Mage Armor

D&D 2014 spell: Mage Armor. Source: Player's Handbook (2014). level 1, school Abjuration, casting time 1 action, range Touch, duration 8 hours

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.

Source: Player's Handbook (2014), p. 256 - Licenses and attribution