Basic Rules , pg. 275
Shield
1-level
Abjuration
Casting Time 1 Reaction
Range Self
Duration 1 Round
Components V, S
Damage Type: Protection/None
Saving Throws: None
Description: An invisible barrier of magical force appears and protects you. Until the start of your next turn, you have a +5 bonus to AC, including against the triggering attack, and you take no damage from magic missile.
Class(es): Sorcerer, Wizard