Well then, I guess in the spirit of
@TheSword 's technically empty post...
When I hear you say "just frame a good scene"
@pemerton , I get very confused. I don't know what that means. You've described it as...basically just saying a scene happens. Absolute fiat declaration, no holds barred. I don't like that idea. That idea sounds like literally just telling the players, "You're doing this now, capisce?" That's why I see it as railroading; you are doing whatever you like, and the players can put up or shut up.
Well, yes and no. The yes is that absolutely you're saying "this is the challenge, what do you do?" The no is that the players have already told you what they want and you're framing the scene in relation to this. Can't be railroading -- the players chose this.
How did they choose this, you ask? Good question. Their characters have been built with strong hooks, so you hook those. Alternatively and in addition, you ask questions. And, finally, in many games, the players directly tell you what scene they want framed.
Take
@pemerton's examples -- 3 newly formed characters are knights in a chivalrous time, and have joined together in travel on the way to a tournament. They meet a young knight along the way that challenges them to a joust! This is the scene -- what are you going to do with this young knight? This speaks to the themes the players have established in their characters, and it follow directly from them telling you they are knights going to a tournament.
This is actually MORE keyed to player wants that a randomly generated encounter on the way to a tournament because the GM decided there needed to be a random encounter (either by fiat or by choosing to make a check). In D&D, the odds that these same characters, with the same drives and backstory, would meet a knight interested in a chivalrous joust is zero -- you're going to meet kobolds or goblins or maybe some rats. All things that have zero interaction with the characters or the premise of the characters.
The games being discussed by
@pemerton all feature requirements that the GM frame scenes or situations within very tight constraints, and it's immediately obvious to players if these constrained are violation. You can't railroad, because it would be clear if you framed a scene/situation that didn't align to the players' espoused wants -- you as the GM do not have that freedom.
When I pushed on that, you followed up with, more or less, "ask them what they want to do, then have that happen." This confuses me further, because I have explicitly and repeatedly said that I talk to my players
frequently about what they want. Between sessions, I ask explicitly. During a session, I prefer not to ask explicitly, in part because I feel that interrupts the flow of play too much, and in part because Dungeon World explicitly tells me never to refer to the
player, only the
character. (Principle: "
Address the characters, not the players") Instead, I go off what they've said before, patterns in the character's behavior, and how the player describes the character's current status/behavior/emotions, and if those things aren't obvious, I ask the player, "How is <X>? Are you scared, determined, unflappable? What are you looking for?" When necessary, I will resort to more out-of-character conversation, if hacking a new move or the like is required, but I try to keep that to a minimum so we stay focused on the fiction.
I don't know how you can claim to run Dungeon World according to it's principles and also claim that Rule 0 is part of the game or not follow what
@pemerton is saying above. Something is off, here.
Further, you have asserted that it is not true that the DM can do whatever they like. I had thought this was well-understood to be a literally universal maxim for any game that has a GM-like role, known as Rule Zero. A lot of people use it (and I would argue, often badly, but that's just me). Every DM can always override any rule in any rulebook, any idea from a previous situation, even their own previous precedent if they wish to. I emphatically do not believe they should, but I do not see how it is possible for you to argue that a DM, even in 4e or BW or whatever system you wish to suggest, is not (at least in theory) free to say, "Nope, that's not how it works this time." If you have an argument that Rule Zero doesn't exist for 4e (or BW, or whatever else), I'm all ears.
@chaochou neatly addresses this -- Rule Zero is not part of lots of games. You do not have the authority, as GM, to override the rules in Dungeon World without engaging in bad faith play. Essentially, if the GM does this, they are breaking the rules of the game.
I find Rule 0 to be emblematic of games where the concept of play is "the GM decides." This describes 5e to a tee, and so Rule 0 is necessary to make sure that the rules never prevent the GM from having the game the GM wants. In a game like Dungeon World, though, the point isn't to have the game anyone wants, but to find out what happens when everyone tries hard to get what they want. The fundamental purpose of play is different.
As for the "metagame" thing, I mean a WHOLE different ballgame from "shape the fiction as you wish it to go," which I guess you can call "metagame" if you like, but I personally wouldn't. What I'm talking about is: "okay, we know we rolled badly on that, so whatever he said, he was lying, that means we should act as though whatever he said is false even though there's literally no justification for us to do so, other than that we, as players, know that the dice were bad instead of good." To the best of my knowledge, this is an explicitly Bad Thing in Dungeon World terms, because it means thinking mechanics first rather than fiction first. It means thinking as a player, rather than as a character. And I'm absolutely not alone in having this problem; this was a big discussion on the old Google+ site for Dungeon World, and it's come up repeatedly on the Dungeon World subreddit.
Metagaming is a red herring. It's a boogeyman of your own creation. Literally, the GM is always responsible for metagaming in D&D, and it's just not even a thing in other games unless you're inventing it. You functionally cannot do it in Dungeon World at all -- everything, as you note, flows from the fiction. You can't "metagame" in Dungeon World because everything you know your character knows -- there's no player knowledge unheld by the character. Even on the mechanical side of things, this is no different than in any other game where I can play my character, deploy mechanical tools, and not metagame (like select a spell and cast in in D&D, or use a class feature when I want to, decide the timing of things on my turn, etc. etc.). In Dungeon World, aiming to use your best moves is still being in character because the character would want to deploy their strengths as well! It's vapor -- a specter of fear trained into you via the received wisdom of D&D with the blame misplaced -- GMs in D&D are the sole source of metagaming.
And I say this because GMs control all of the framing authority in D&D. Meet trolls? It's the GM wanting trolls to be unknown and special and their gimmick to work once again that's the problem, not the players. Change the encounter so it doesn't rely on the gimmick, and players can decide if their characters know about trolls or not however they want to. This is still playing your character, you just get to decide more things about that character rather than asking the GM for permission on how to play it.
Sooo...yeah. I explicitly, repeatedly consult my players. I constantly seek feedback and advice. I don't understand what it is I'm not doing that I'm supposed to be. And I don't understand how "<x event> just happens, deal with it" is somehow magically NOT railroading, just because you did a temperature check with the players--nor how that isn't "GM-directed" play, which you seem to dislike to a very severe degree.
You're still making all of the choices, though. You ask the players, then you prep, and then the prep is locked in as to how you imagined what the players would want would go. If you've asked your players what they want, and they tell you something about wanting to head to the Duke's keep to search it for clues to his impending betrayal, then you prep a keep and place clues. But, you decide what those clues are -- what plot points they lead to. You decide where those clues are -- they can be found here and here and here. You decide what obstacles are in the keep -- guards, traps, social encounters, etc. And then the players engage those, and if they declare and action that doesn't align, that action fails. Like, say, "I search the bureau for a clue," but you notes say there isn't a clue in the bureau, then the answer to this is always going to be "no clue there." You might dress it up, use some subterfuge with dice rolls to obscure this no, or just say it outright, but that action, to search the bureau for clues, will always and evermore fail to find a clue.
In the games discussed by
@pemerton, the same statement from the players leads to no prep, but instead immediately framing a scene at or near the keep, that leads directly to their player's stated wants and that frames an obstacle to that want. Whatever the players try to do in this scene, barring violations of genre, may succeed and establish new fiction. Perhaps, in a twist of fate, the players are near a bureau, and declare they are searching it for a clue. If they succeed, they find a clue, and, since they believe the Duke is engaged in betrayal, that's the clue they find! The GM can't do anything else. But, if they fail, then the GM can say they don't find a clue here, and guards are approaching, or that they do find a clue but it shows the Duke is being outmaneuvered and set up as a patsy to take the fall for someone else's betrayal. Whatever works well and fits into the fiction and the character's hooks.
This is a fundamental difference in approach, and, if you've run Dungeon World and don't see it, then I'm left questioning how you ran DW -- it appears you may have run a bog standard D&D approach with some different mechanics and had some moments of "huh" where you needed to use Rule 0 to make the game make sense. In which case, you missed the game.