Well, I have the MAG handy so let's pull that out.
EDIT: Actually, if I recall correctly, one of the ways to use nudges is to add dice to your next roll. Some hope.
Outis is correct about using Nudges on failures.
Nudges have only one effect when your roll fails: each reduces the number of Complications that are introduced, before they’re chosen. Nudging Complications below 0 has no effect (as once you’re down to no Complications, you’ve done all you can to mitigate your character’s failure without reversing it, and that’s beyond even fate’s control).
So adding dice to future rolls is only a function of Nudges on successful actions.
So just to clarify, rolling not a single matched pair isn't "a Result of 0" which sounds like it could tie, and therefore possibly break a tie with Nudges, against a defense of 0. A roll with not a single matched pair is simply "automatic failure, regardless of what the other guy rolls", yes?
The Result of a roll with no matching set from 1 to 5 is considered 0 (a failure).
So the Result is
considered 0, which is important for calculating Complications, but is still considered a failure.
Narrators can and should use Difficulty as a way of making tasks both more challenging and more dramatic — because what fun is a challenge, and how valuable is the reward, if there’s no risk of failure? That said, without a compelling reason, the Narrator should usually default to a Difficulty of 1 (Simple)
The Contest succeeds if the attacker scores a higher Result than the target and beats the Difficulty (if any). Nudges break ties as usual, and tied Nudges mean the struggle continues into the next Conflict Round.
Unless something changes it (like the Narrator), just consider attacks, like all other rolls, to have a default Difficulty of 1. Since the contested roll only succeeds if the Result is higher than the target and
beats the Difficulty, a Result of 0 is still a failure no matter how poorly your opponent rolls or how many Nudges you may have.