There have been plenty of fantasy settings that have used the noble class has more rights then the commoners. In Katherine Kurtz Deryni novels an incident takes place where a noble of Deryni blood is found dead. It was common knowledge he raped young children. The King ordered 50 commoners from the area arrested and sentenced them to die for the crime. The Duke of the area tried to negotiate for his people's lives. He was allowed to save one the rest were hung.
Ugh, nonsense like that makes me glad I don't read fantasy novels. I doubt I could have restrained the urge to throw the book reading something like that. . .or if I saw it in a game to restrain the urge to shift the entire PC plot to assassinating the King in the name of justice and not care what the DM thought about derailing the campaign. If the book did not end with that tyrant king being deposed and preferably dead, I don't think I could read it.
One thing I have noticed about a lot of fantasy literature, including gaming settings, is that they exaggerate the powers of the nobility well beyond what they were in reality. Or more accurately, assume their
de jure power was their
de facto power and don't take into account that it's a big difference from granting somebody power on paper and them actually getting away with using that power and the common people accepting that they have that power.
One example I can think of is the Rokugan setting for the Legend of the Five Rings RPG & CCG. It's an Asian pastiche strongly based on feudal Japan with some elements of China and other Asian cultures thrown in.
In this setting, one right every Samurai (and most PCs are all samurai caste, if they aren't monks) has in that setting is to kill any commoner at their discretion, no trial or appeal, or even warning. A samurai legally can just be walking by, decide at a whim to kill a peasant, and pull out his sword and kill him and keep right on walking. It's been almost a decade since I've played, I think maybe they
might have to pay a token sum to their lord if the peasant wasn't one of their own vassals.
The setting materials, and the GM I played under, played this as completely normal and accepted by the peasants and a right that Samurai were very willing to use if they felt even the slightest bit disrespected or bloodthirsty. Peasants were reverent and fearful of even the lowliest samurai because they knew that they could die in the blink of an eye if that samurai had even a whim to do so, and there was nothing they or anybody they knew could do to stop it.
The problem is, historically, it was nothing like that. Yeah, samurai had a similar right by law, on paper, but that law ran into all kinds of problems called human nature.
Samurai who just arbitrarily killed peasants tended to be mobbed by that peasants friends and family, and in a realistic setting one lone armored warrior versus a few dozen commoners with pitchforks and hammers, that samurai would probably lose (unlike D&D except for a very low level Samurai). . .and to prevent further retribution from the next samurai or Imperial representative that came by, their swords would be broken and melted down at a local forge and the body hidden and buried.
Also, the control of the people wasn't as absolute as fantasy materials would make you think. Using the Japanese/Rokugan example, in Rokugan the Emperor's will is absolute and rebellion would be utterly unthinkable and the forces of the six great clans would be so strong that no peasant revolt could possibly end in anything but bloody failure.
In the real world, for 78 years, from 1488 to 1564 the Kaga province, as well as a portion of Okawa, Ise and Mikawa provinces were in open rebellion against the Shogunate as an alliance of peasants who were fed up with abusive behavior and monks who championed the idea of all humans being equal (and thus opposed special rights for the Samurai and nobility). You'd never see anything like that in a fantasy RPG, except maybe portrayed as ignorant and insolent peasants who would be quickly and brutally crushed.