Armored Shell

This spell creates a suit of magical studded leather armor (AC 12). It does not grant you proficiency in its use. Casters without the appropriate armor proficiency suffer disadvantage on any ability check, saving throw, or attack roll that involves Strength or Dexterity and cannot cast spells.

At Higher Levels: Casting armored shell using a higher-level spell slot creates stronger armor: a chain shirt (AC 13) at level 2, scale mail (AC 14) at level 3, chain mail (AC 16) at level 4, and plate armor (AC 18) at level 5.

-- From Kobold Press