The magus ring is one of four ancient rings which currently boasts the highest magic attack bonus of any ring, surpassing the imbued seers ring by +3. This ring also provides a magic damage bonus of 2%. Its predecessors, the imbued and regular seers ring are the only other rings to provide magic damage bonus at 0.5% and 0.2%, respectively. The ring requires players to have killed Duke Sucellus at least once to wear, which is done during Desert Treasure II - The Fallen Empire; attempting to wear it otherwise will result in the message The ring slips off your finger. The power within it seems unfamiliar.

The ring requires level 90 Magic and 80 Crafting to create (both being boostable), as well as having learnt how to combine Fremennik ring icons with ancient vestiges via Peer the Seer.

Players who are able to craft the ring must first combine the seers icon and the magus vestige, obtained as an untradeable drop from Duke Sucellus. Next, they must bring the resulting magus icon to a furnace, alongside three chromium ingots and a ring mould, to craft the ring.

Unlike their predecessors, the Fremennik rings, the ancient rings cannot be imbued.