Trivia: The film has many subtle allusions to popular games and gaming archetypes. For example: -Many elements of the plot (such as the hot-rod car and Gary's dog Bastion) are references to game-pieces from the game Monopoly. -The scene where Annie digs a bullet out of Max's arm and then sews it up is both a reference to the Monopoly thimble-piece and the children's game Operation. -During the chase scene, there are frequent shots where the camera is mounted to the back of the cars in such a way to emulate car-racing video-games. -The music includes several cues done in an 8-bit Nintendo video-game style. -Establishing shots are filmed using a photographic technique called "tilt-shift", which makes live action locations look like miniatures, and thus, like board-game pieces. Etc. There are dozens of these types of references throughout the film.
Trivia: In the scene where Max and Annie talk about their potential future child, there's a throwaway line about child-actors not amounting to much later in life - a bit of an inside joke, as Max is played by Jason Bateman, the rare child-actor whose career actually improved after he became an adult.
Trivia: R.F. Daley, the actor who portrays Tats, is the father of John Francis Daley, the co-director of this movie.
Trivia: Major Spoilers: In the beginning of the movie, when Max and Annie are kissing on the subway, there's a scrolling LED display behind them. If you pay attention, the screen reads "Don't trust Gary." This is (pretty blatant) foreshadowing towards the twist where Gary is revealed to have staged the kidnapping of Brooks to create his own "game night."
Trivia: The trivia announcer at the start of the film is played by co-director John Francis Daley in a cameo.
Trivia: Danny Huston plays the mobster Donald Anderton, who hosts an underground fight club. He briefly mentions that his fighter is named "Logan." Danny Huston also played William Stryker in "X-Men Origins: Wolverine," in which he was the commander of Wolverine - aka "Logan." This is either a bizarre coincidence or a subtle reference... either way, it's pretty amusing.
Trivia: Minor spoilers: The "Bulgarian" agrees to let everyone but Brooks go towards the end, because Brooks is the only guilty one, and he intends on killing Brooks with a knife while he is restrained. In the TV show "Dexter", the titular character only kills criminals - people who are guilty - and he does it with a knife while they are restrained. Both the Bulgarian and Dexter are played by Michael C. Hall.
Trivia: Spoilers: There's a pretty subtle bit of foreshadowing in Gary's house. When he's seated and the group is playing Jenga, if you look behind Gary, there are two old-fashioned guns on the mantle. The way the shots of Gary are framed throughout the scene, both guns are pointed right at him several times. Later in the movie, Gary ends up being shot twice by two different guns - once by a gun loaded with blanks and once by a gun loaded with live ammunition.
Answer: Brooks was kidnapped by Gary's fake kidnappers. Everything to do with his kidnapping was set up by Gary. Gary did it to make people realise he'd be fun at their game night. However, Brooks was in league with the actual criminals and assumed they were responsible, which is where the mix-up happens. Eventually, the real criminals show up in the third act. Basically, it's two separate storylines that converge at the end through a comedy of errors.
TedStixon