Castulia has duels? I LOVE DUELS! So dramatic. So stupid. How do those work here? Nobility only or do soldiers join in? How common are they?
While duels are not quite the prominent feature of Castulian culture that they are of the Iskendi one, they are present there also, yes! There’s no real rule against anyone participating, as they’re kind of “officially” frowned upon anyway, so the law only regulates them so much.
The main features are that anyone is free to turn one down, and in some situations this is socially the obvious thing to do. It is quite uncommon for people to accept duels proposed by people of significantly lower social class, for instance, because this is dignifying the challenge, to some extent. There’s a lot of implicit rules about what acceptance or rejection implies.
The duels themselves are, unlike the Iskendi kind, usually resolved before anyone draws. One or both parties apologizes, with or without losing some face, end of story. When they do happen they are always technically to first blood—that is legislated. People sometimes die anyway, because weapons are sharp and people can die from getting cut by them, especially if the cutter is either poorly trained or malicious. The penalty for killing someone in a duel varies, and can depend on factors like: who was the challenger, what was the dispute, can malicious intent be proven, how skilled a duelist is the survivor (soldiers, for example, might be expected to control their damage better), and so on.
What weapons are used is decided by the participants. As long as everyone agrees, anything melee goes, but you can’t like... bring a bow or anything. There have been a few recorded instances of magic being used in duels, but for obvious reasons this is vanishingly-rare.
In general duels are quite uncommon, especially in the central Empire. Closer to the borders, their symbolic value may sometimes outweigh considerations against them, and more than one governor has used a public duel to make a statement about who’s in charge.