Arknights is a tower defense mobile game developed by Chinese developers Studio Montagne and Hypergryph. The game is set in the dystopian, post-apocalyptic future setting of the planet Terra, where humanesque lifeforms known as Ancients exhibit features of animals or mythological races. Natural disasters leave behind a valuable mineral, Originium, which enables the usage of Arts (the world's form of magic) and often infects people with a progressive disease, Oripathy. Due to the disease's 100% mortality rate, and its high infectivity at the time of death, hostility towards the Infected became widespread, leading to their mass quarantine and expulsion by governments worldwide, and sparking tensions between the Infected and non-Infected. The player takes the role of the masked and amnesiac "Doctor", who had very recently recovered from cryonic sleep. The Doctor commands a team of "operators" contracted to Rhodes Island, a pharmaceutical, medical and self-defense organization. As Oripathy spreads, the team must search for a cure while defending themselves against the Reunion Movement, an Infected anarchist military force bent on overthrowing the governments of Terra in revenge for persecuting Oripathy victims.