The last episode of season three starts with the impossible: George has gotten laid. Unfortunately, his amorous conquests are the nieces of the duke of Wellington, who has personally sworn to kill anyone who defiles one of his relatives. George is terrified of fighting the duel so Baldrick suggests he should get someone else to fight it for him, and suggests Blackadder, who of course, is not pleased. However, when he remembers his identical Scottish cousin, who just happens to be a homicidal maniac, MacAdder, is in town he changes his mind. Of course, MacAdder refuses to fight and Blackadder must pretend to be the prince and fight the duel himself. Wellington turns out to be a blustering idiot, and the duel turns out to be fought with cannons, and Blackadder is shot. But all is well! The cannon ball hit his cigarillo case, and everything is fine! George, pretending to be the butler, Blackadder, steps out of the shadows to reveal he is the prince, but Wellington shoots him in his anger. At that moment, the mad king appears, looking for his son, and Edmund, still in the prince's clothes, goes off with him, presumably to live the rest of his life as the Prince Regent.
But wait...George isn't dead after all! The bullet hit HIS cigarillo case—oh, wait, he must have left it on the dresser. Bugger.
- Acting for Two: Rowan Atkinson as both Blackadder and MacAdder.
- Ax-Crazy: MacAdder.
Edmund: He's mad. Mad! He's even madder than the mad Jack MacMad. The winner of last year's Mister Madman Competition.
- The Bad Guy Wins: An odd, yet awesome example of the trope. Blackadder may be the protagonist, but he's certainly a bad guy. And he gets to live out the rest of his life as the Prince Regent, and eventually the king, while George dies. However....it's awesome.
- Buffy Speak: One of the few times Blackadder is so mad he can't even think of a simile.
Blackadder: We're about as similar as two completely dis-similar things in a pod.
- Can't Get Away with Nuthin' : Prince George, who has had no luck with the girls throughout the series, finally gets laid. And is killed for it.
- Dreaming of Things to Come: Prince George claims to have had a dream of an Eagle that flew around the room 3 times and got into bed with him, before turning into a large black snake and stealing all the covers.
- Duel to the Death: Prince George is challenged to one.
- General Failure: Wellington, who believes war is about shouting and stations his men in Alaska to try and catch Napoleon in case he tries to sneak up on them.
- Leaning on the Fourth Wall:
Edmund: Yes, I'm afraid my ambitions stretch a little further than professional idiocy in West London. I want books written about me. I want songs sung about me. And then, hundreds of years from now, I want episodes from my life to be played out weekly at half past nine by some great heroic actor of the age.
Baldrick: (smiling) Yeah, and I could be played by some tiny tit in a beard.
- Pocket Protector: Taken to comedic extreme. Blackadder's cigarillo case saves him from death by cannon fire.
- Prince and Pauper: Edmund and George switch coats and wigs and pretend to be each other. Lampshaded by George:
: This is just like that story, 'the Prince and the Porpoise'. Edmund
: And the Pauper
: Of course. 'The Prince and the Porpoise
and the Pauper.'
- Puff of Logic: George doesn't notice he's dead until he realizes he forgot his cigarillo case.
- Record Needle Scratch: Sappy music plays as George and Edmund lay dying, and stops when they both sit up.
- Uncanny Family Resemblance: Blackadder and MacAdder. Everyone is astounded how alike they look!
- Violent Glaswegian: MacAdder.