His novel Starhammer has been cited by computer programmer Jason Jones as an important literary influence in the creation of the Halo video game series by Bungie.
[citation needed] In the 1990s, Rowley switched to the fantasy genre with the success of his first novel for Roc Books, Bazil Broketail.
This novel was set on the imaginary world Ryetelth and involved the adventures of battledragons and the boys that care for them in the service of the legions of the nine cities of the Argonath.
In the 1980s and 1990s he also co-wrote two television animated series by Robert Mandell, The Adventures of the Galaxy Rangers and Princess Gwenevere and the Jewel Riders.
In February 2009, Rowley's first illustrated novel, titled Arkham Woods, a supernatural tale of horror inspired by the Cthulhu Mythos of H.P.