Prince Duncan is the main hero, and star of the first two games in the Dark Castle Series, Dark Castle, and Beyond Dark Castle.
Involvement in Dark Castle[]
Main Article Dark Castle
Yet unnamed, our hero, decides to take on the infamous Black Knight. After collecting the Shield and Fireball, he makes his way to the Black Knight's Throne Room, and then proceeds to topple the Black Knight's Throne.
Involvement in Beyond Dark Castle[]
Main Article Beyond Dark Castle
With help from Merlin, Prince Duncan finds his way "Beyond" Dark Castle, to a large Ante Room located behind the Black Knight's Throne. The room has 5 pedestals, all of which need to be filled with the mysterious Orbs, in order to open the gate to the Final Battle.
See: Beyond Dark Castle Advanced Ending
Involvement in Return to Dark Castle[]
Main Article Return to Dark Castle
In Return to Dark Castle, Duncan is not the main character, instead, his nephew, Bryant holds the position.
Spoilers
Based on the Advanced ending to Beyond Dark Castle, and the intro to Return to Dark Castle, we can assume that Prince Duncan, is still the Black Knight, and Bryant may be on a quest to defeat him unknowingly.
End Spoilers
Prince Duncan as a character[]
Prince Duncan never talks, except to make "woah" sounds, and such. By the sound of the intro of Return to Dark Castle, there is a chance he may not actually be a prince, and just calls himself that. Additionally, in the first game he was unnamed, and was only given a name in the second game. Is Prince Duncan crazy for attempting to topple the Black Knight's throne? Or is he just trying to be heroic?