Shield

1st-level (abjuration; arcane, protection)
Class(es): Sorcerer, wizard
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

You create a shimmering arcane barrier between yourself and an oncoming attack. Until the spell ends, you gain a +5 bonus to your AC (including against the triggering attack) and any magic missile targeting you is harmlessly deflected.