Plot

In the summer of 1982, Sam Brenner (Adam Sandler) and Will Cooper (Kevin James) are thirteen-year-old who love playing in the local arcade. Brenner enters an arcade game world championship. At the event, the MC says that a time capsule will be launched into space containing a videocassette that includes scenes from the championships. Brenner and Cooper meet Ludlow Lamonsoff (Josh Gad), a child who's in love with Lady Lisa, the main character of the game Dojo Quest. Brenner succeeds in every game, but finally loses to Eddie Plant (Peter Dinklage) in Donkey Kong.

In the present, Brenner works for a company that installs home theater systems and Cooper is the President of the United States. In Guam, a U.S. military base is attacked. The soldiers try to fight back, but are easily defeated, and one soldier is abducted.

Brenner is sent to work at the home of Violet Van Patten (Michelle Monaghan), a divorcee who lives with her son Matty. Brenner heads to the White House after receiving a call from Cooper. To his surprise, he finds out that Violet is a Lieutenant Colonel. Cooper brings Brenner into the Oval Office to show him the attack in the base. Brenner says that the way the attack was carried out was like in the classic version of the video game Galaga.

Later, Brenner drives home when Ludlow suddenly appears inside his van. Ludlow takes Brenner to his home where he says that the aliens are sending creatures with classic video game designs to attack. Ludlow found a message using manipulated footage to explain their plans: The tape was found and seen as a threat; they are using the video games as a challenge. If they win three rounds, they will claim the Earth. They show the video to Cooper and determine that the next attack will happen in India but are too late; the Taj Mahal is attacked with Arkanoid paddles and another person is abducted as a trophy.

Brenner and Ludlow are brought in to "train" soldiers by showing them how to play these games. Violet shows Brenner and Ludlow that the pixels are taken down by strong light beams. The next attack will happen in London. The soldiers brace for attack in Hyde Park. Centipede appears in the sky. Brenner tells the men to shoot the head and anticipate the pattern, but they lack the skills, so more appear. Brenner and Ludlow take over with permission from Cooper and they defeat them. The aliens send a message to congratulate them on their victory, and give the Duck Hunt dog as a trophy, but remind that they are leading 2-1.

New York City is the place of the next attack. Ludlow and Cooper say that they need help. Brenner, Cooper, and Violet go to a prison to find Eddie, who is serving a sentence for counts of fraud. Cooper agrees to let Eddie out of prison and relinquish his taxes in exchange for his help. The team discovers that they are going to face the title character from Pac-Man and in order to succeed they need to defeat him three times. Violet presents them with four Mini Cooper cars based on the ghosts in Pac-Man, with the other car driven by the game's creator, Toru Iwatani.

In the downtown area Iwatani tries to appeal to Pac-Man as a son, but gets his hand bitten off instead. The remaining three chase after Pac-Man. He eats a power pellet, which gives him the ability to eat ghosts, and Ludlow escapes as it eats his car. Eddie defeats the first Pac-Man after catching up to him quickly, to the surprise of everyone. Eddie takes Pac-Man out a second time, but accidentally drives into the East River as he attempts the 3-1 sweep. Brenner takes up the chase but Pac-Man finds another power pellet. Brenner drives backwards through a parking garage. The power pellet wears off, and Pac-Man is defeated. As a result, the team is given Q*Bert as a trophy.

The team celebrate the victory, until the aliens send another message saying that someone cheated and the contest for the planet has been forfeited. Matty finds out Eddie used a speed cheat during the battle with Pac-Man. Eddie flees and Matty is abducted as a trophy.

The aliens cascade more video games on Washington, D.C. as they prepare to take over. Cooper joins the team, while Ludlow stays to fight. One of the aliens takes the form of Lady Lisa. She fights Ludlow until he says he loves her, and they share a kiss. Eddie comes to fight as well.

Brenner, Violet, Cooper and Q*Bert are brought up to the spaceship by Max Headroom where they have to face the title character from Donkey Kong, who rolls barrels at the group to prevent them reaching the captives. Matty reveals to Brenner what he found out about Eddie, and Brenner takes the hammer and throws it at Donkey Kong, destroying him. This causes the video games to freeze and then are brought back up to the ship, including Lady Lisa.

The team is recognized as heroes. A peace agreement has been made with the aliens. Q*Bert randomly transforms into Lady Lisa, to Ludlow's delight. Brenner and Violet become a couple, while Eddie gets a text message from Serena Williams and Martha Stewart.

A year later, Lady Lisa and Ludlow are married and have Q-Bert children, named Q*By. .