Gamemaster’s Guide Gamemaster’s Guide is a core rulebook for the historical action horror RPG Achtung! Cthulhu, written by Richard August, Brad Bell, Richard L Gale, Benn Graybeaton, Bill Heron, John Houlihan, Mari Tokuda, and Sam Webb and published by Modiphius Entertainment. By Aaron T. Huss Learn more about Gamemaster’s Guide here Purchase Gamemaster’s Guide PDF here (paid...