Elemental Master (5e Feat)
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Prerequisites: The Elemental Adept Feat
When you gain this feat, choose one of the following damage types that you have already taken for the Elemental Adept Feat: acid, cold, fire, lightning, or thunder. When you cast a spell the deals your chosen damage type, you ignore resistance to that damage type and treat immunity as resistance and absorption is treated as immunity. You can select this feat multiple times. Each time you do so, you must choose a different damage type.