From the back of the book:
THE EMPIRE OF KARO is a multi-adventure pack with a complete campaign background based on the area of Cairo, Illinois. The time is twenty years after the collapse of civilization and Karo (as the locals call Cairo) is the hub of a growing empire based on revived river trade along the Mississippi.
This package includes a complete background to the growth of the empire, major personalities of the ruling clique, and even a detailed breakdown of the many merchants of the city and their business establishments. The scenarios begin with a series of military based adventures within the city and empire itself.
Scenarios continue to include a variety of adventure types in the ruins of a larger city, St. Louis, which is frequently visited on scavenging expeditions by the bolder general merchants of Karo. Player-characters can either lead their own expeditions or join one of the well-established expeditions to St. Louis.
THE EMPIRE OF KARO is not a complete game but an adventure package for use with the AFTERMATH(tm) game system. AFTERMATH(tm) is required for use of this package of role-playing adventures in a post-holocaust world.