Clark Peterson is the founder of Necromancer Games.

Clark Peterson and his old friend Bill Webb formed Necromancer Games in the spring of 2000 to publish role-playing materials using the impending d20 license; on August 10, 2000, the same day Wizards of the Coast was to release the new Player's Handbook at GenCon 33, Peterson and Webb published a free PDF adventure called The Wizard's Amulet just a few minutes after midnight that same day.^{[1]: 246–365} On September 13, 2000, Necromancer Games announced a partnership with White Wolf in forming their "Sword & Sorcery" imprint, and Peterson and Webb produced many of White Wolf's rulebooks including Creature Collection (2000), Relics & Rituals (2000), The Divine and The Defeated (2001), and Creature Collection II (2001).^[1]: 365 Peterson ran "Return to the Caverns of Thracia" as a tournament at GenCon XXXV in 2002, after Necromancer Games formed a partnership with Judges Guild to release Judges Guild products.^[1]: 70

Peterson was initially a big supporter of the GSL for fourth edition D&D when it was announced on April 2008, but by July after seeing the reality of the new license he declared it "a total unmitigated failure".^[1]: 296