As expected from a movie about the "adult film" industry of the late 1970s and early '80s, "Boogie Nights" features a lot in the way of sexual content.

And while it's not quite as sensationalistic as it could be, the film isn't exactly tasteful — despite what some national reviews are saying.

But instead of just wallowing in nonstop nudity and graphic simulated sex, writer/director Paul Thomas Anderson treats most of the film's sex scenes almost dispassionately and in a humorous manner.

What's even more startling about this drama is that Anderson succeeds in the very difficult task of making us care about a close-knit band of adult-film stars — at least for the film's first hour.

However, in the extended second half, he delves into even more unsavory and ultimately unconvincing situations that seem to come straight out of "Pulp Fiction." Then he lets the whole thing bog down in a miasma of violence, gore and graphic drug use.

The film also deals with the repercussions of his characters' excessive lifestyles. But it never touches on some of the more important issues — such as AIDS and sexually transmitted diseases — much less the obvious moral implications that would have given the film added emotional depth.

Anderson's "everyman" protagonist, thrown into this seamy underside of sex and drugs, is Eddie Adams (Mark Wahlberg), a naive dishwasher looking to get away from his abusive, alcoholic mother.

Discovered by adult filmmaker Jack Horner (Burt Reynolds) for his "physical attributes," Eddie changes his name (to the more appropriate Dirk Diggler) and joins Horner's stable of young sex stars.

Under the tutelage of Jack and Amber Waves (Julianne Moore), Jack's most dependable actress, Dirk quickly becomes a superstar. He also finds a sense of belonging with this sort-of "family," which includes Buck Swope (Don Cheadle), "Rollergirl" (Heather Graham) and Dirk's new best bud, Reed Rothchild (John C. Reilly).

That success goes straight to Dirk's head and, following an on-set confrontation, Jack is forced to fire his now drug-addled, temperamental leading man. But rather than admit that they have an addiction problem, Dirk and Reed try to start new careers as rock stars, while Jack and the others gradually make a transition from adult movies to adult videos.

As mentioned, some scenes are handled humorously, which helps things tremendously, even when Anderson takes a few wrong turns. His proudest accomplishment is in the performances, especially stunning turns from Moore — the most sympathetic character of the bunch as Dirk's "mother" figure — Wahlberg and Reynolds.

But on top of some preposterous and near-fatal plotting errors, Anderson makes the mistake of creating too many characters (supporting stars Graham and Cheadle don't get enough to do, while William H. Macy is wasted for the sake of a punchline).

"Boogie Nights" is rated R (a very hard R) for violence, a few simulated sex scenes, some full male and female nudity (including the much-talked-about "money shot" of Wahlberg at the end), profanity, drug use, gore and a few vulgar jokes and references.