower or space. Such conditions included ships and colonial expeditions. Cue the Maxim gun and two World Wars...

Break time's over! Back to the spice mines, worm!