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.