In Need For Speed Underground you play the role of an undercover cop trying to catch street racers. After completing each objective you will earn money to buy cars, do performance upgrades, and add some visual tweaks to your ride. You do this by playing in career mode, where you will go around doing different tasks like taking out cops, winning street racers, delivering cars to a safe-house, or racing against the clock.
You start the game with some cash and are allowed to pick one of three cars. Once you do you will be given the backdrop to the game and given your first mission.