question about fighters defense fighting, can i get that +1 ac when wearing leather armor, and then use mage armor? (13+dex+1)Murky under rules, but I'd allow it. Mage armor might not count as armor, but it probably should.
— Mike Mearls (@mikemearls) July 23, 2017
You sometimes wish that Mearls would read his own companies’ information. Mage Armor “You touch a willing creature who isn’t wearing armor, and a protective magical force surrounds it until the spell ends. The target’s base AC becomes 13 + its Dexterity modifier. The spell ends if the target dons armor or if you dismiss the spell as an action.”
Spell doesn’t work if you are wearing armor, stops if you don it. Not TERRIBLY murky.