Michael has published over 70 novels in all genres. These include several series that share a common multiverse: The Cornelius Chronicles, The Dancers at the End of Time, Erekose, The Books of Corum, Hawkmoon: The Chronicles of Castle Brass, Hawkmoon: The History of the Runestaff and the classic Elric of Melnibone Saga. He has also edited an anthology of late Victorian science fiction, Before Armageddon. Under the pen name E.P. Bradbury, he published a series of novel-length pastiches of Edgar Rice Burroughs' Barsoom novels.