From the web site: Altars and Archetypes is designed to be ultra fast and simple. It is fairly free-form and should allow a great deal of flexibility. It was written with the sword and sorcery genre in mind but you should be able to use it for any genre with the possible omission/addition of a rule or two here or there. The core mechanic of the game is essentially skill die vs difficulty die, although rather than skills per se characters are described by archetypes which each represent a broad range of skills and qualities.