Watson was often asked to come up with the stories and adventures for these games during lunch, building his ability to improvise and connect narratives.
[12] Watson said, "My father brought home this red box labeled ‘Dungeons & Dragons.’ He told me that ‘it looked interesting,’ and that I should ‘really learn how to play it.’ So I did.
[12] Watson wrote for several D20 projects, including the Penumbra Fantasy Bestiary, Sorcery & Steam, and the award-winning Dawnforge: Crucible of Legend.
He joined the company as the Lead Developer for Dark Heresy, became the principal architect of Rogue Trader and Deathwatch, and helped design Black Crusade.
Accursed is a campaign setting that "combines Hellboy with Solomon Kane," where the players take on the roles of classic monsters fighting against evil witches who have conquered their land.
[14] Watson became the company's managing director and has overseen the production of books for Shaintar, a high-fantasy setting for the Savage Worlds RPG.
[4][3] Evil Beagle also collaborated with High Rock publishing, again with Watson as lead developer, to create a new edition of Aaron Allston's Strike Force in 2016.
[17] Watson contributed to the No Quarter Presents: Urban Adventure project for Privateer Press and In Defense of Innocence[18] for Wyrd Games.
[8] On Darksiders II,[7] Watson worked on portions of the main game's script and wrote the stories and dialogue for all three DLCs.