Arknights is a Chinese mobile tower defense gacha video game developed by Studio Montagne, Hypergryph. It was first released in China on 1 May 2019. Its global server was then released on 16 January 2020 by Yostar. The game is available on iOS and Android platforms.

The game is set in the dystopian, post-apocalyptic future setting of the planet Terra, where magic exists and the humans of Terra exhibit features of animals or mythological races. Natural disasters leave behind a mineral, originium, which infect 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.

The player takes the role of the masked and amnesiac "Doctor", recently recovered from cryonic sleep. The Doctor commands a team of "operators" belonging to Rhodes Island Pharmaceuticals, a 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.