AbdulAlhazred
Legend
I’m not talking about a single example where it works. I’m talking about it always working with the game.
I would contend that Dungeon World 'always works'. Its a simple loop of play, the GM describes a situation, and then asks the players "what do you do now?" If no player wants to declare a character action (always in character, you never name a move) then the GM makes a move, usually a soft one. If a player does declare some action, then their character does that, assuming nobody at the table thinks its impossible or genre breaking, etc. and noting that players don't have an arbitrary remit to just make something up (IE a piece of equipment or an NPC or whatever). The GM now decides if this action is a formal 'move' or not. If not, then the PCs carries out the action. If it is a move, then the rules for that move are followed. Once the action is resolved, the GM may describe any additional new fiction if it is needed (maybe an entirely new scene) or simply ask for more player actions, possibly naming a specific character who should get a chance to act next, or just an open invitation. Again, if nothing happens and nobody acts, the GM once again makes a move.
Now, there can be some mechanical grey space there. Is an action a move? Which one? There are some fairly generic moves, like 'Defy Danger' that GMs could probably apply in a LOT of situations, but its subjective. The GM introduces most of the actual present fiction of scenes, so has a lot of leeway there, but as I said in an earlier post, must use the agenda and principles when doing this. The point is, there's always some sort of clear forward way that the game can proceed without any mechanical problem. You never need to make up rules in DW, although GMs CAN declare a new kind of move, like if a PC got a holding you could have them check for income or send out patrols, etc. So, my perception of Dungeon World is that there's really no point where it can 'fail to work' in the sense that someone has to make up a new game process to cover a situation that was not considered by the rules.