Chainmail is a medieval miniature wargame created by Gary Gygax and Jeff Perren. Gygax developed the core medieval system of the game by expanding on rules authored by his fellow Lake Geneva Tactical Studies Association (LGTSA) member Perren, a hobby-shop owner with whom he had become friendly. Guidon Games released the first edition of Chainmail in 1971 as its first miniature wargame and one of its three debut products. Chainmail was the first game designed by Gygax that was available for sale as a professional product. It included a heavily Tolkien-influenced "Fantasy Supplement", which made Chainmail the first commercially available set of rules for fantasy wargaming, though it follows many hobbyist efforts from the previous decade. Dungeons & Dragons began as a Chainmail variant, and Chainmail pioneered many concepts later used in Dungeons & Dragons, including armor class and levels, as well as various spells, monsters and magical powers.