I do not know from taxes in the real world. I don't know accountancy. I happen to have read a couple of engaging fics lately where a character was an accountant - Coulson and Cold I've seen written that way. So I know there are badass things to do when you follow the money and/or hide the money for a living.
But how the heck did Roman taxes work? Probably lots of different ways, since Roman covers a heck of a lot of time and geography. I read one web page about it and realised I need new vocabulary and a larger book.
And how did taxes work in the middle ages, or right before and after the Black Death? Whenever I get to that bit in the fantasy AU where there are sticks of Cure Disease that work then the whole of history takes a sharp turn. That would change all kinds of everything. What even were taxes then?
And then there's the thing where I sat down to write a medievalish fantasy using my vague knowings from those three textbooks I read, but I keep being distracted by knowing that, with those three agricultural spells, crop yields would be much closer to modern than that, and could support a population level way up near the industrial revolution. You get more food from less land with less effort, you need fewer people spread out doing the farming, you get more people more concentrated, there's room for education and specialisation, innovation happens.
A world where magic works is a world where plague and famine are not major factors, unless mages are weird somehow.
It ought to advance further with fewer setbacks. Even if most of that advancement is new spells. A magic using society shouldn't look medieval for long.
So what does that do to the taxes? How did tax law evolve, why did it do that, and how much had to do with advances in information technology like fancier bookkeeping?
And then, of course, I've skipped some important questions, like what size of what kind of powers are even collecting said taxes, and then I need to figure what they're even doing with them.
And all this I need to know because my character wants to roll up and set up a trading business, and what would that even involve? Do they have to register a unique company name with companies house? since when is companies house a thing? what's a limited liability company when it's at home anyway?
... the only fiction I've read where it focused on trading, either the characters were caravan guards, or the dude learned everything he knew by being a waiter in a coffee shop. They were not especially legally focused, is what I'm saying. And I don't even know enough to write either thing. Though I can guess which bit of the library to find relevant books in.
And Law... does anyone do conlaw the way there's conlang, or is that just international comparative law? I mean there's a lot of countries, there's got to be a bazillion ways to rule on anything. Picking one particular part of the world to base your alternate universe on could mean just using a law system that is not usually in English and/or differs from American TV Stereotypical in some significant respect, thus making it all spooky new. Or you could pick a legal ruling that could have gone either way and tip tilt. But that's a whole huge thing.
I mean mostly even fiction full of rogue characters doesn't get into too much detail about what laws precisely they're breaking. Nicking stuff and killing people seems fairly self explanatory.
But because my brain is a weird place, one of my characters just turned up to take possession of their nice new plot of land, and they discover it no longer has topsoil. That seems like a law courts sort of a thing, there. Like, excuse me, but we were awarded land, not land minus the top four inches. And all the plants went away with the previous owners, leaving the new guy with a serious erosion problem along his riverbank that's going to annoy the neighbours fairly swiftly. What kind of law applies there? Just because a magic user can make the plants get up and follow them doesn't mean legally speaking they should, is what I'm saying.
But I am not only not a lawyer, I have zero books read that could be even vaguely relevant. I only even thought of it cause I was house hunting and one new build had a dirt around it that did not feel like garden and apparently was failing to support even grass, and mum said topsoil probably sold for moneys before they built there. And in a 'verse where magic like Create Earth and Purify Earth can make topsoil out of nothing (which is absolutely a huge big deal, they can terraform bare desert i they feel the need, topsoil usually takes between decades and centuries and they can make it in seconds, how is it rpg magic never understands which bits it can do are huge... er this is a lot for a bracket what was I talking about...) ... oh, yeah, if magic could replace the soil in a jiffy, maybe the law thinks it's as trivial as taking your carpets with you. Or maybe it's meant as a deliberate challenge for the new residents, lets see how well they can put their place in order. Except only half the team arrives in one piece, so story ensues.
I need to know property law and who can own land and how, because I vaguely decided the place was a park but the keep has given it to the new couple, but that's, like, enclosing the commons, or something, unless the keep was letting the town wander around a lady's private garden, and either way, big changes. And I need to decide how Morgan even got the land. How does anyone get land? I decided only women own land, because why not, and the difference between a woman and a Lady was the difference between leasehold and freehold, and you have to qualify to be a Lady by being able to do some basic magic. That's an interesting set of starter conditions. But then I need to actually build law about that. I mean, may e the land is always stripped, so a new Lady proves she can Hold it all by moving in and making it alive? But that's a hell of a waste of earlier effort, that doesn't seem quite right.
And of course this is all the questions I know I need to ask myself. The ones I don't know I don't know will come back to bite me, I'm sure.