Elemental Adept: Fire is a Passive Feature obtainable by the Elemental Adept Feat. Your spells ignore Resistance to 
Fire. When you cast spells of that type, you cannot roll a 1.
Description
Spells you cast ignore Resistance to Fire damage. In addition, when you deal Fire damage with a spell, you cannot roll a 1.
How to learn
Granted by feats: Elemental Adept