Tupac Shakur, a rapper and actor who built a career on controversy, died of wounds yesterday from a drive-by shooting last Saturday. He was 25 years old.

Mr. Shakur, who lived in Los Angeles, had been in critical condition at University Medical Center in Las Vegas since Saturday. That night as he was leaving the Mike Tyson-Bruce Seldon prizefight, a Cadillac pulled up alongside the BMW in which he was riding and he was shot four times. His right lung was removed on Sunday. No arrests have been made.

Mr. Shakur was a complex and sometimes contradictory figure, with a career featuring million-selling albums, gunshot wounds and run-ins with the police. He was an intelligent, vivid writer who had studied acting at the High School of Performing Arts in Baltimore; he was an accomplished rapper with a husky baritone and crisp enunciation. He was also a convicted sex offender, and the words ''Thug Life'' and ''Outlaw'' were tattooed on his body.

''It's really unfortunate that the violent perception that the world has of that young man may be exacerbated by the way he died: art is being confused with real life,'' Mr. Shakur's lawyer, Shawn S. Chapman, said yesterday in Los Angeles. ''There was this wonderful, charming, bright, talented, funny person that no one is going to get to know; they are just going to know this other side. Hopefully, this will have some positive effect on people -- the gang members -- who are shooting each other.''

In some raps, Mr. Shakur glamorized the life of the ''player,'' a high-living, macho gangster flaunting ill-gotten gains. But in many others, sometimes on the same albums, he portrayed the gangster life as a desperate, self-destructive existence of fear and sudden death. He described gangsterism as a vicious cycle, a grimly inevitable response to racism, ghetto poverty and police brutality.

''All we know is violence,'' he declared in ''Trapped.'' In an interview with Vibe magazine this year, he said children should be told that ''because I'm talking about it doesn't mean that it's O.K.'' But he also reveled in his notoriety, particularly after he was released from jail.

With many raps about killing policemen (usually in self-defense), Mr. Shakur offered prime examples for groups that wanted to clean up rap lyrics; he also considered himself a target of police harassment. At the same time, he sold millions of albums and reached No. 1 on Billboard's pop-albums chart. Long before his death, his career raised questions about hip-hop's devotion to ''realness,'' the notion that a performer has to live (or have lived) the life he raps about.

''Although some may say that Tupac laid down in the bed he made, it is always unfortunate when someone with talent dies at such a young age, regardless of circumstances,'' said Geoff Mayfield, director for charts at Billboard, the music's industry trade magazine. ''Hopefully, the reaction to what has happened will dampen enthusiasm for violence among those who looked up to him, rather than promote it.''

Tupac Amaru Shakur was born in New York City, the son of Afeni Shakur, a member of the Black Panthers who was in jail on bombing charges while she was pregnant with him; she was acquitted. He grew up in the Bronx, then moved with his mother to Baltimore, where he studied acting at the High School of the Performing Arts. There, after a friend was shot while playing with guns, he wrote his first rap, about gun control, and began performing it. He dropped out of high school (although he later earned a general equivalency diploma) and moved to northern California.

He returned to performing, and auditioned for Shock G of the group Digital Underground. He was hired for the road crew and eventually performed and recorded with Digital Underground, appearing on the group's ''This Is an EP Release'' (Tommy Boy) and ''Sons of the P'' (Tommy Boy), which was nominated for a Grammy Award. In 1991, he started a solo recording career with the album ''2Pacalypse Now'' (Interscope), which sold half a million copies. It included two modest hits, ''Trapped'' and ''Brenda's Got a Baby,'' a song about an unwed teen-age mother's plight. Before the album was released, he also started a career as a movie actor, playing the violent, unpredictable Bishop in the Ernest Dickerson film ''Juice.''

In October 1991, Mr. Shakur said, police officers in Oakland, Calif., assaulted him because he was jaywalking; he filed a $10 million lawsuit. In the spring of 1992, a Texas state trooper was killed by a teen-ager who was listening to ''2Pacalypse Now,'' which includes songs about killing policemen. Vice President Dan Quayle demanded that the album be withdrawn; Interscope refused.

In 1993, Mr. Shakur played the male lead in John Singleton's film ''Poetic Justice,'' opposite Janet Jackson, and released ''Strictly 4 My N.I.G.G.A.Z.,'' which sold a million copies, mixing tales of violence with positive messages about women and the responsibility of fatherhood. It was followed in 1994 by ''Thug Life, Vol. 1,'' made by a group of rappers featuring Mr. Shakur. The group's hit single, ''Pour a Little Liquor,'' was an elegy for victims of gangster life; it was used in the soundtrack of ''Above the Rim,'' a movie in which Mr. Shakur had a supporting role.

In November 1993, Mr. Shakur was indicted on charges that he and some associates sodomized a 20-year-old woman in a Manhattan hotel suite. During the trial, he was shot twice as he entered a Manhattan recording studio and robbed of $40,000 worth of jewelry. He was sentenced to 1 1/2 to 4 1/2 years in prison for sexual assault. While in prison, he married his longtime girlfriend, Keisha Morris, but the marriage was annulled. In October 1995, pending appeal, he was released on $1.4 million bail, which was put up by his new recording label, Death Row Records.

His 1995 album, ''Me Against the World'' (Out Da Gutta/Interscope), apparently recorded before his prison term, was a more somber reflection on ghetto violence; it entered the Billboard album chart at No. 1, and sold two million copies. Upon his release, Mr. Shakur immediately began recording songs for ''All Eyez on Me'' (Death Row/Interscope), which has sold 2.5 million copies since its release this year. It was the first double album in hip-hop, and it also reached No. 1. The cautionary tone was gone; on the album, Mr. Shakur flaunted his success, reveling in fame and wealth.

''His latest album was his best-selling album, and one expects that he would have built on it from there,'' said Mr. Mayfield of Billboard.

Mr. Shakur had planned a tour this fall with other Death Row performers, including Snoop Doggy Dogg.

He is survived by his mother and a half-sister, Sekyiwah Shakur, who live in Decatur, Ga., and a half-brother, Maurice Harding.