There are 3 books in The Three Worlds Trilogy series.
The Three Worlds Trilogy series does not have a new book coming out soon. The latest book, The Reign of the Brown Magician (Book 3), was published in May 1996.
The first book in The Three Worlds Trilogy series, Out of This World, was published in October 1994.
The Three Worlds Trilogy series primarily falls into the Fantasy genre.