Less Than Zero

Bret Easton Ellis' first novel. Less Than Zero was written when Ellis was 19 and was published in 1985. It was loosely adapted into a film in 1987.

Clay, the protagonist, is a bisexual college student back home in L.A. for the winter break. He comes from a pretty rich family and during the course of the novel, goes to a lot of parties, has a lot of one-night stands and does a lot of drugs. The story itself is a fairly frightening take on the amorality of the 1980s party scene.

Less Than Zero provides examples of the following tropes:

The Aggressive Drug Dealer: Julian's pimp and dealer.
Arc Words: Disappear Here.
Bi the Way: Clay.
Black and Gray Morality: While Clay does a lot of questionable and downright illegal stuff, he's nowhere near as bad as most of the people around him. To elaborate, the host of one of the many, many parties, buys a Snuff Film and screens it to all the partygoers while sporting an obvious erection. People stand around Clay's anorexic friend Muriel while she shoots up and take numerous pictures. A pair of drug dealers rape a little girl because they can't see any reason not to. Julian's pimp forces Clay to watch as Julian prostitutes himself to a client... It goes on and on.
Chained to a Bed: Clay's dealer has a twelve year old girl tied to a bed. His dealer also drugs her and uses her as a sex slave...
Character Overlap: Clay is also a minor character in The Rules of Attraction.
Crapsack World
Developing Doomed Characters: The point of the book, really.
Do Not Do This Cool Thing: In an interview celebrating the launching of his most recent book, Imperial Bedrooms, Bret Easton Ellis recounted how many fans of his work would come up to him and say "You're the guy who wrote Less Than Zero, that's the book that made me want to live in L.A.!"
The Eighties: Bret Easton Ellis' writing style generally incorporates a lot of pop culture, and this novel is no exception. Every paragraph just screams Eighties! Eighties! Eighties!!! from the parachute pants to the Ataris.
It Got Worse: Boy howdy. The book starts off somewhat pessimistically already, with Clay estranged from all the people around him, especially his sorta-girlfriend and best friend. And it just keeps going downhill.
No Name Given: Most characters (including Clay) are only known by their first names.
Screw the Rules, I Have Money: Many of the characters.
Sex Slave: A twelve year old girl.
Sick and Wrong: Clay's feelings about the Snuff Film and the twelve year old girl.
Snuff Film: Clay sees one being shown off at a party.
Unnamed Parent: Clay's parents are not named (neither are his two sisters).
Wild Teen Party
Your Cheating Heart: Neither Clay nor Blair have been faithful to the other during the school year.