Perrin earned a Bachelor of Arts in English from San Francisco State University.

[3]: 83 One of his first contributions to the world of RPGs was "The Perrin Conventions" in 1976, an alternative set of combat rules for Dungeons & Dragons, which led to his work on RuneQuest.

[3]: 83 [4] Perrin wanted more involvement in the role-playing game industry, and with Jeff Pimper he talked to Chaosium about developing a creature book based on Dungeons & Dragons, which they published as All the Worlds' Monsters (1977), and was released before the Monster Manual from TSR.

[3]: 83  Perrin later worked with Steve Henderson and Warren James on an idea for an original gaming system to be used with the world of Glorantha after a previous design team failed to produce a supplement to an existing game, and Ray Turney from the original team soon joined them; this new RPG was finally published in 1978 as RuneQuest.

[3]: 85  Perrin designed Worlds of Wonder (1982), which was the third game released by Chaosium using their Basic Role-Playing system (BRP).