Bart trades places with a rich boy named Simon who looks just like him, but he discovers that Simon's half-siblings are planning to do him in to get his inheritance.
- A.I. Is a Crapshoot: Lenny's Vac-U-Bots have a convenient "Malevolent Sentience" setting.
- Brick Joke: When Mr. Burns tells about his siblings and their early deaths, he mentions that most of them died from eating poisoned potatoes. In a later scene, Queenly offers her brother a potato.
- Eviler Than Thou: After Devon and Queenly think they got rid of their half-brother, Queenly tries to make Devon eat a poisoned potato when he declares they'll split the inheritance.
- Jerkass Has a Point:
- Homer is right to be mad at Bart for playing one prank too many as is everyone else.
- Lisa also qualifies by pointing out that Simon is nothing like Bart.
- Karma Houdini: Devon and Queenly never receive any comeuppance for trying to get rid of their half-brother. Or at least Queenly, assuming if she succeeded in killing Devon with a poisoned potato.
- Out-of-Character Alert: Lisa becomes suspicious of "Bart" when he starts acting and speaking in a refined manner.
- Prince and Pauper: Bart and Simon. This is then Played for Laughs when an older man who looks like Bart as an adult shows up at the bathroom and shows them he's married to a woman...who looks like Milhouse.
- The Resenter: Simon says his half-siblings Devon and Queenly resent him because their father left their mother to marry Simon's.
- Spoiled Brat: Queenly is upset for being given a car that isn't the same one she wanted and rants that it was her worst Martin Luther King day ever.
- The Unfavorite: Bart has become this throughout the first half of the episode.
- We Want Our Jerk Back: Albeit Lisa was reluctant to admit it to Simon.
- Would Hit a Girl: When Lisa hit Simon, she told him Bart would have defenestrated her in retaliation.
- Wouldn't Hit a Girl: It came as a shock to Simon that Bart would.
- Would Hurt a Child: The mob at Lenny's party were fully on board to kill Bart over his prank with the Vac-U-Bots.
- You Are Grounded: Marge tries to do it to Bart by first taking away his TV and video game privileges, which he points out she already did. She takes away his non-dice board game privileges as a result.
- Youngest Child Wins: Mr. Burns is his parents' youngest child and inherited their fortune because his siblings had premature deaths.