Adaptation Displacement: In America at least, hardly anyone has heard of the Musical/Stageshow. However it's pretty popular in the UK.
Alternative Character Interpretation: Depending on which fanfic you read, Dr. Frank N Furter is either A.) An abusive, psychotic, heartless jerk who only manipulates and hurts (both physically and emotionally) other people for his own personal amusement or B.) A misunderstood person who only acts the way he does due to some mysterious past tragedy.
Likewise, are Riff Raff & Magenta an evil brother/sister duo plotting Frank's downfall, or are they merely the victims of Frank's abuse and their actions are completely justified? Fanfics will vary greatly on the answer.
There are also plenty of fics where Columbia's personality ranges from bubbly and full of energy all the time, to always in tears and constantly depressed. Fan fic writers can't seem to make their minds up.
The only thing that could keep Hot Patootie - Bless My Soul from being a BLAM is the fact that the dinner scene calls back to it. With little or no warning, Meat Loaf rides out of a walk-in freezer on a motorcycle, sings a song, and gets murdered. That's about as BLAM-tastic as it can get.
Subverted with Eddie, since it ends up being pretty plot relevant.
In the original play, Eddie is mentioned by Columbia before Riff & Magenta (and the Phantoms) else tells them to keep quiet...Which foreshadows Eddie's inevitable appearance, musical number, and death. However, this foreshadowing (for some reason) was cut from the film causing Eddie's appearance and musical number to be totally out-of-nowhere. It's a a bizarre case of the character's scene being a BLAM, yet having the character being important to the plot.
Cult Classic: Typically cited by reviewers as the definitive example of a cult film.
Designated Hero: Brad and Janet, literally, in the opening credits. There's a reason that they're respectively called "Asshole" and "Slut" by riffers.
Do Not Do This Cool Thing: Kids, don't have lots of sex, or you might end up in a fabulous musical. It's ultimately left up to the audience if Brad and Janet embracing their desires has left them broken. (This is less ambiguous if one accepts Shock Treatment as canon, as they definitely start that film as broken, and it is only over the course of that film that they relearn how to be functional people.)
Many fans try to present Riff Raff and Magenta as being far more worthy of pity than they are in the film. Yes, the same Riff Raff and Magenta who kill Rocky, Frank, and Columbia out of pure spite.
Likewise, Frank gets the same treatment the same way. Um, since when are we supposed to feel sorry for the guy who tricked two innocent people into having sex with him, brutally murdered a guy from whom he removed half a brain (said half-of-brain was used to make Rocky, BTW) and then tricked said people he had sex with into eating the remains of the guy he murdered? The only aspect of Frank that anyone should feel sympathy towards is the fact that he's batshit insane. His final song, "I'm Going Home", is a very desperate attempt to get people to feel sorry for him. The fact that it doesn't work and he gets killed anyway speaks volumes about the character.
Ear Worm: Half of the songs featured fall under this trope, but perhaps most famously, Time Warp, which was ranked and voted 338 out of 2006 songs featured in the Triple M Essential 2006 Countdown.
Ensemble Darkhorse: Riff Raff and Columbia are neck-in-neck for fan favorite, next to Frank himself.
Evil Is Sexy: Frank is sexy. This can be attested to by every fan of this movie.
It's not just the movie version either- Rob Morton Fowler's portrayal of Frank in the recent European tour starts at sexy and goes straight into bishonen-beautiful.
Riff-Raff and Magenta both have large fan bases, and not without reason.
"LEEEEEET'S DO THE TIME WAAAAARP AGAAAAAAAAAAAAAAAAAAAIN!"
Its Cult Classic status and rabid fandom are also well-known.
The Zen Room.
"I see you shiver with antici...pation.
"I got pneumonia." note In an interview for the 40th anniversary on the Today Show, Susan Sarandon says this, and ever since the interview was broadcast, this has become a meme in the Rocky Horror community. For example, some people guessed it was the reason she didn't show up to the Royal Albert Hall 40th Anniversary screening.
Narm Charm: The movie is ridiculously camp and that's why people love it.
The one real offender is probably the corpse of Eddie under the dinner table, which is pretty obviously a mannequin. It could easily have been avoided if they just had Meat Loaf there in corpse make-up.
You can see the wires pulling Dr Scott's wheelchair up the stairs on his way to the zen room and when the castle blasts off at the end the real castle is visible through the smoke.
Too Soon: In regards to Audience Participation. Many older callbacks get updated references but otherwise remain the same. For example, when Riff-Raff shows Brad and Janet the skeleton near the start of the film, it's customary to shout out "SHOW US" and the name of whatever celebrity has most recently died. Bonus points if it's someone people really liked, especially if they had an early or especially tragic death.
The Woobie: Poor Rocky, who appears to be only slightly smarter than your average house pet, goes through a lot of grief in one night without having any idea why. Most fans sympathize very strongly with Columbia, who really gets treated like dirt.