Max, a competitive gamer portrayed by Jason Bateman, and his partner Annie, played by Rachel McAdams, quickly bond over a trivia competition at a bar, leading to a whirlwind romance and eventual marriage. Their journey to parenthood proves difficult as they grapple with various challenges, including Max's constant comparison to his more successful brother, Brooks (Kyle Chandler). This rivalry is particularly ignited during their regular game nights with friends, including Ryan (Billy Magnussen), Kevin (Lamorne Morris), and his wife Michelle (Kylie Bunbury).
Brooks arrives at a game night in style, showcasing his flashy Corvette Stingray, which only serves to highlight Max's insecurities. Annie, feeling similarly annoyed by Brooks' arrogance, devises a plan with Max to outsmart him at a game night he offers to host at his rented house. Their mission to keep their game nights secret from their neighbor Gary (Jesse Plemons), a former police officer who has been estranged from the group since his wife left him, adds to the tension.
When the guests arrive, including Sarah (Sharon Horgan), Ryan's new date, Brooks surprises everyone by announcing a live-action role-playing mystery game, enticing them with the promise of his car for the winner. But the atmosphere shifts dramatically when a pair of masked intruders burst in, leaving the guests initially bewildered and thinking it's part of the game. As Brooks is forcefully taken from the house, the couples begin piecing together the clues left behind, believing it to be a part of the intended mystery. Here begins a frantic race as Max and Annie call upon Brooks' phone's GPS to track him down while Ryan and Sarah pursue leads related to the game premise.
Their adventure takes a darker turn as they confront deadly scenarios. Discovering Brooks in a shady bar tied to an illegal scheme involving a sought-after Fabergé egg, they mistakenly shoot at a fictionalized threat, discovering that their predicament is all too real. As they dive deeper, they uncover Brooks' double life in the black market and his connection to a mysterious figure known only as the Bulgarian (Michael C. Hall).
As they navigate one dangerous encounter after another, the group finds themselves grappling with their own fears and insecurities. After an unexpected rescue by Gary, who reveals his elaborate ruse to reconnect with the group, the challenge intensifies when they learn that Brooks has been captured by the true criminals seeking the egg. In a high-stakes climax, Max and Annie hotwire Brooks' Corvette to thwart an outgoing flight that threatens to take him away.
Months later, Brooks finds himself under house arrest yet still managing to profit from his previous dealings. The close-knit group celebrates as Annie finally discovers she's pregnant, but the celebration is interrupted by armed assailants ready to crash their game night.
As the end credits roll, they reveal Gary's scheming involvement, and a post-credits scene teases further encounters that blend humor and chaos.
