hawkeyefan
Legend
No, it's not. The poster who described dice as having whims wasn't pretending to be describing a literal truth, but was using "whims of the dice" as a metaphor for "random chance"; that's not playing a semantics game at all. I'm asking how "The DM Decides" removes player agency but "The Dice Decide" doesn't; your example didn't touch on player agency, by my lights, and I'm trying to determine if you're maybe using it to mean something radically different from what I do.
In the example given, 1-3 GM narrates and 4-6 player narrates, the dice may grant the player the ability to decide what happens as a result of the action. If they roll high enough, the player has the agency to narrate what happens. They most likely would narrate some form of success for the action in question.
If the GM decides, he's likely going to narrate some form of failure or perhaps success with setback or similar. Whatever he decides, the GM is narrating the outcome, not the player, so on a 1-3, the player has no agency.
Now imagine on a 1-6 the GM decides. If that's the case, where does the player agency come into it?
If things are always up to the GM, then the players cannot know the chances of success for any action they take, not unless the GM decides to share his reasoning or his judgment with them in some manner (perhaps he says "this will be a DC 25 persuasion check" or even just "this is going to be very difficult to pull off" or something similar). And it's also possible to get very used to a specific GM and how they tend to handle such things to the point where players start to become comfortable about gauging their odds for in game actions.
None of this changes the fundamental fact that if the GM can always trump the rules, then player agency can effectively become zero under this system.
There may be times where it is perfectly reasonable to restrict agency....several examples have been given, whether based on genre or the established fiction, and there are probably others we could come up with, as well. I don't think that anyone here would say that such GM judgment is always bad or anything like that.
I think it's just more that rules that so heavily rely on GM judgment in this manner typically will either not offer as much player agency, or can be more susceptible to an arbitrary reduction in such agency. They also tend to lend themselves to potentially unclear situations such as may have existed in the OP.