Similar to the Fate Fudge dice, sometimes a DM might "Fudge" a dice roll (without using the actual Fudge dice). I.e., they might make a roll pass/fail, regardless of what is on the actual dice.
For example, if a PC is low on health, and the DM rolls a critical hit on that PC they might "Fudge" it to lower it from a critical hit so the player might not die outright.
In what situations should a GM "Fudge" a dice roll, and how should it be handled?