I think it's interesting that dice rolls in Powered by the Apocalypse actually represent something fundamentally different than they do in D&D and many other systems.
In the classic D&D paradigm a dice result is an effort value. You roll and do a 15 good job of persuading that diplomat, and 15 good may or may not pass the preexisting bar of persuasive enough. The number you roll entirely represents how skillful an attempt you made, and the difficulty represents the state of the world.
[cont]
Implicit in the way Powered by the Apocalypse treats dice outcomes is that the rolled value represents both the quality of the effort made AND the preexisting state of the world.
If you roll a 4 on attempting to persuade that diplomat, the failure might in part be because she was already unable to be persuaded. It also might mean that you were overheard by someone hostile in the adjoining room! The dice result retroactively changes the world's state. It's a waveform collapse.
As a side effect this means you get to entirely stop caring ahead of time about how difficult a challenge might. Just throw the dice, and if you succeed than the challenge was overcomable with you skills and luck, and if not than it wasn't. If a challenge is known to be probably easy to definitely too hard in advance then there's no need to roll.
This is fundamentally hostile to Gamist and especially Simulationist paradigms of play, but is liberational for the Narrativist.