I'll start by saying the book is a good book for anyone playing in the Forgotten Realms setting. This book is perfect for DMs and not as important for players, although players who wish to play in an evil group will find this book very useful. Any DM that wishes to tackle the pcs with an evil group will find a lot of support and ideas in this book including stats, items, influence, npcs, allies, locations, maps etc. It also adds a handful of prestige classes specific to some of the evil groups including Church of Cyric (Spur Lords), Worshipers of Entropy(Entropist), Zhentarim's Sky mages, Thayan Knights of the Red Wizards and even the Darkmask for surface drow that follow Vhaeraun. The end of the book contains favored magical items and favored spells to some of the groups. Some of the groups have character leaders stats and items. I had to hold back from rating this book as a single reason which I thought is important as someone who plays with psionics. The books contains no psionical support, or even a psionical option, for cults like the Mindflayers which are obviously psionically oriented. Other than that, I highly recommend the book, especially for playing in or against evil groups.