Actor Allusion: Several Real Life porn performers had cameos. Nina Hartley appeared in several scenes as Little Bill's faithless wife. Veronica Hart is the judge at Amber Waves' custody hearing. More recent porn star Lil' Cinderella (credited as Amber Hunter) and Lexi Leigh have bit parts. Summer Cummings and Skye Blue share a Jacuzzi.
In a non-porn related example, Reed Rothchild shows off his magic skills to Kurt, who seems less than impressed. Kurt is played by Ricky Jay, a professional magician.
Cultural Rebel: Buck Swope, Don Cheadle's character, is a fan of country/western music, to the point that he wears cowboy hats and shirts with fringes (the whole Roy Rogers getup). Remember, he's played by Don Cheadle
Dirty Old Man: Colonel James. This point is driven home rather well when we see him in prison.
Disposable Sex Worker: The film is centred around sex workers, and the story explores them as three dimensional characters. However, while the story itself doesn't view sex workers as disposable an in-universe example has some suggestions about the porn industry as a whole could (can?) display a tendency towards this mindset; a girl, heavily implied to be both underage and either a sex worker herself or one of the Colonel's regular girlfriends, suffers a bad reaction to some bad drugs she's given during the early party scene, and while the guy who gave her the drugs freaks out, everyone else seems to view the fact that she's on the floor bleeding copiously as a minor inconvenience at most. She's last seen being carried away from the party as if she were trash to be disposed of.
Doing It for the Art: What Horner wants to do… or at least get people to stay in their seats after they've finished what they came for.
Domestic Abuse: A deleted subplot featured one of the porn stars, Becky, get out of the industry through marriage only for her husband to turn out to be a violently insecure man who would beat her. It was removed after the director felt that seeing all of the characters have horrible lives would have been too depressing.
Do Not Call Me Paul: After Eddie Adams takes the stage name of "Dirk Diggler" he insists that everyone call him that all the time.
Dumb Is Good: Almost all of Jack Horner's cast members exude sweetness and amiable natures. But none of them are the sharpest tools in the box. Especially not the bumbling, loveable oaf that is Reed Rothchild.
Drugs Are Bad: Especially if you have to give handjobs and get the crap kicked out of you to feed your habit.
Even Evil Has Standards: 'Evil' might be a bit strong, but while Jack Horner has little problem with the Colonel's obvious penchant for teenage girls who are clearly somewhere below the statutory age-of-consent limit, he is utterly disgusted and breaks with him completely upon discovering that the Colonel's tastes extend to pre-pubescent children.
Gut Punch: The movie is rather light-hearted and comedic for the first half, until the 1979-1980 New Year's Party scene where Amber introduces Dirk to cocaine, and Little Bill finally snaps and shoots his philandering wife, her lover and himself dead. From this point on, things get a lot darker.
Hookers and Blow: It's a story set in the porn industry covering the years 1977 to 1984. What did you expect? Sunshine and lollipops?
Horrible Hollywood: Played with. In a larger context, the porn industry is clearly this, being corrupt, exploitative and more than a bit shady (several of the producers are implied to have mob ties and definitely have rather unpleasant perversions). But when focusing on the main characters, while they are a bit dim, spoiled and incestuous, they clearly love each other as something like a family.
Mood Dissonance: The Drug Heist scene is a masterclass in Mood Dissonance, managing to be unbearably tense, terrifying, surreal and hilarious all at the same time.
No Celebrities Were Harmed: Dirk Diggler is clearly based upon John Holmes, from his prodigious member, to the botched drug heist that was an allusion to the Wonderland murders. Dirk even mentions Holmes at one point.
Similarly, Amber Waves' custodial problems were inspired by those that Veronica Hart went through. Hart even has a cameo as the judge presiding over Amber's case.
Oh Crap: The look on Rollergirl's face when, after kneeling to give Eddie Adams a blow job, she unzips his fly and sees what she has to deal with.
"You're Brandy, right?"
The Oner: The opening shot of the movie, and the next-to-last shot, forming Book Ends. Other long takes in the movie include the pool party scene and the end-of-the-70s New Year's party.
Porn Names: Dirk's original name was Eddie Adams. There's also Amber Waves (her real name is Maggie).
Inverted when Buck opens his stereo store called "Buck's Super Cool Stereo Store" and Maurice opens the "Rodriques Brothers Night Club". Both have very unclever names.
Remake Cameo: Michael Stein, who appears as the stereo store customer, played Dirk Diggler in The Dirk Diggler Story, P.T. Anderson's 1988 short film that was expanded into this movie (also, Robert Ridgely played Jack Horner in the short).
Team Mom: Amber takes many of the younger stars in Jack's employ under her wing and mothers them, in what is all but outright stated to be a substitute for her own custodial battles over and Missing Mom nature towards her own son. Takes on a slightly weird edge when it comes to Dirk, in that she appears to view herself as a mother-figure to him while simultaneously kind of falling in love with him at the same time.
Technology Marches On: Horner has a distaste for using videotape to film. He dislikes that video limits the quality of the image, as well as the fact that it opens the market up to any amateur that can stick a cassette in a camera, cheapening the whole industry.
Truth in Television: Due to all the prejudice they face, most porn stars only have friends in the business, and many of them can't even talk to their families anymore. Note that this is still true as of right now.