Be it the darkest depths of the demon-haunted Abyss, the apocalyptic realm of Abaddon, or the infernal layers of Hell itself, the denizens of these evil planes of existence have long tempted, tormented, and tortured mortal life. From the lowliest imp to the mightiest demon lord, these realms are ripe with horrors and festering with threats to body, mind, and soul. And the route to knowing these blasphemous secrets are held within the infamous pages of the Book of the Damned. Pathfinder RPG Book of the Damned explores the workings of these powerful forces of evil, focusing on the numerous demigods that influence mortal life and the countless fiends who prey upon the living and dead alike. Within these pages, you'll find details on demon lords and arch devils, information on the realms of Hell, Abaddon, and the Abyss, and rules for incorporating fiendish influences into your game--be they in the form of foes for heroic parties to face, or temptations for less scrupulous adventurers to consider. Pathfinder RPG Adventurer's Guide includes: * Information on the sinister boons granted worshipers of dozens of fiendish demigods drawn from the planes of Abaddon, the Abyss, and Hell, including Archdevils, Demon Lords, and the Four Horsemen of the Apocalypse. * An exploration of the infernal realms of Hell, the sinister reaches of Abaddon, and the bottomless rifts of the Abyss. * New feats, spells, magic items, and prestige classes for use by characters who both fight against and serve the forces of darkness. * Rules for infernal contracts and sinister rituals. * Statistics for several never-before revealed fiends and lavishly-illustrated in-world excerpts from the pages of the notorious Book of the Damned itself. * ... and much, much more!