Medium Armor Master
Prerequisites 4th, Proficiency with medium armor
You gain the following benefits.
Ability Score Increase. Increase your Strength or Dexterity by 1, to a maximum of 20.
Dexterous Wearer. While you’re wearing Medium armor, you can add 3, rather than 2 to your AC if you have a Dexterity score of 16 or higher.
Sources
Player’s Handbook (2024) p. 205