Mark Schumann worked for R. Talsorian Games, where he designed books for Castle Falkenstein, Cyberpunk 2020, and Mekton Zeta. He was line manager, chief editor, and writer for the Castle Falkenstein and Mekton Zeta product lines, and contributor on several Cyberpunk 2020 supplements. He has also done work for Chaosium, Pagan Publishing, Wargaming Group Limited, VIZ LLC, Sephora, Safeway, Cost Plus World Marketplace, The Gap, Hardy Marks Publications, Lombardy Studios, and the World War One Historical Association.