The game is a prequel to LEGO City Undercover and tells the story of Chase McCains's (and other characters from that game) beginnings as a police officer in Lego City: Chase McCain is a rookie cop fresh from the academy who joins the Force of the Lego City Police Department. He must make himself a name in the police ranks as he solves more and more difficult cases.
LEGO City Undercover: The Chase Begins is set in an open world (Lego City). Chase can use all kinds of cars he sees on the streets. He also has access to police equipment and gets more as he progresses. He is also a master of disguise as he can use costumes, which need to be found first, to get new abilities (as a thief, he can use a crowbar to open doors that are normally locked, for instance). He also knows martial arts techniques that come in handy when facing bad guys. McCain is also able to use parcour skills, allowing him to climb up a building on the facade, amongst other acrobatic stunts.