Fantasy kingdom where Only Royalty Can Do Magic but the royal family is so promiscuous and polyamorous and generous in their interpretation of what counts as family (“Your second cousin’s niece’s husband counts as family by marriage! Absolutely!”) that the whole kingdom is Technically royalty within like. Two generations.
You’d think this would wreak havoc with succession claims but actually once they realize everyone in the kingdom can do magic and therefore everyone is royalty and theoretically fit to rule they decide the only sensible way to pick is to vote on it and accidentally invent democracy. They just have to be careful to keep calling the person they elect king bc no one’s entirely sure what would happen with the whole magic thing if it figures out they’ve rules-lawyered the whole thing.
There is however a whole department of very beleaguered court scribes who have to work out what everyone in the whole entire kingdom’s appropriate titles and rank are because the magic can get very unstable if you don’t know you’re royalty, which includes knowing the specifics of your title. This was supposed to be so that lost princes and princesses could have very dramatic reveals where they discover they’ve had magic all along but will never control it unless they accept their destiny and go to court to learn who they really are but now it means that whenever you forget your title your cleaning spells go on the fritz and you come home to the mop attempting to scrub the ceiling again.
A neighboring kingdom writes requesting a family tree be shared with them for their own records and diplomatic purposes and the court scribes write back “Respectfully, the royal family tree takes up an entire basement and cannot be provided via post”










