You add your Constitution modifier to your Armour Class in addition to your Dexterity modifier when not wearing armour.
Description
Your body is as resilient as any armour. While not wearing armour, you add your Constitution Modifier to your 
Armour Class. Wearing Heavy Armour impedes your Rage.
Progression
- Learns at level 1: Barbarian
Notes
- This ability does not stack with Mage Armour or Unarmoured Defence (Monk).
- Unarmoured Defence can work with Wild Shape, but the character must have no medium or heavy armour equipped in any item slot prior to transforming.