Reading all these magic items for the OSR Superstar contest got my juices going. The urge to create my own magic items was beset upon me. I'm not sure if I'm using beset correctly, but I'm feeling beset. Anyway, this magic item comes from the game I ran the other week. It's a variation of an oldie but a goodie.
Ring of Holding
These rings were often used to transport important documents in the old kingdoms, but as the rings aged they became more unreliable. At times, what was placed within could not be retrieved, as if it were stuck. Or if the person wearing the ring was jarred or fell, whatever was hiding within would pop or peek out of the ring.