This and other magic items I've created are collected together in the attached PDF.
House Adhorren Ring: A signature ring of House Adhorren, one of the five magister houses of the Queen's Wood. +2 to any type of arcane knowledge check, and once a day add 2d4 force damage to a damage roll for any attack after you see whether or not the attack hits.
Quirk: Secretive. The one wearing this ring will often find themselves being overly secretive about mundane events and aspects of their life, typically for no good reason.