A barrier of arcane force approximately the size of a shield appears and protects you. This can appear in front of you or on your arm for the duration of the spell. Until the start of your next turn, you have a +1 bonus to AC, including against the triggering attack. This cantrips bonus to AC increases by +1 when you reach 5th level (+2), 11th level (+3), and 17th level (+4).
This cantrip will completely block a single missile from the magic missile per +1 of AC granted each round when activated. Example: When the caster is targeted by a 1st level magic missile spell they may block one of the three missiles at level 1, two missiles at level 5, and all 3 missiles would be blocked at level 11.
* - which you take when you are hit by an attack or targeted by the magic missile spell.