Veteran Warrior (5e Feat)
From D&D Wiki
Prerequisites: Strength or Dexterity 20, Extra Attack Feature
As a veteran of many battles you have learned where to attack, and how to take advantage of any situation. You now have double your critical chance: 20 becomes 19-20, 19-20 becomes 17-20. When you take the attack action you can attack two additional times, this replaces the extra attack feature.