Player's Handbook
You have practiced techniques in melee combat against spellcasters, gaining the following benefits.
- When a creature within 5 feet of you casts a spell, you can use your Reaction to make a melee weapon attack against that creature.
- When you damage a creature that is Concentrating on a spell, that creature has Disadvantage on the saving throw it makes to maintain its Concentration.
- You have Advantage on saving throws against spells cast by creatures within 5 feet of you.