The game is based on the Disney film The Black Cauldron (1985), which itself was based upon the first two books in Lloyd Alexander's Prydain Chronicles - 'The Book of Three' and 'The Black Cauldron'.
The game has multiple alternative endings, depending on who jumps into the black cauldron (Taran, Gurgi or the Horned King), and what the player agrees to receive from the three witches in exchange for returning the cauldron. One of them is that Gurgi willingly sacrifices himself by jumping into the black cauldron, like he does in the film, thus destroying both the evil power of the cauldron and the Horned King, but getting himself killed. Afterwards, the player has the option to ask the witches to revive Gurgi in exchange for returning the cauldron, as Taran does in the film. The best ending is achieved by making the Horned King throw himself into the black cauldron, thus destroying both himself and the evil power of the cauldron, and later receiving the magical sword Dyrnwyn back from the three witches in exchange for returning the cauldron.