Honkai Impact 3rd is set in an alternate version of Earth, plagued by catastrophes resulting from the Honkai. The Honkai is largely viewed as a malevolent force with a will of its own. It has the ability to corrupt humans (ranging from mind manipulation and diseases to turning them into undead creatures), create various monsters, and imbue certain individuals with god-like powers, enabling them to trigger apocalyptic events. These super-powered humans are known as Herrschers. The Honkai is a cyclical phenomenon, returning to test civilization on Earth each time it gets too advanced.
The game takes place in the year 2015 of the Current Era, with the more technologically-advanced Previous Era having been destroyed by Honkai 50,000 years prior. In the Current Era, various global factions exist to combat or take advantage of the power of Honkai. These include Schicksal, a European-based peacekeeping organization that deploys human warriors known as Valkyries to combat the Honkai; Anti-Entropy, formerly the North American branch of Schicksal that objected to the use of human soldiers in favor of mechanized robots; and World Serpent, a shadow organization that has been manipulating world events since the end of the Previous Era.
Three Herrscher awakenings (or Impacts) have already occurred in the Current Era by the start of the series: the Herrscher of Reason, who became the leader of Anti-Entropy instead of fighting humanity; the Herrscher of the Void, who was defeated by Schicksal and Anti-Entropy in 2000; and the Herrscher of Thunder, who was successfully prevented from fully awakening and sent to train as a Valkyrie at Schicksal's St. Freya Academy.
Honkai Impact 3rd is part of a fictional multiverse, with several of its characters being alternate versions of themselves who appear in other miHoYo titles, such as Houkai Gakuen 2, Genshin Impact, and Honkai: Star Rail.
