Lucky Feat / Trait with advantage / disadvantage
There are different Lucky Feats and traits.
The Halfling Lucky trait:
"When you roll a 1 on the d20 for an attack roll, ability check, or saving throw, you can reroll the die and must use the new roll."For rules clarification, your re-roll only replaces the 1, not both dice (unless both were ones on the first roll.) This is clearly laid out in the Rules for advantage and disadvantage
"When you have advantage or disadvantage and something in the game, such as the halfling's Lucky trait, lets you reroll or replace the d20, you can reroll or replace only one of the dice. You choose which one. For example, if a halfling has advantage or disadvantage on an ability check and rolls a 1 and a 13, the halfling could use the Lucky trait to reroll the 1."
Luck Feat
RAW effectively turns disadvantage into supper advantage, and that does not seem to be the Rules as Intended. Sage Advice does explain this as Rules as Written but it also provides an alternate ruling for dealing with Lucky feat with advantage / disadvantage that we will be using."Roll two d20s for advantage/disadvantage, roll a third d20 for Lucky, eliminate one of the three dice, and then use the higher (for advantage) or lower (for disadvantage) of the two dice that remain."This is consistent with the above clarification on how Advantage / disadvantage work in that:
"you can reroll or replace only one of the dice."
