Gygax authored numerous fantasy novels, often set in or inspired by the Greyhawk world. These novels expanded on the lore and characters he created for D&D. Notable examples include the Gord the Rogue series.

Gygax was a frequent contributor to Dragon magazine, writing articles on various aspects of D&D, game design, and the Greyhawk setting. These articles provided valuable insights for players and Dungeon Masters.

While best known for D&D, Gygax worked on other role-playing game systems, including Dangerous Journeys and various historical wargames, demonstrating his broad expertise in game design.