what game is castlevania nocturne based on

Castlevania: Nocturne is a stand-alone sequel to the animated series Castlevania, and it is based on the video game series of the same name by Konami and loosely adapted from Castlevania: Rondo of Blood and Castlevania: Symphony of the Night. The series is set in 1792 during the French Revolution and follows Richter Belmont, a descendant of the Belmont family, his adoptive sister Maria Renard, and the dhampir Alucard. While Castlevania: Nocturne is based on the video game series, it is not a direct adaptation of any particular game in the series.