The player takes on the role of Tommy Vercetti, a man who was released from prison in 1986 after serving 15 years for killing eleven people. The leader of the organization for whom he used to work, Sonny Forelli, fears that Tommy's presence in Liberty City will heighten tensions and bring unwanted attention upon his organization's criminal activities. To prevent this, Sonny ostensibly "promotes" Tommy and sends him to Vice City under the guardianship of mafia lawyer Ken Rosenburg to act as their buyer for a series of cocaine deals. During Tommy's first meeting with the drug dealers, an ambush by an unknown party results in the death of Tommy's bodyguards, Harry and Lee, and the cocaine dealer, including the death of Vic Vance (The main character of GTA:VCS). There is another survivor, the pilot of the dealer's helicopter, who flies off and escapes. Tommy narrowly escapes with his life, but he loses both the Forelli's money and the cocaine.
Tommy returns to his hotel room and phones Sonny to inform him of the outcome of the deal. Sonny, furious at the news, threatens Tommy about the consequences of messing with his organization. Tommy promises to retrieve the money and the cocaine and kill whoever was responsible for the ambush. Towards this end, Tommy meets up again with Forelli's lawyer Ken Rosenberg, who leads Tommy to contact a mid-level drug dealer and ex-military Colonel named Juan Garcia Cortez. Cortez expresses regret about Tommy's bad deal and promises that his own lines of inquiry are being made. Tommy also meets Cortez's daughter Mercedes, who becomes Tommy's girlfriend shortly thereafter.
While Tommy waits for the outcome of Cortez's investigation he meets British record producer Kent Paul, real estate mogul Avery Carrington and local free-lance criminal Lance Vance. Lance is eventually revealed to be helping Tommy because his brother/business partner was the dealer who was killed in the ambush, and he too is seeking revenge.
As time passes, Tommy befriends Colonel Cortez and begins to do regular work for him as an errand boy and hitman. One of his jobs for Cortez is to provide protection for a druglord Ricardo Diaz during a deal with the Cuban gang, which is later ambushed by a gang of Haitians. Tommy does his job and kills all the Haitians, which leads Diaz to begin hiring Tommy for his own agenda. Tommy takes this work because it pays well, in spite of his distaste for Diaz's character.
Tommy learns from Cortez that Cortez's own lieutenant, Gonzalez, was partially responsible for the ambush on Tommy's cocaine deal, and asks Tommy to kill Gonzalez with a chainsaw. Afterwards Cortez lays suspicion for the ambush upon Diaz. Tommy initially plans to continue the status quo to prepare for his own attack, but his hand is forced when Lance Vance attempts to take revenge on Diaz by himself and fails. Lance is captured and taken to a junkyard to be tortured. Tommy rushes across the city and rescues him. With the die cast, the two move quickly to raid Diaz's mansion with assault rifles provided by Lance. They wound and then execute Diaz outside his office. With Diaz dead, and Colonel Cortez fleeing the country on his boat to escape arrest, the established drug empires in Vice City quickly crumble and Tommy and Lance personally take over, becoming Vice City's cocaine kingpins.
Tommy becomes the head of his own organization, the Vercetti crime family, and the more powerful and rich Tommy becomes, the more Lance begins to exhibit paranoid and sociopathic behaviors, to the point that he begins to physically abuse his own bodyguards and constantly calls Tommy in states of hysteria.
