Ninja Gaiden, also known as Ninja Gaiden: Worlds of Power #3 or Worlds of Power: Ninja Gaiden, is a novelization of Ninja Gaiden for the Nintendo Entertainment System published in 1990 by Scholastic. It was written by Peter Lerangis under the pen name "A.L. Singer" but published under the name "F.X. Nine" as all other Worlds of Power books.
It is the third in the Worlds of Power series, novels based on Nintendo games made to capitalize on the systems popularity, featuring game hints and tips of dubious quality. Like other books in the series, the books was published under the author name of 'F.X. Nine' in order to have the book appear after "Nintendo" under the author name. The novelization features many changes to the story including changing both Ryu Hayabusa and Irene Lew's ages to 13 and adding some original characters such as Ryu's mother and Akira, Ryu's Ninja instructor.
Like other Worlds of Power books, violence against humans was minimized and character deaths were removed, including that of Jô Hayabusa, known as Ken in the book.