Zapped! begins at Ralph Waldo Emerson High School. The nerdy, but hunky, Barney Springboro, works on a scientific experiment with lab mice until his friend and shady yearbook photographer, Peyton Nichols, tells him it’s time for a class assembly. Once at the assembly, Peyton mocks Barney’s lack of interest in finding a girlfriend. Peyton is Mr. Studmuffin, and later that day, he seduces a school administrator named Corinne Updike.
The school’s class president, Bernadette would like Peyton take photographs of Barney posing with his genetically modified orchids he has been growing for the school’s principal, Walter Coolidge. He agrees to do it, but back in the lab, Barney drops one of the beakers containing the mice’s feeding solution. A cloud of smoke pops out of it, and knocks Barney unconscious.
He wakes sometime later, and returns home. There, his stereotypical uptight 80s mom lectures him on his tardiness and for his lack of a girlfriend. As she yells at Barney, his bedroom door mysteriously slams shut.
The next day in English class, Barney fantasizes about Jane Mitchell, one of the popular girls at his high school. The teacher unexpectedly calls on him; breaking his concentration on the fantasy. He scrunches his eyebrows, and the map above the chalkboard to falls on her head.
That afternoon, Peyton, ever the male whore, asks Jane out on a date. She can’t because she has a boyfriend in college. Barney is there too, and as he stares at her chest, her shirt rips open by itself. All three are a bit confused, but the boys are also turned on.
Back in the lab, Barney experiments with his newfound telekinetic abilities. He manages to levitate various objects across the room; unaware that Bernadette and Peyton are spying on him through the window. They confront him over it. Barney wants to keep his powers secret, but Peyton want to use them to benefit himself.
Barney goes home to practice more. There, he sends a very familiar looking spaceship through a fish tank., and then animates his ventriloquist dummy; scaring the bejesus out of his mom to the point she thinks he’s possessed.
It’s now the day of the big baseball game, and Barney’s busy helping the school’s team hit the winning home run. While he’s there, Principal Coolidge tires to enter Barney’s lab to check progress on his orchids, but doesn’t have the key. So, he leaves.
Barney then agrees to let Bernadette write a report about him for her sister’s college science journal. They spot Mrs. Burnhart sneak into Barney’s lab where she uncovers a pot of Peyton’s marijuana he hid behind the orchids. She runs off to get Principal Coolidge, but they return to discover the marijuana isn’t there.
The baseball coach Dexter Jones watches Barney and Bernadette stuff the plants in the incinerator. The smoke causes him to become high as a kite to the point he imagines his abusive wife chasing after him while he rides a bicycle with Albert Einstein dressed as a Viking warrior.
That weekend, Barney, Peyton, and Bernadette go to a pre-graduation celebration at an amusement park. To prove his manhood, Peyton bets Jane’s boyfriend, Robert, he can out drink him; the first to puke loses. When they get on a spinning ride, Barney speeds up Robert’s car until he vomits. He loses money from the bet, but these are two rich white boys. They will be okay.
That night, Peyton brings Jane home where he seduces her with his maturity. That must be it because he’s really not a player with any kind of skills. Elsewhere, Barney and Bernadette have dinner, and clearly, they are falling for each other. They spend the next afternoon together in the park too. Afterwards, they return to Barney’s lab, and make sweet teenaged love.
The next Monday, Jane dumps Peyton because she regrets sleeping with him, and she goes back to Robert. Robert, on the other hand, wants to win back the money he lost to Peyton, and he invites him to a casino-themed college fraternity party. Peyton begs Barney come with so he can manipulate the roulette wheel. Bernadette doesn’t like Peyton using Barney, and becomes angry when Barney agrees to help him gamble.
While at that party, Barney gets distracted while manipulating the roulette ball, and winds up levitating the whole wheel instead. He leaves, and tries to call Bernadette, but she refuses to answer she’s so damned mad at him. Barney then does what any teen nerd does, he spends the night in his lab drinking whiskey.
The next morning, a hung over Barney apologizes to Bernadette, and the two agree to meet at the prom later that evening. Before he gets the chance to leave for the dance, he finds his mom has hired two priests to perform an exorcism on him. Barney uses his ventriloquist dummy to scare and then chase them around the house. He then sneaks away. I’m sure his clueless mom doesn’t have a clue there’s a prom that night he’s probably headed to.
After Peyton and Jane get crowned the prom king and queen, Jane rejects Peyton once again. Barney dances alone with Bernadette, but Peyton ruins that moment when he barges in with two tickets to beautiful Las Vegas, Nevada. He wants to make a fortune there using Barney’s gift to swindle the casinos.
Robert then confronts Peyton about the roulette game, and Peyton, ever the classy guy, apologizes. He then gives him a bunch of nude photographs he took of Jane. Enraged, Robert attacks him, but Barney steps in, and summons a large gust of wind in the room. It tears off all the students’ clothes, and sends everybody scuttling outside.
In the chaos, a fire hose knocks Barney out. When he wakes up, he believes that he’s lost his new powers. However, when he and Bernadette leave the prom, he grabs her by the waist, and sends them up into the night sky in a cloud of magical dust.