From the Introduction:
Against the Dead is a role-playing game in the tradition of your favorite zombie movie. Set in a world much like our own, the game pits your character against the unrelenting hordes of ravenous corpses that grow legion as each hour passes. Only the strongest, bravest, and most resourceful individuals have a chance of surviving this threat. Rarer still are those who can take advantage of the rise of the dead and not simply survive, but emerge as a master of the new world in the wake of its cleansing at the hands of the undead.
Against the Dead is a fast paced, action oriented game that can be played either as a one or two session break from other games, or as an epic campaign that follows the fate of the world from the earliest reports of zombies rising to the last days of an apocalypse where the continued existence of life on Earth is in question. To facilitate these different approaches, the game presents the world in three stages of the zombie threat. First is the Emergence Stage, where zombies are few and mysterious. Next is the Ascendance Stage, in which zombies are quickly becoming as common as living folk and all the devices of civilization are being arrayed against them. Finally there is the Apocalypse Stage, where zombies are the norm and humans are scattered and few, faced with the real possibility of extinction.
The world of Against the Dead is described only as it relates to zombies. In all other ways it is the world that you woke up to this morning. Until people started to actually see the dead walk, zombies only existed in movies and comic books. Magic was fictional. Radiation could not infuse recently dead corpses with power. Faith was a personal matter that hadn't manifested a true miracle since ancient times. But something happened...
Against the Dead is not concerned with why the dead have begun to walk the Earth. They simply have. Some zombies are created by infectious disease, spread as the undead are driven to consume human flesh. Others are the result of profane magical or dark religious rites. Still others are created by radiation. Individual Game Masters are welcome to create whatever explanation they like for the rise of the dead. Or perhaps there are many explanations. Regardless, your character must find ways to fight the zombies or join their pile of partially consumed victims... perhaps to rise as one shortly thereafter.
Based on the d20 Modern System Reference Document, Against the Dead presents a streamlined version of the rules that deals exclusively with zombies and ways to fight them. The only material you need to play the game is this book, a set of gaming dice, and a pencil and paper. Miniatures to represent characters and zombies are recommended, but not necessary. A CD or two of panicky ambient music can greatly assist the atmosphere of a game session, as can a soundtrack from any of the hundreds of zombie movies - good and bad - that have been produced over the years.
Presented in a straightforward "crunchy" style that should appeal to experienced gamers and newbies alike, Against the Dead doesn't spend a lot of time with detailed descriptions or dense prose. We've all seen the flicks. We know what a good old fashioned zombie infestation looks like. The dead are out there. Go get 'em.