You play as a newly appointed Captain of the Guardians. Your story begins with a desperate defense of a frontline outpost. As you progress through the game:
: Massive story events where players work together to take down "World Bosses" that threaten the entire subterranean civilization.
: The "OL" (Online) aspect reflects the story's focus on unity; you must recruit heroes from different subterranean factions—such as Dwarven engineers, Elven druids of the fungal forests, and human mages—to form an unstoppable team.
: You lead expeditions into lost tunnels and forgotten ruins to clear out the Void corruption.