Hat of Wizardry

(Requires attunement by a Wizard)
While you wear this hat, you can use it as
spellcasting focus for your wizard spells.
You can cast a cantrip that you don't know from
the Wizard spell list, you must make a DC 10
Arcana check. On success, you cast the spell.
On fail, so does the spell, and the action used
to cast the spell is wasted. Once per long rest.