The Rings project an electromagnetic field which deflect magnetic projectiles and as energy-based weapons discharges. The Rings do not grant the wearer complete immunity, however and were sometimes used, by the Isu, in conjunction with a shielding device.
In the decades preceding the Great Catastrophe, the Isu attempted to adapt the principles behind the Rings to create a shield that could protect the whole planet from the impending cataclysm. However, they didn't have the time or resources to make even a large enough shield to safeguard a single city, and so they abandoned the research for other, more favorable solutions.
During the late 17th century, a Ring came into the possession of the renowned privateer-turned-pirate William Kidd, and its ability to deflect metal or, more specifically, lead musket balls, contributed to folklore stories of his invincibility. Kidd eventually chose to hide his Ring on Oak Island, to keep it safe from Templar forces who sought it. To this end, Kidd created a map that provided clues to the Ring's location, and divided it among four of his former crew members before he was captured by the British and executed.
Years later, the Assassin Connor managed to gather the four pieces of the map from "Peg Leg", who sat near the docks of his ship, and, along with Robert Faulkner, traveled to Oak Island to obtain the Ring. Though both wondered why Kidd protected this "treasure" so carefully, Connor soon realized its power when it threw Faulkner's whiskey flask out of his hand.
- In Assassin's Creed III, the artifact is referred to as a "Shard of Eden".
- Subsequent to Connor's acquisition of the Ring, its effects were present while reliving the memories of Haytham Kenway.
- The Ring's effect could also be observed on Desmond Miles after he had relived the memory in which Connor found it.
- The Ring shares many features with the rings of Neodymium magnets that are found in miniature motors, which give off a strong magnetic field.