The game's story focuses on players assuming the role of John Tanner, an undercover FBI agent, as he investigates a car-smuggling ring across three countries, in order to identify and arrest its boss and learn who they are planning to sell a cache of stolen cars to. The game consists of primarily single-player modes of gameplay - "Undercover", the game's story mode; "Take A Ride", the game's free-roam mode, which allows players to explore one of the three cities at their own pace; and "Driving Games", a challenge mode consisting of three types of car-based games for players to try out, such as pursuing a fleeing criminal. Vehicles can be damaged over time, though players may freely leave their vehicle and switch to another within the current game world setting they are in at any time; the exception is vehicles that are mission critical to the game's story mode, as losing these constitutes automatic failure. A notoriety system keeps track of the player's actions - any unlawful action will raise this bar, with police pursuing the player if spotted by any, and the response to stopping them changing depending on the level of notoriety they have.
Driver 3 introduces new gameplay mechanics to existing ones including motorbikes and speedboats, swimming, a health bar, and gun combat. Combat focuses on the use of guns, based on real-life models and featuring a mixture of pistols, shotguns, assault rifles and sub-machine guns, and grenade launchers, to take down enemies; all weapons have a limit on ammo except for the lead character's personal weapon, but more can be found from dealing with enemies, or around the game world setting being played in during Take A Ride.
In Undercover Mode, players conduct a series of missions in which they must complete objectives, dealing with tasks such as escaping pursuers, reaching locations, and taking down culprits. At times, the player must complete objectives within a specific condition, such as a time-limit, with failure resulting in the player having to restart the mission. If the player completes a mission of the story or leaves Take A Ride, they can freely choose to edit a replay footage from their game with different camera angles and film effects . The amount of footage they can edit is pre-determined and restricted in size.
Undercover FBI agents John Tanner and Tobias Jones are sent to Miami to investigate the "South Beach" cartel headed by Calita Martinez , and her associates Lomaz and Bad Hand. To determine where the deal for the cars will take place, Tanner poses as a wheelman and infiltrates the cartel by recovering a car from a rival gang. After impressing Calita and earning her trust with a series of tasks, Tanner is assigned to assassinate "The Gator" for betraying the cartel.
South Beach relocate to Nice, France, after The Gator's presumed demise, to secure the remaining cars on their list.
