Why do I like this book? ...because it manages to be d20 without overemphasizing the rules. Oh, they're there if you want 'em, listing feats that might apply to each template variant, etc, but the emphasis is on the story behind the crunch--the nature of the powers derived from the templates, various inherent flaws, etc. A word of warning to some, these templates are not four-color, or silver age. These are gritty, iron age, Frank Milleresque. ...not exhaustive, but well thought-out.