Tell them the requirements or consequences an

This move is particularly good when they want something that’s not covered by a move, or they’ve failed a move. They can do it, sure, but they’ll have to pay the price. Or, they can do it, but there will be consequences. Maybe they can swim through the shark-infested moat before being devoured, but they’ll need a distraction. Of course, this is made clear to the characters, not just the players: the sharks are in a starved frenzy, for example.