Harry Clinton "Clint" Bigglestone III (November 17, 1946 - October 13, 1994) was an avid sci-fi/fantasy fan, technical writer, and well-known member of the gaming, fandom, and S.C.A. communities of the San Francisco Bay Area. As a contemporary, friend, and sometime partner of such early game designers as Dave Hargrave and Steve Perrin, he wrote and published RPG supplements under the company name The Fantasy Factory, including "The Universal Fantasy Supplement," "Overland Encounters," "Underground Encounters," and "Deep Delve."
In 1975, Bigglestone co-founded the longest-running game convention in California, DunDraCon, which still operated as of this writing in 2020.
As a military historian, Bigglestone was a regular consultant to the Oakland Tribune during the Falklands War of 1982. Under the company name Conflict Simulation Systems, he wrote and published "The Killing Ground: Book 1 - Megiddo to Mortgarten," rules for historical miniatures warfare prior to the introduction of gunpowder. He also wrote a Napoleonic chit and board wargame for his son's 10th birthday.
Bigglestone died in 1994 in Daly City, California. He was born in Phoenix, Arizona. His daughter, Branwyn Bigglestone, served as Image Comics' financial controller for several years, and has dabbled in game design as well. His son, Erik Bigglestone, took ownership of the California retail store Games of Berkeley in 2013, and as of this writing in 2020 was serving as the Vice-Chairperson of the Game Manufacturers Association Retail Division Board of Directors.