Shin Megami Tensei is a popular role-playing video game series developed by Atlus. The games typically feature a post-apocalyptic setting where players assume the role of a protagonist who can summon and negotiate with various demons. Players explore dungeons, engage in turn-based combat, and make choices that affect the game's story and ending. The series is known for its complex themes, including morality, religion, and the nature of humanity. Each installment often introduces new gameplay mechanics and storylines, while maintaining the core elements of demon collection and fusion, allowing players to create powerful allies for battles.