The game setting is a medieval fantasy world similar to that of the high fantasy seen in The Lord of the Rings. The demons and abominations of nature who reside in the underground kingdom of Cadash have not forgotten that, thousands of years previously, they once shared the light with humans. Then one rose among them who was especially powerful, a demonic wizard born of a human woman – the Balrog (Baarogue or Baalogue in the arcade version, and Barlog in the TurboGrafx version). The Balrog promised his followers they could, in time, emerge from their subterranean prison and rule the world of men, taking revenge on humans for their prior defeat in battle and subsequent exile, if the Balrog could mingle his blood with that of a human king. The Balrog and his demonic armies gathered in force over the centuries, and are now powerful enough to emerge to the surface and make war with the unprepared human kingdoms which had not known war for millennia, all of which quickly fall to the Balrog. The human world is almost entirely laid to waste by the Balrog. However, this was not enough for the Balrog, whose prize is the mightiest of all human kingdoms, the Kingdom of Dirzir. One night, the beautiful Princess Salassa is kidnapped by the Balrog from the Keep of Deerzar, the capital city of Dirzir, and taken underground to the dreaded Castle Cadash. There the Balrog plans to initiate the ritual which would magically bind himself to the human princess, becoming all-powerful and invincible. Dilsarl, the distraught and helpless elderly King of Dirzir, has vowed to give his entire kingdom to the one who would rescue his beloved only daughter, and many brave heroes have disappeared into the depths of Cadash on this quest.