Sure, the GM authored the world. Or perhaps some professional setting maker did (at least partly.) No one is eliding the matter, nor this being the case make what
@Manbearcat said inaccurate.
Who said anything about
@Manbearcat being inaccurate? Not me.
pemerton said:
Let's put it this way: in a story in which a character is apt to find incriminating papers in a safe, why wouldn't how skilled a thief the character is, and how strong the safe is, not shape the fiction?
Because the strength of the safe or one's skill in picking locks is in no way causally connected to the contents of the safe. Lets say one character have excellent skill at smashing locks and another have mediocre skill at picking them. Why would which of them manages to open/break the lock have any connection to what's behind the lock?
<snip>
Fiction can be sensitive to such things, but this approach muddles completely unconnected things together.
What is getting muddled together? And what does in-fiction causation have to do with the relationship between characters and what is at stake in a situation?
In Burning Wheel, if my PC has a high skill in Lock Picking, then it is more likely that my PC will get what they want by picking locks, than is the case for another PC whose skill in Lock Picking is lower. This is not a model of how causation works in the fiction. It's not a model of anything.
REH's Conan is more likely to achieve his goals, as protagonist, by fighting than is (say) JRRT's Frodo. In Burning Wheel, if I want to play Conan I need (among other things) a high score in fighting. If I want to play Frodo, I need (among other things) a high score in Perception. And if I want to play Sam, I need (among other things) a high score in Cooking. That's what makes it more likely that my PC will get what he wants - helping his friends endure their struggles - by cooking for them. As it happens, my knight PC Thurgon has a passable rating in Cooking. In building the character that way, I'm not just establishing a state of affairs in the fiction
that this guy knows how to cook. I'm also sending a signal about my character:
I aspire to achieve things by cooking.
Of course, if the opponents are tougher, then achieving a goal by fighting them will be harder (for Conan, or for anyone else). If a situation is more complicated or obscure - whether literally or emotionally - than it will harder for even an astute person to achieve their goal by understanding it. If all there is to cook with is what can be scraped together on the trail; or if the tastes of those I'm cooking for are so jaded that nothing but the finest cuisine will move them; then even an experienced cook will find it harder to achieve what they want by cooking.
There's nothing muddled about any of that.
I've never built a lock-picking character, but one of my friends I play with did once. Just like the examples I've given, that sent a signal too, that his character aspired to achieve things by picking locks. There was no muddle.
In such situation in Burning Wheel, how you determine 'the DC'* of the safe opening check? Is it based on the quality of the safe or narrative likelihood of the papers being in there, or something else?
(*I don't remember what the BW equivalent is actually called, but I remember that the mechanics are such that the odds scale way more steeply than in D&D, so GM's determination affects the odds drastically more.)
For each skill, there is a list of obstacles. The obstacles for lock-picking are based on the quality of the lock. Whether the test to open the lock could be augmented by (say) Incriminating Documents-wise; or whether the GM would just "say 'yes'" to the opening but call for a check on Incriminating Documents-wise when the contents of the safe are inspected; or something else; would depend on further details of the situation: how it was framed, and what the Beliefs of the characters are.