Timmy, his dad and the fairies get trapped in a board game created by Cosmo and must find a way to get out before Timmy's mom throws the game in a woodchipper.
Timmy awakes in his bedroom after his dad barges in saying that zombies were in the front yard. Looking out the window, Timmy tells his dad that his mom is having a yard sale and he gets out of bed when he realizes that his mom is about to sell his fish to Mr. Crocker. Timmy's dad then gets sucked into a board game Cosmo made about the average day of his dull life.
Timmy's mom announces that anything that is not sold in one hour will go into a wood chipper (which she announced was also for sale). Knowing no one would buy the board game and that it was going to go into the machine, Timmy enters the game with his fairies to rescue his dad. Before entering it, Sparky promises to do whatever he can to stop Timmy's mom from wood chipping the game.
In the game, Cosmo draws a card that forces the fairies to lose their wands. They then draw a card that takes them to the Laundromat to wash Cosmo's underpants. After squirting the underwear with bleach after it tries to eat Cosmo's face, they head to the Playground, where Timmy spins the roundabout with an unmarried lady on top of it. The lady, desperate to marry someone, lands on Timmy's dad's horse (which was a figurine now come to life) and asks the former to marry her, which he tells her no and that he already has a wife.
Hearing his dad's voice, Timmy rushes to where his dad is. His dad then takes off across a cliff and they take a winged car to fly over the cliff. They are forced to stop at the DMV (Department of Magical Vehicles) after Cosmo tells them that the car cannot fly unless if it's registered. Once they register it, they start flying until they feel the board vibrate from Timmy's mom moving it towards the wood chipper.
Sparky unplugs the wood chipper to buy the group time and he snatches the board from behind Timmy's mom's back. Timmy's dad and his horse get into the flying car and they head to the hospital, where Cosmo and Wanda had their first date after Cosmo accidentally ran her over the first time they met. Sparky and Timmy's mom fight over the game board and Sparky is scared when Timmy's mom growls back at him, making him let go and cause the board to land in the grass. In the hospital, Cosmo must first play a game that makes him take Wanda's heart out and then he reveals that the game ends when the duo share their first kiss.
The group escape the game at the last second before it enters the wood chipper completely. Mr. Crocker then gets sucked into a second version of the game.