From the introduction: The document includes rules and guidelines as laid out in the 1977 edition of the revised game, Dungeons & Dragons. Since this information was directly transferred and/or interpreted from the original set of rules appearing in 1974-75, what follows is an attempt to clarify those things that are implied within the '77 document, and to provide additional data to support the implications. Nothing that appears within this Primus has been created from any other source/s than the original rules, their implications, and the supplements that followed.