GM: “It looks like there used to be a bridge spanning this chasm, but it’s long gone. All that are left are spindly-looking poles where the bridge once stood. They’re wide and sturdy enough that you can hop across, but it’s dangerous. It’s a long fall to the river below.”
Player: “I’m going to cross anyway, I’m nimble enough for it. With a running start I parkour my way across.”
GM: “Defy Danger with DEX, please.”
Player: “Oh no, I rolled a 3! I missed!”
While the obvious response to missing a roll like this is “you don’t make it across”, this isn’t an optimal result, both because the fall would probably kill the PC and the GM doesn’t have anything prepped for what’s below. The GM doesn’t want the player to completely fail, but there still needs to be some hard move. He draws a blank, so instead, he turns it back to the player.
Could the GM ask, “What are you willing to pay to get across?” and have the player suggest how things might get complicated for them?