There is plenty of theory and before you get into the meat of the book, exactly what is and what isn't a CRPG is discussed in great detail. For the most part I agree with the definitions and delineations of the various related genres (adventure, RPG, MUDs, JRPGs, etc.) and I believe this can be used as the basis for future works by other authors. In short, the reader gets a clear picture of what exactly the author means by "CRPG" in its many forms and why some of the other games - even though they might exhibit several RPG characteristics - really fall under another classification.