Smackdown the Slavers is based on the Advanced Dungeons & Dragons modules A1-4, Scourge of the Slavelords, by David Cook, Allen Hammack, Harold Johnson, Tom Moldvay. Lawrence Schick, and Ed Carmien. The HackMaster version is designed for characters levels 4-7.
From the Back Cover:
Prepare yourself my friend, for you are about to embark on a journey into a land where magic and monsters lurk in every darkened corner. This is not a place for the meek spirited or the wuss of heart. The Garweeze Wurld campaign setting is a land embroiled in an epic struggle that has raged for countless eons: where the forces of evil war against those of good, where law struggles to keep chaos in check, where adventure and the art of hack are the meat and drink of all who would seek to carve their niche in such a hostile, forbidding and unforgiving environment. This is the realm of the HackMaster roleplaying game.