Dragonborn heritage: Constitution and Defense (5e Feat)
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Dragonborn Heritage: Constitution
Prerequisites: You must be a Dragonborn
As a Dragonborn, your heritage usually has it's root in magic, but it also has it's root in high constitution and a naturally high defense in this case, you have tapped into one part of that more physical heritage.
Tapping into the power that lies waiting inside you, you gain a plus 1 to Con and gain advantage on Con saving throws.
Alternatively, you can tap into the hidden defensive ability you have. Your scales harden and your skin becomes rough, allowing you to gain +1 to your Constitution and add your Constitution modifier to your armor, be it heavy, medium, or light armor.