The most common form taken by Atun's Ring is either a single band marked with one rune associated with each of the six realms or a single ring formed of six interwoven bands, each of a different precious metal.

These rings are named for the paragon Atun, the sister of Atuman, exemplar of Ambition. Stories indicate that Atun was a powerful magician, prone to visionary experiences even without the use of magic, and a mistress of multiple realms. When she departed the nascent Highborn nation she left the artefact magical ring that bore her name with her brother as a keepsake. Her followers crafted lesser rings in its image, and when the Freeborn began their exodus it is believed that all three founding sisters bore versions. The use of the rings was also widespread among the magicians of Tassato and Sarvos, and three were given as gifts by Highborn magisters to the magicians of Urizen during early diplomatic exchanges. Of these three rings, one resurfaced during the Summer Solstice 385YE in possession of the Hall of the Newborn Sun in Morrow. It was presented to the Imperial Conclave by the Urizen spire, to be endowed on the person most responsible for the destruction of Druj miasma pillars in Zenith. The Bursar of the Conclave had the ring endowed on Caleb of the Cenotaph, exarch of the chapter of the same name and a renowned master of the Chimes of Annulment ritual. The whereabouts of the other two rings are currently unknown.

The original ring would be a treasure beyond price, were it to be found, but it vanished during the tumultuous years of the Highborn civil war. Its last known bearer is believed to have been Permion the Lawmaker, and it was not seen again after his assassination.