Going to use this post to discuss Framing and Consequences and try to put together a post that will help you understand why the bold word here is a category error and why there was no violation of The Czege Principle.
The word you should be using is propose. Author means fiat. You're stipulating a thing without resistance or recourse to dispute it. That is NOT what is happening in this case. The player is making a proposition and we're going to the dice to find out if (a) that proposition turns out to be a solution to his problem or (b) something else.
Basic play loop:
Step 1: Player proposes some fiction.
Step 2: RNG is successful.
Step 3: Player's proposal becomes fiction.
Regardless of what came before, the moment step 3 gets here the player has authored the fiction. All the RNG is doing in step 2 is picking whether the player got to be the author this time around.
That's not a very good account of the basic play loop of a player-agency-supporting RPG, because it assumes what is false, namely, that checks always succeed.
Here's a better account (it's more generic than
@Manbearcat's because not particular to any single mechanical framework):
Step 0: GM frames situation
Step 1: Player declares action for his/her PC - this is a proposal for a change/addition to the fiction as it pertains to the protagonist PC
Step 2a: Either everyone at the table goes along with the player, in which case we're back at Step 0 with the framing further developed, or someone - typically the GM but maybe another player - calls for a check.
Step 2b: Whether by express GM explanation at this point (or perhaps explanation from another player if they are the one who forced the check), or whether it is implicit in the fiction as established so far, there is a sense of what will happen if the check fails.
Step 2c: The check is resolved using the appropriate mechanical process.
Step 3: Depending on the way the resolution panned out, the fiction changes in one of the following ways: the fiction contains the player's proposal; the fiction contains the player's proposal plus some of what had been flagged as a consequence of failure; the fiction contains only the consequence of failure. Whatever the nature of the change, we're now back at Step 0.
This is consistent with [urlk=[URL]http://www.lumpley.com/hardcore.html]Vincent[/URL] Baker's observation[/url] that I've already quoted once or twice in this thread:
Roleplaying is negotiated imagination. In order for any thing to be true in game, all the participants in the game (players and GMs, if you've even got such things) have to understand and assent to it. When you're roleplaying, what you're doing is a) suggesting things that might be true in the game and then b) negotiating with the other participants to determine whether they're actually true or not. . . .
So look, you! Mechanics might model the stuff of the game world, that's another topic, but they don't exist to do so. They exist to ease and constrain real-world social negotiation between the players at the table. That's their sole and crucial function.
Different mechanical systems produce different versions of Step 3 (ie how do different resolution systems lead to that range of possibilities being actualised in game play?). They also produce different sorts of pacing and dynamics (ie how often do the protagonists succeed at all, or completely?)
What they have in common, in these sorts of RPGs, is that they allow player proposals to become part of the fiction without any capacity for the GM to "block" that by relying on hitherto-unrevealed, unilaterally-established components of the fiction.
And to relate this to the Czege Principle: the player is not both posing the challenge and authoring the solution. The GM contribute to framing (see Step 0) and another participant has established the adversity (see Step 2). The player is not just free-narrating his/her way through the fiction.