War Caster

General Feat (Prerequisites: Level 4+, Spellcasting or Pact Magic Feature)

Ability Score Increase. Increase your Intelligence, Wisdom, or Charisma score by 1, to a maximum of 20.

You gain the following benefits.

Concentration.

You have Advantage on Constitution saving throws that you make to maintain Concentration.

Reactive Spell.

When a creature provokes an Opportunity Attack from you by leaving your reach, you can take a Reaction to cast a spell at the creature rather than making an Opportunity Attack. The spell must have a casting time of one action and must target only that creature.

Somatic Components.

You can perform the Somatic components of spells even when you have weapons or a Shield in one or both hands.

Source: PHB'24, page 209