Every roll at this table tells you two things at once: did it work, and what did it cost you. There's no modifier math, no "+3 to hit," none of that. You just build a pool of dice and it tells you exactly how your life is about to go.
Your Ability and Proficiency dice are you making your case. The GM's Difficulty and Challenge dice are the universe saying "we'll see about that." Nothing cancels out clean either, success and failure duke it out, advantage and threat duke it out, and whatever's still standing when the dust settles is what actually happens. It's less "did I hit" and more "how bad was it."
Set how many of each die the GM tells you to grab, hit the button, and let chaos decide. Success cancels Failure one for one, Advantage cancels Threat one for one, and whatever survives that fight is exactly what happens to your character. No takebacks.