Devil Survivor 2 is set in Japan, where the protagonist and his friends join a website called Nicaea (ナイシェア Naishēa), which sends them a strange message telling them to witness the "end of the world." They soon find out that they have been given the power of summoning demons from cyberspace in order to fight mysterious creatures invading the cities. With their newly acquired powers, they must survive seven days of turmoil while facing both human enemies and monsters.
The game follows a turn-based strategy RPG format, with players taking control of characters as they battle through randomly generated dungeons filled with monsters. During battles, players can summon demons to aid them in combat. Players also have access to an array of skills and abilities that can be used to gain an advantage over their foes. The story progresses through multiple branching paths depending on player choices throughout the game.