A translucent barrier of magical force appears in the shape of a shield and protects you and your allies.

Until the start of your next turn, including against the triggering attack, whenever you or an ally within 10 feet is required to take a save (such as a Dexterity save), you take no damage on a successful save and only half damage on a failed one. 

If you cast this as a 4th level spell, it becomes a Concentration spell with a duration of 1 minute.