Elemental master

When you gain this feat, choose one of the following damage types: acid, cold, fire, lightning, or thunder. Your chosen damage type must be one which you have already selected with the Elemental Adept feat. Spells you cast ignore resistance and immunity to the chosen type, and whenever you roll damage for a spell that deals damage of the chosen type, you may reroll any 1s or 2s until the resulting rolls yield a result of 3 or more.