Content authority in Burning Wheel is distributed. For players, it is mediated via tests - typically Circles tests (to have one's PC meet a helpful NPC), Wises tests (to recall some useful bit of information about a place, thing, person, etc), or other knowledge/perception type tests. Here's an example of the latter (I've posted two accounts of it, because each highlights some slightly different features of the context and play:
Apparently I can't quote quoted text, so copypaste will do.
"
I look around the room for a vessel to catch the blood was enough to establish adjudicable fiction."
Same as in any other game. In some games, the GM may call for a check to search the room to find a vessel. Did you roll high? You found something. Did you roll low? You didn't. In other games, the GM may simply say they find something, because
finding a vessel is not, in itself, all that interesting because there doesn't seem to be much of a time crunch or any other threat involved that would make finding or not finding a vessel to be interesting; the
actually interesting part of that scene--beating the assassin to the room--was already past and the guy was dead. And chances are at least average that one of the players has a waterskin on them that could be dumped out and used as a vessel.
"This is an example of what I mean by letting the action declaration be resolved without having recourse to the GM's pre-authored notes/setting."
Few, if any, GMs are so trapped by their pre-authored notes that they would look what they previously wrote and say "sorry, my notes don't say there's a cup or jug or anything like that in the room, so y'all are SoL." Unless the room had been previously established to be
completely empty, of course. In which case a roll wouldn't do anything.
In a roundabout way, this does answer my question, which was: who gets to decide if a thing exists? The answer is "nobody." You apparently
have to have the dice tell you if it exists. You can't just make it up. Even though Joachim was recuperating in a room in a wizard's tower, which strongly suggests the presence of cups, bowls, vials, and the like, so basic sense tells you should have at least
one vessel in it.
So, returning to the secret Kobold fighting ring - does it speak to player-determined priorities? In which case, GM, knock yourself out. If not, then why are you talking about it?
That's far too self-centered for my tastes. How do the players know that the kobold fighting ring won't be something that interests or angers them? How do they know that it won't tie into their interests further down the line?
The argument between Thurgon and Aramina, as I have said, was about whether or not she would mend his armour. Thurgon's armour was damaged (I would guess down a die of protection, though I don't recall the details); Aramina has Mending skill (and Thurgon does not). I've told you the context, and the Beliefs that were in play. As per the notes I found in an earlier post, quoted just above, Thurgon also persuaded Aramina to get some information first.
But it was not an attempt to control movements, nor was it about "personal autonomy". And the discussion was about the mending of the armour. That, more than the other aspect, is what has stuck in my mind for the years since the actual play of the episode.
If you can't recognise how the Belief Aramina will need my protection might prompt Thurgon to request that, before they go to a dangerous place, she should at least mend his armour, that's slightly odd to me, but whatever - it doesn't mean that my recollection and account of what actually happened is wrong. Likewise, if you can't see how the Belief I don't need Thurgon's pity might make Aramina bristle at Thugon's request, given the context that is motivating it, ditto.
Oh, well, in
that case you took what could have been an interesting argument about one person wanting to strike off on her own without someone else to protect her and made it into a dull and pointless request to mend armor (pointless because I'm sure there were other smiths he could go to).
Awesome.
You're admitting here that it's actually what I was saying it was about. She wanted to go somewhere. She didn't want his pity. He tried to stop her from doing what she wanted to do without (what he felt was) the proper equipment. This is literally about trying to control where she went. Presumably, since she didn't want his pity, he was also being condescending to her in some way.
The argument about equipment happens in every game where equipment is a thing.
The argument about trying to prevent someone from going where she wants to go until she satisfies his conditions is about one person controlling another person.