Shield

1st Level Abjuration

Casting Time: 1 reaction, which you take when you are hit by an attack or targeted by the magic missile spell
Range: Self
Components: V S
Duration: 1 round
Classes: Sorcerer, Wizard

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.