@Hard_ViceWill Mage Armor work with Unarmored Defense? I’m guessing since each specifies an AC formula, MA would replace UD. "Will Mage Armor work with Unarmored Defense? I’m guessing since each specifies an AC formula, MA would replace UD."

Correct.

— Jeremy Crawford (@JeremyECrawford) January 21, 2015

@BrailSays "RAW,would a monk/druid retain Unarmored Movement while shifted?"

Yes.

— Jeremy Crawford (@JeremyECrawford) January 21, 2015