Call of Cthulhu has no magic items in the D&D sense — it has objects that cost you something to own. These are tomes, relics and cursed things: what studying one does to an investigator's Sanity, what it teaches, and how many weeks it takes to get through. Each is written to be handed across the table as a prop and regretted a session later, its Mythos knowledge priced in Sanity rather than gold.