The game primarily tested the memory and comprehension skills of the contestants. The first round, "Brain Tease", started with six contestants trying to quickly figure out the numbers conveyed visual puzzles, entered on keypads. Then, sans the two lowest scoring contestants (who have to go down ... the Brain Drain!), the remaining four in turn played Level 2, where they were told a story from the "Big Book of Truth" and had to answer questions based off it, locking in by sitting on a chair covered in Whoopee Cushions. The first to answer incorrectly is greeted by farts, and gets pulled backwards through the (paper) teeth of a giant mouth made to look like Jeff's face. This then continued until someone else answered incorrectly, who also faces the same fate.
For the final round, Level 3, the two contestants play a matching game with eight pairs of pictures from the story. If a player fails to match, the other player can automatically win if they make a match on their next pick, who then got to play the Bonus Round.
Its third and final season brought some major changes; along with being moved to Nick @ Nite (before being moved back to Nickelodeon in October 2011, and a brief burn-off of remaining episodes on Nick Toons a few years later), it became Family BrainSurge, played with five teams of two. Other adjustments included only playing 4 puzzles in Level 1, and the addition of a lifeline in Level 2.
This show contains examples of:
- Amazingly Embarrassing Parents: One story in Level 2 is all about this trope. Jeff tells how his parents did insanely humiliating things to him when he was growing up.
- On picture day, his mother wiped his face with saliva to clean it, and planted a lipstick kiss mark on his forehead right before his picture was taken.
- When he was on the soccer team, his parents would dress up as cheerleaders. Not only that, but his father wore stinky socks in sandals, and his mother would yell, "I love you, Jeffy-poo!" through a megaphone, causing his teammates to laugh at him.
- His parents would wake him up in the mornings by making rooster noises, even wearing rooster costumes as seen in the animation, including when Jeff had sleepovers.
- His mother told his friends that he still sucked his thumb until he was 8.
- Once at a department store, his father couldn't find him, so he made an announcement over the store loudspeaker to tell everyone there that he was looking for his little boy. And that was when he was 17.
- But what Jeff considers the worst out of these is that his mother made him go to the store and buy diarrhea medicine while a cute girl was working the register.
- The Announcer: Erin Fitzgerald in the first two seasons, replaced by John Cramer for Family BrainSurge
- Aside Glance: Jeff does this, alongside a smirk and a head shake, every time he claimed that all his Level 2 stories were "all 100% true".
- Bonus Round: The Brain Trip: three floors, with 4x4, 5x5, and 6x6 grids. The winner has to memorize a pattern on the first grid, and then correctly step through the correct sequence. If done correctly, the same is done through the 5x5 and 6x6 grids. However, this all has to be done in 90 seconds (the clock does stop between floors), and making a mistake anywhere sends you back to the start. Each stage has a prize attached (won regardless of whether the round overall is won or lost), and completing all the floors in time awards a grand prize (usually a trip).
- Celebrity Edition: With Nickelodeon stars playing for a chance to win a prize for an audience member in the Bonus Round.
- Family BrainSurge also included celebrity editions, in which non-Nickelodeon celebrities competed with their family members for charity, but also get a chance to win prizes for a non-participating family member in the bonus round.
- Counting Sheep: One round in Level 1 involves Jeff sleeping and his dream shown to be this trope. A various number of sheep are running and jumping over a fence, and after they stop, the players have to guess how many sheep there were. After they submit their answers, the screen then shows Jeff waking up and then screaming in horror as he sees the sheep in his dream are somehow in his bed. Then the number of sheep are counted, thus showing the correct answer.
- Covered in Gunge: It wouldn't be a Nickelodeon show without unnecessary messiness: contestants eliminated in the first two rounds, and those who run out of time on the bonus round, have to go down the "Brain Drain" — a slide made to look like a human ear, with "earwax" foam. Even some of the audience members can get up close to the brain drain and get their hands covered in goo! Bonus round winners get the more traditional Nickelodeon green slime.
- Eject the Loser: The Brain Drain, and the part where you get sent backwards on a chair through a wall (of teeth).
- Game Show Host: Jeff Sutphen
- Golden Snitch: In the first round, the final question is worth 100 points, more than the other ones combined.
- Gum In Hair: This happens in one of Jeff's "true stories" with his date.
- Gravity Is a Harsh Mistress: In a skit that appears frequently in the first round, in which players guess how many somersaults a trapeze artist does, this happens to him when he's done. He even does an Oh, Crap! expression and waves goodbye to the camera, before having an Impact Silhouette on the ground.
- I Want My Mommy!: In a guessing session involving parachutes, Jeff's character cries out "Mommy!" as he dives to the ground with his parachute unfolding.
- Lifelines: In Family BrainSurge, each team is allowed one "Brain Fart" in Level 2, allowing the team to get help from other family members in the audience. However, what they say is automatically locked in as the team's guess. In the celebrity episodes of this format, random audience members were used instead.
- Loves Me Not: One guessing portion in Level 1 involved a girl finding a flower on a bush, doing this trope, and getting frustrated when she ends on not. Then the players have to guess what flower with the number of petals would result in loves me not, with examples of flowers shown, and the flower with the odd-numbered petals is the correct answer.
- No Name Given: Levels 1 and 2 were simply known as such, until Family BrainSurge when they became "Brain Tease" and "Brain Fart", respectively.
- Open-Fly Gag: One episode involved a guessing skit that involves note passing. When the guessing is over, Jeff gets a note of his own, and it tells him that his fly is down. He looks a bit flustered by this.
- Passing Notes in Class: A frequent guessing portion in Level 1 involves this trope, in which a row of girls hand notes to a row of boys in front of them. The teacher would then ask one of the boys to give her the note he has, and asks who wrote it, and it's up to the players to guess which one of the girls passed the note to this boy. After the guessing is over, the teacher reads aloud the note which reveals which girl did it, thus providing the answer.
- Player Elimination: In Level 2, players have to answer a question from the outrageous story Jeff told, and they sit down to see if they were right. If they guess wrong, a fart noise is heard and the player is dragged backwards into the cardboard mouth, eliminating them from the rest of the game.
- Screw This, I'm Outta Here!: On one celebrity BrainSurge episode, when Matt Shively correctly guesses and wins the Knockout round, Ashley Argota knew what's coming and prepares to get eliminated. Turns out she was right...
- Time Keeps On Ticking: During the Bonus Round, if you make a mistake, you have to start over. You get to see the pattern again, but you're still on the clock.