Jacob Franklin Mentzer III is an American fantasy author and game designer who worked on early materials for the Dungeons & Dragons (D&D) fantasy role-playing game. He was an employee of TSR, Inc. from 1980 to 1986, spending part of that time as creative advisor to the chairman of the board, Gary Gygax. He also founded the Role-Playing Games Association (RPGA) during his time with TSR. After Gygax was ousted from TSR at the end of 1985, Mentzer left TSR as well and helped him to start New Infinities Productions Inc. (NIPI). When this venture failed, Mentzer left the gaming industry, eventually becoming the manager of a bakery. In 2008, he closed down this business and, two years later, returned to the gaming industry as a founding partner of a new publishing company, Eldritch Enterprises. Source: Wikipedia (en)