It was announced that Reki Kawahara’s Sword Art Online light novel series is beginning a new arc called Sword Art Online: Unital Ring. Dengeki Bunko’s 59th issue published the prologue chapter to the new arc. Reki Kawahara stated that the name uses a mathematical term much akin to the Ordinal Scale name. Despite the fact that the two arcs use a mathematical term, Kawahara-san stated that there are no plans to link the two arcs together.
While no major details were revealed about the plot, Kawahara-san stated that throughout the series, the games have evolved. For instance, Sword Art Online was about pure fantasy. ALfheim Online took that fantasy and gave players the power of flight. Gun Gale Online was more about a gritty world with guns and other weapons. Here in Unital Ring, the characters will be starting over from scratch with no strategy guides or “Wikipedia” to aid them in their quest. There was no mention what setting this new VRMMO game will be other than everyone starts from zero.
The Sword Art Online franchise recently received a green light for a third anime season which will cover the Alicization arc as well as an anime season dedicated to a spinoff novel series from the Gun Gale Online arc. Those seasons will air next year in 2018. Since the light novels are just beginning to publish, it is obvious that there is no anime adaptation announcement for Unital Ring.