(This review originally appeared in slightly different form at RPG Geek.)
This book is the second of four "core" books released by Chaosium in the early 2000s, the others being The 1920s Investigator's Companion (1997), The Creature Companion (1998), and The Keeper's Companion vol. 2 (2002). Like the other three, this is not "core" in any meaningful sense of the word, and is certainly not a requirement to play the game -- all you need for that is the basic Call of Cthulhu
book.
About a quarter of the book is taken, with slight modifications, updates, and corrections, from the original Keeper's Compendium (1996). The majority of the book was written by Keith Herber, with a list of supplemental authors that read like a who's-who list of Cthuloid luminaries (including Aniolowski, Petersen, and Ross).
This book does not has a unifying theme (other than "for Keepers") but is an anthology of material covering a diverse array of subjects. As such, the chapters skip around a fair amount, and also their utility will vary wildly from Keeper to Keeper. This is to be expected. Anthologies in general are not all things to all people and, in my experience, tend to be very hit and miss.
