Stone has written many spin off novels based on the BBC science fiction television series Doctor Who and Judge Dredd.
Stone also contributed a number of comic series to 2000AD and the Judge Dredd Megazine, focusing on the Dreddverse (Judge Dredd universe). In collaboration with David Bishop and artist Shaky Kane he produced the much disliked Soul Sisters. Working independently, he created the better received Armitage, a Dreddworld take on Inspector Morse set in a future London, and also contributed to the ongoing Judge Hershey series.
Stone’s most lasting contribution to the world of Judge Dredd might well have been his vision of Brit-Cit, which until Stone’s various novels had been a remarkably underexplored area.