Players can steal vehicles, (cars, boats, motorcycles, and even helicopters) partake in drive-by shootings, robberies, and generally create chaos. However, doing so tends to generate unwanted and potentially fatal attention from the police (or, in extreme cases, the FBI and even the National Guard). Police behavior is mostly similar to Grand Theft Auto III, although police units will now wield night sticks, deploy spike strips to puncture the tires of the player's car, as well as SWAT teams from flying police helicopters and the aforementioned undercover police units, à la-Miami Vice. Police attention can be neutralized in a variety of ways.
A new addition in the game is the ability of the player to purchase a number of properties distributed across the city. Some of these are additional hideouts (essentially locations where weapons can be collected and the game saved). There are also a variety of businesses called "assets" which the player can buy. These include a film studio, a dance club, a strip club, a taxi company, an "ice-cream delivery business" (acting as a front company), a boatyard, a printing works, and a car showroom. Each commercial property has a number of missions attached to it, such as eliminating the competition or stealing equipment. Once all the missions for a given property are complete, the property will begin to generate an ongoing income, which the increasingly prosperous Vercetti may periodically collect.
Various gangs make frequent appearances in the game, some of whom are integral to story events. These gangs typically have a positive or negative opinion of the player and act accordingly by following the player or shooting at him. Shootouts between members of rival gangs can occur spontaneously and several missions involve organized fights between opposing gangs.
Optional side-missions are once again included, giving the player the opportunity to make pizza deliveries, drive injured people to a hospital with an ambulance, extinguish fires with a fire truck, deliver passengers in a taxi, be a vigilante, using a police vehicle to kill criminals, and the ability to drive a bus, transporting fare-paying passengers. Monetary rewards and occasional gameplay advantages (e.g. increased health and armor capacity and infinite sprinting) are awarded for completing different difficulty levels of these activities. Different sums of money are awarded for landing trick jumps in motorcycles or fast cars depending on the number of flips and height achieved.