Fundamentals of Tabletop Roleplaying is a basic guide to what tabletop roleplaying games are, and how one goes about playing or organising such a game.
Situations For Tabletop Roleplaying (and the follow-up second set) give a simple series of fill-in-the-blanks forms for tabletop Guide to build situations for play.
Schema is a simple rules engine for resolving tabletop action - one in which complex stakes are handled, and bold or cautious action is especially meaningful.
Witchcraft For Schema gives a system of magic and a set of basic traditions for witches, all of which are arranged to integrate with the world presented here smoothly and easily.