A professional television screenwriter whose credits ranged from Babylon 5 and The Hitchhiker to He-Man and the Masters of the Universe and Conan the Adventurer, DiTillio began writing for roleplaying games in 1983 when he was out of work due to a strike. Co-creating Masks of Nyarlathotep with Lynn Willis, he came up with its conception and plot, and he wrote the first draft of Chapters One through Six. In addition, he wrote scenarios for Chaosium's Pendragon and Stormbringer RPGs.
Comments / Trivia
• DiTillio created his own percentile-based fantasy RPG system, Cerilon
• The WGA West awarded DiTillio its Morgan Cox Award "in recognition of his longtime service to the Guild and his dedication to helping empower and improve the working conditions of his fellow writers".