Title : Book of The Damned
Publisher : Paizo Publishing
First things first, I bought the three original volumes of the Book of the Damned Campaign Settings when they first came out. So going into this I have a slant towards being a fan of this material and lore. I have deep appreciation for the work and effort Paizo puts into crafting their more "forbidden" lore. Unlike a lot of resources about things that are "evil" or that deal with infernal themes, it has been my experience that Paizo finds a more well rounded way of describing and fleshing out various demon lords and hidden cities that exist in the damned realms. Demons and monsters present in these books are not just "Demon Evil, Demon Kill"; they have been thought out, given compelling backstories, and there is enough vague information present on Demon Lords and Infernal beings that a Storyteller can weave into the existing threads of information all sorts of scenarios that will link these beings of dark and terrible power to their already existing campaigns.
Now I understand not everyone feels that this book is as worthy of praise as I do. I am sure if you are a frequenter of the Paizo reviews or backrooms at game shops you might be expecting the normal "I don't understand why I have to pay for reprinted material" gripe. Yes, this book contains a lot of reprinted material from the original three volumes of the Book of the Damned books, however I do not think that detracts from what you are getting with this collected and expanded edition. Those three books were thin softbacks, and while each was amazing in its own right, this massive hardback with a brand new cover and expanded material more than makes up for the cover price in every way. I am a man of meager means, so when I shell out money for a hardback gaming book, I have to be 100% sure I am getting my money's worth and let me tell you, I believe with all certainty that I have.
Furthermore, unlike a lot of campaign settings that I have dug into, Book of the Damned feels as much like a collection of lore and stories that are incredibly entertaining to read as an asset to a Storyteller or DM for all those infernal gaming needs. I have spent a good 5 hours just sitting on my couch, reading the book cover to cover for the pure enjoyment of the story aspects.
The chapter covering the Fiendish Realms is especially noteworthy, as it reads like some kind of infernal trip advisor giving just enough details on all sorts of devilish destinations that it instantly spawned a score of story hooks and campaign encounters to run my players through.
It, however, is a gaming book after all, so aside from the enjoyment you will get from reading about the lore and inner workings of the various levels of the abyss, it has a wealth of information and stats on deities, devils, monsters, magic items, and more. It even delves into a few prestige classes and expands upon some spells and magical abilities.
While I know it is easy for some to disregard a book that has a good amount of reprinted material, if you enjoy the more fiendish and demonic lore in the Pathfinder universe this book is a must have, and a great resource for anyone looking to incorporate devils, demons, and fiends of all kinds into their game.
Ask your local bookstore if they have a copy or you can pick up the Hardcover or grab the PDF from Paizo.com