The player character is a young assistant pig keeper, Taran, undertaking a quest to stop the evil Horned King, who seeks for Hen Wen, the magical pig of the wizard Dallben, for her visionary abilities. With these abilities, the King would be able to discover the Black Cauldron and rule the land. Taran is tasked with taking her to safety, but the game differs from the plot of the film in the first of several ways in that Taran is able to succeed in doing so. The game actually featured plot branches and Multiple Endings depending on many variables, such as whether Hen Wen the pig was saved, how the cauldron was destroyed, and what reward was chosen afterwards. This use of multiple endings predated the more famous use in Maniac Mansion by a year.
In order to make the game more accessible to children, Sierra used an innovative idea that would not re-appear in the genre for the next 10 years: The text parser that was used in the company's earlier graphic adventure games was removed in favor of the function keys that performed various actions: F3 would choose an inventory item, F4 would use it, F6 would perform "Use" near the character's location, and F8 would "look." The simplification of the two actions "Look" and "Use" was not reused in Sierra's later games. However, it somewhat resembles the control system of other later, simpler point and click adventure games, such as the King's Quest VII: The Princeless Bride or The Dig whose interfaces only consisted of "Look" and "Use." Being based on a Disney film, the graphics present some relative "flexibility," compared to the monolithic and straight backgrounds of previous and later games.
This Video Game contains examples of:
- Canon Welding: The manual makes references to the events in The Foundling and Other Tales of Prydain when telling of how Dallben came to be and from Taran Wanderer showing that Dallben found the infant Taran on a battlefield among the bodies of what were assumed to be his now dead parents.
- Likewise, the endless food wallet originated in the source material, only it was used by Gurgi rather than Taran.
- Cool Sword: Dyrnwyn, which can chop right through metal, although in keeping with Sierra's non-violence policies only stuns bad guys for a few seconds.
- Demoted to Extra: Taran's companions are given very reduced roles compared to the film, due to the limits of personal computers at the time. Eilowny only follows Taran around in the secret passages of the Horned King's castle, then disappears from the plot after they find a certain room. Fflewddur exits his cell and just disappears into thin air. Gurgi will appear randomly in the forest, but will only show up suddenly to help in certain endings.
- Gameplay and Story Segregation: The best ending of the game has Taran getting the magic sword back from the witches and using it to become an unbeatable warrior. In the game it only knocks out bad guys for a couple seconds.
- Golden Path: The best ending is achieved by doing everything Taran did wrong in the movie: Getting Hen-Wen to safety and not letting the Horned King get ahold of him (but not before getting a magic pouch that ensures you will never run out of food from under the bridge. Something that will disappear if you don't get it before this), not using the magic mirror on the witches, and not attempting to throw yourself into the cauldron. Instead, you must find a hidden path to the bellows behind one of the wine barrels, then use the magic mirror on the king to cause him to commit suicide by running into the cauldron and throwing HIMSELF into it. You will then be able to get the magic sword back and become the warrior Taran always wanted to be.
- Magic Cauldron: The titular Black Cauldron, naturally. The game (like the film) makes the Cauldron more central than it was the books (where it's destroyed in book two rather than at the end of the series).
- The Mirror Shows Your True Self: The Fair Folk give you a magic mirror that shows the true nature of anyone who looks into it, and has a different message if used when the party members from the movie are around. One way to defeat the Horned King is to show him a magic mirror. He will be so horrified at his own evil that he'll jump into the Cauldron and kill himself!
- Multiple Endings: There are a lot of ways the game can end. You could have Gurgi die and be brought back to life. You could end up getting the magic sword back. In some it's about holding out for the best possible offer.
- Never Smile at a Crocodile: The Horned King's castle is surrounded by a moat full of killer crocodiles. One of the ways to get in is to swim around them and climb the wall.
- Non-Standard Game Over: If you fail to get Hen Wen before she reveals the location of the Black Cauldron to the Horned King, the game ends immediately.
- Pig Boy Needs Food Badly: Regular eating (and drinking) is a requirement. (Something repeated only once in King's Quest V: Absence Makes the Heart Go Yonder!, and even there, only at a certain point.) Luckily there's a fair amount of food: 3 meals worth of bread, an apple, and cookies. Water can be filled almost anywhere (except at the Horned King's castle. You can fill the water in the moat there, but it will kill you if you drink it.) However, once you run out of food it's only a matter of time until you starve to death. Unless you happen across a certain magic pouch under the bridge just to the south of Dallben's cottage. This pouch will produce food for you forever. However, you can only acquire it while escorting Hen-Wen to the hidden cottage. If you return to the bridge after you either succeed or fail in this task, it's gone forever.)
- The Pirates Who Don't Do Anything: Despite calling attention to the Horned King's menacing, cleaver-wielding cook, he doesn't actually do anything dangerous.
- Tap on the Head: Hitting the Horned King's guards with the magic sword dazes them for a few seconds, then they get back up and keep chasing you.
- Unwinnable by Design: Actually a little more merciful than other Sierra titles, especially from that era. For instance if you try filling your water bottle from the river near the Horned King's castle it'll be pulled out of your hands, but you can actually follow the river downstream to get it back. If you get captured while carrying the magic sword, though, it's possible to get all your other stuff back but the sword's gone forever. Sorry.