"Sensible precautions"? Let's hear more about those! That's the entire point of this thread! Brainstorming how different worlds would work if mages had taken over and brainstorming precautions non-mages could take to prevent that. Please, go on!
Let's see...
- Have guards, and actually treat them well
- Honestly just treat people well in general, to cultivate a reputation of fairness (though you must avoid being known as soft: seek the people's love, but make sure they know not to cross you)
- Have money and people who depend on you to get paid
- Patronize others, particularly middling spellcasters who can do the flashy explosion magic but not necessarily the tricksy magic†
- Keep more-limited spellcasters (especially clerics of trustworthy, prosocial deities) as retainers to protect you†
- Secure the loyalty of the populace, or at least the bureaucracy, by treating them with respect
- Restrict access to repositories of knowledge
- Patronize education institutions so you can influence their curricula
- Support sustainable environmental practices†
- If necessary, establish a rapport with a selected set of warlock patrons, so they won't support overthrowing you (note, not the same as becoming a warlock for them! You can come to agreements without becoming a Warlock!)†
- Keep the army and other military types on your side, and suppress large-scale mercenary activity
- Monitor and control the flow of relevant materials and tools so you can limit access to things that could threaten you
- Pass laws controlling the behavior of non-state-employed spellcasters, and exercise swift but fair authority over those who are state-employed†
Worth noting, other than the ones marked with a dagger, all of these
literally did happen in Medieval Europe. Most of the ones that
are so marked are pretty reasonable basic things, the equivalent of taking away the katanas if the samurai class or trying to be a pragmatic but enlightened ruler.
You're mixing up Charm Person with Suggestion. So long as the person that you cast the spell on doesn't notice that you cast it (ala Subtle Spell), they don't know that they were Suggested. A Sorcerer with Subtle Spell could use Suggestion on a monarch without being noticed (so long as there isn't a Detect Magic spell up, which, again, would require another mage to cast).
While you are correct that
suggestion does not necessarily reveal itself...the suggestion provided has to actually be reasonable. That's not going to let you control very much. At all.
Suggestion can be very useful, but it isn't actually mind control, and you
will run into trouble if you mistake it for being actual mind control.
I think that mages would be at least as likely to be power-hungry as typical humans are.
But a significant number of humans
aren't power-hungry. Many just want to live out a life without any desire for power. Even amongst those who do want power, they almost always want it for a
reason, not for the power itself. E.g. the power to protect yourself or your loved ones, the power to heal someone dear to you who is sick, the power to earn enough money so you can just live however you want for the rest of your life, etc. Only the truly narcissistic desire power solely for its own sake, and it is not easy for such a person to just
become a powerful spellcaster. See below; narcissism does not lend itself to accepting
servitude or long-delayed gratification, but both things are required for most spellcaster classes.
And, again, I don't think it would be easy, at least not for individual mages. It would take time, trial-and-error, and the combined efforts of different people (royal bloodlines, aristocracy, religious institutions, etc).
Okay, but the more complicated and long-running you make it, the more you pull it away from "inevitable" and toward merely "plausible." You're already talking about having an existing social hierarchy and entrenched aristocracy ("royal bloodlines, aristocracy") and committed dogma that is very likely to oppose such concentration of power ("religious institutions"), and all of this coming from constellations of people across multiple generations. That's no longer a clean, slam-dunk "the power will
always accumulate in
this way and produce magocracies." Instead, it's at best showing that there would be a pressure here, a power bloc (or rather several such blocs) we don't see in our world.
But your reasoning is faulty, because you are reasoning from "if we inserted this power bloc into our world
and changed absolutely nothing else, it would take over." It is that assumption right there, the assumption that "all else being equal," that leads you astray. Because all things would NOT be equal. We cannot assume that the body develops no resistance in a world that
always had this additional threat.
Survival of the fittest. Power begets power. Unless there are enough of those "sensible precautions" you mentioned earlier, mages can and would take over because even though most mages might not be powerhungry, the ones that are would be able to take power.
Social darwinism is well debunked at this point, so basing the core of your argument upon it seems unwise.
You're correct that power often leads to accumulating power, but you neglect the
conditions required for power to come about in the first place, and thus the restrictions on the path that might pull things away even before things get started. So, for instance, you have handwaved the "wizarding depends on a societal infrastructure that permits not-directly-productivr academics," which will already have an entrenched power structure to it, by rather airily saying that "oh people will just pursue Sorcerer or Warlock instead."
But what do those classes induce? Sorcerer isn't something you can just
learn. It's an innate power. You have spoken disparagingly of people talking about not-defined-in-book ways of opposing magic, yet you base your argument in part on not-defined-in-book ways of
gaining Sorcerer levels. As the fluff text explicitly says, "No one chooses sorcery; the power chooses the sorcerer." So we shouldn't make any arguments which depend on being a Sorcerer, nor on feats, since feats are only present by DM approval and NPCs definitionally need that approval to exist in the first place.
But Warlock suffers exactly the same problem as Cleric and Druid, the "external authority" issue. That is, a Cleric in 5e that gains temporal power is, properly speaking, either ruling as a proxy for their church, or as a proxy for their deity. Tyrant-spellcasters would have to deal with the consequences of the religion they've ties themselves to, and one of those things is that religions which are likely to have large numbers of loyal followers
are not likely to be religions that support tyrants. Most popular religions are going to be at least vaguely Good-aligned, because most people recognize the social utility of joining a group that tells its members to be nice to each other. Further, defiance is likely to draw the ire of one's superiors, be they mortal or divine, and all organized religions worthy of the title police their own and take very, very dim views of deceit and power grabs within the hierarchy...especially if there's a
god at the head.
Druids, if anything, have it
worse because their lives are actively inhibited by the spiritual commitments they make. Unlike Clerics, who have no special requirements in behavioral terms unless their deity opts into it, Druids specifically have their very lifestyle dictated to them. They aren't
allowed to engage in certain behaviors associated with "civilization," most notably wearing metal armor or using certain kinds of weapons. Yet they also don't have the luxury of looking for a patron that they would prefer to serve, e.g. one with a compatible or exploitable ideology, because
there's only one Nature. They're simultaneously more limited in behavior
and more limited in options, so there's no way a Druid is gaining such unlimited power without some real special circumstances.
(Note that these problems are over and above the problem of needing societal development in order to rise to power; the developmental-dependency is lower for Clerics and Druids than for Wizards, but it is definitely not zero.)
Which leads us to Warlocks. Warlock does avoid the problem of availability/societal development dependence: in theory, as long as there are powerful beings, there can be Warlocks. However, this arrangement is
even more contractual and controlling than the Druid! You are literally signing over authority to your patron. They can't just pull the plug like they could with 3e Clerics, but your patron can and will punish you for breach of contract. You're pretty clearly under obligation. Further, Warlock is by far the
weakest of the full casters. It cannot ever cast more than one of its level 6+ spells each day, and while it can cast a comparatively large number of 5th-or-lower spells, it cannot
know more than a tiny handful thereof, radically reducing its power potential. The Warlock is simply not capable of reaching the phenomenal cosmic power you speak of as a requirement for your predicted "casters will inevitably take over." Their severely restricted spellcasting forces them to be incredibly economical, and being incredibly economical with your power does not bespeak of being able to throw one's weight around willy-nilly!
So...yeah. The Sorcerer cannot be opted into, it's a roll of the cosmic dice whether you even can do it or not and even if you can you're much more limited than other spellcasters. That randomness added to the complexity you already admitted above pretty well sinks any chance of true power accumulation by such a person. The Warlock is
even more magically constrained than the Sorcerer, while also having patron interference and expectations of deference, and having to keep the true source of one's powers a secret or else risk immediate betrayal/opposition, adding yet further complications. Druid and Cleric come with all sorts of extremely limiting baggage and don't directly contribute to rulership stuff, and Wizard (as noted) depends on an already well-entrenched social order that permits relatively well-off people to spend their days holed up in s cloister and doing academic things for 20 years.
So, in sum, the forces you speak of are not nearly as inevitable as you imply, particularly if we account for them being part of the world from the beginning; the classes involved have several limitations, internal and external, which you are neglecting; perfectly ordinary measures taken to forestall others gaining power (many with actual historical precedent) would work quite well to mitigate this pressure; and you've largely pinned yourself to the Sorcerer as the class to get the job done, but that's the one class that
cannot actually be relied upon in any meaningful way.
There is, of course, one debatable exception here: Bards. But what were bards considered IRL? The mythic ones had great power and zero desire to rule because they had more important things to do, like learning the true secrets of existence or satirizing the hell out of crappy kings. And the modern(ish) ones were widely seen as morally-destitute libertine layabouts....a reputation shared by many musicians and movie stars today. And how many modern actors or musicians go for fantastical power? Very few, despite explicitly having devout followings and the like.
Astronauts do better than actors in most cases. And they are also a "spells known" class, though slightly less limited than Sorcerers.
So...yeah. Bards
might be able to pull this off. Charisma, flexibility, somewhat lower limits, less need for formal training. But they've got social bias against them and share many of the problems that Wizards have with just not
getting much out of temporal authority other than a big headache.
