At least, so sayeth the thoroughly indoctrinated peasant in Monty Python and the Holy Grail. He was very well versed in Marxist ideology, that one, if a little hazy on the details of how stuff would actually, you know… work.
Which is a problem with a lot of fiction, particularly fantasy (since it tends to deal a lot in “evil ruler oppressing the peasants” – I AM being repressed by the way. Every time I try to type, a cat wanders over the keyboard and forces me to undo the kitty-typing before redoing what I was trying to say – but the more generic entries and even some very well selling ones seem awfully vague about how the oppression actually happens). Sarah and Dave, of course, completely fail to fall into this trap. As does Terry Pratchett, who uses the stereotypes for laughs in (among others) Lord Vetinari who doesn’t so much oppress (unless you’re a mime, of course, but that’s more an amusing personality quirk) as keep the various factions more interested in beating the other various factions than anything else, the great lords of the Counterweight Continent (Lord Hong, Lord Tang, Lord Fang, Lord Sung and Lord McSweeney (yes, really) – mostly Lord Hong who tends to see other people as being so far beneath him they exist to serve his goals). Not to mention the politest revolutionaries ever, who still think they can make things work better than the people who’ve been living on and farming the land for generations (at one point Rincewind asks one of the local farmer-types what he’d want if he could have it. The man is unable to think of anything beyond a “better water buffalo”.)
So how does repression really work? It’s not something that happens because some watery tart hands some fellow a sword and calls him king. Nor is it something that just magically appears because the king/prince/whatever is eeeevile. Especially not in a fantasy environment where even with relatively common magic communications are somewhat spotty and your average farmer is mostly concerned with what his local lord is doing. More often than not, he doesn’t know or care what the king is doing – unless of course the local lord is telling everyone that the latest round of taxes are the king’s orders (which a smart lord will do even if they’re not – chances are no-one is going to get anywhere they can find out differently for a good long time, much less get back and spread the word). Now the lord’s taxes are a different matter… And the lord had best watch his back if he starts repossessing too many farms for unpaid taxes, or selling people into indentured servitude for unpaid taxes (aka debt slavery – once a common practice just about everywhere that had enough societal organization to have debt). That or he’ll find those productive farms are suddenly empty and the nearest sanctuary town is full of new residents all working their year and a day to be officially part of the town. Or the nearby woods have acquired a sizable population of bandits who show remarkable discernment in who they ambush.
There are still ways… One is to set pay rates and penalties in a way that ensures the unfortunates are drawn into ever-increasing debt. Then publicly pardon all debts every few years – it wins gratitude without ever addressing the underlying reason people were being forced into debt slavery. The ancient Mesopotamians were particularly adept at this. (Yes, history is a very good source for all of this stuff. There’s very little out there that someone hasn’t tried, particularly if it involves doing something unpleasant to someone else. We’re an inventive species that way – which may explain our reluctance as a species to leave everyone else the hell alone. I suspect too many of us are scared of what everyone else will do). Another is the path of the all-consuming religion, particularly effective if said religion involves sacrificing babies. Or virgin maidens (although this is a rather less secure quantity since the maidens in question will aim to cure their virginity as soon as widespread virgin sacrifice starts happening – which of course means that the evil priesthood would need to confiscate the girls and raise them in strict seclusion, preferably monitored by unhappy older women (they make the nastiest enforcers of social mores out) until they were old enough to count as a sacrificial virgin. On reflection, babies are easier). Both have been done, by (among others) the Aztecs and at least one African tribe. The Aztecs are better known, having made something of an art form out of human sacrifice. The Dahomey tribe was known more for quantity than interestingly unpleasant rituals. There’s also the ‘farming’ raid technique, where one raids ones neighbors and carries off the young boys (to be adopted and turned into one’s own warriors) and girls (for slaves, usually, and generally only the ones that are just about ready to start having babies), leaves as many of the women of child-bearing age pregnant as possible, and returns a few years later to repeat the process. Eventually the neighboring society collapses or flees, but until they do, the raiders get a good supply of whatever they need.
What mostly can’t be done is modern-style oppression – the thought police. In a fantasy world, unless everyone is using magic it’s not really possible to have one in four adults informing for the state (as was the case in many of the former communist regimes in Eastern Europe). There isn’t enough specialization to employ the clerks to sift through it all, much less act on it. The closest you can get is the religion that has people scared to think wrong in case they go to whatever version of hell your fantasy world supports.
In science fiction of course, anything goes. You can have an abusive authority controlling all the lines of communication (North Korea). If you’re working with a space station or other artificial habitat you have the added benefit of being able to control access to such necessities as air. What you can’t do is have all of this and an active rebellion on the same space station unless they’re being helped or protected by someone high up in the system. And then you’re getting into sticky politics rather than simply oppression (hint: all politics usually comes down to personal somewhere. Figuring out where and how and what the incentives are is the fun part).
And I’m still being oppressed by my feline masters and mistress. Her Fluffy Highness is cuting me because I haven’t petted her recently enough. That’s oppression, right?