Disgaea 4: A Promise Unforgotten is a tactical RPG and the fourth installment of the Disgaea series by Nippon Ichi Software. Using turned based combat and the isometric battlefield gameplay from the previous installments, Disgaea 4 includes new features, such as the Magichange system.

Disgaea: Hour of Darkness is a tactical role-playing video game developed by Nippon Ichi Software for the PlayStation 2, Playstation Portable (as Disgaea: Afternoon of Darkness), and Nintendo DS (Disgaea DS).