These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Anvilicious: Spice is essential to the functioning of The Empire's economy, including its transport system. It's found in a desert that's home to a tribal society with unfamiliar customs with whom it's necessary to do business to get the stuff, whose religion is directly descended from Islam. Does This Remind You of Anything? Indeed, Word Of God says the analogy is intentional.
And in Sisterhood of Dune, the authors just can't hammer it in enough that Religious Fanaticism is Very Very Bad. All strongly religious characters in the book are members of a fanatical and dangerous anti-technology movement, and other characters frequently drop their other business to discuss just how irrational these people are.
Badass Decay: By the time of the first Dune book, the Sardaukar, though still considered formidable, can't hold a candle to their glory days (considered to be on the tenth Ginaz level and matching the abilities of a Bene Gesserit adept), which might explain their comparatively poor performance against the Fremen. Farad'n's Sardaukar avert this, however.
Complete Monster: Baron Harkonnen is a monstrous figure whose only concern is his own advancement and the glory of House Harkonnen.Initially lower than the Noble Atreides household, Harkonnen engineers its downfall, leading Duke Leto to a failed Heroic Sacrifice to try to kill the Baron. When his wife and children flee to the desert world of Dune, Harkonne assists in trying to crush the Rebellion in an essential genocide of the Fremen people. Revealing his two nephews, Brutish Rabban and intelligent, reserved Feyd-Rautha, Harkonnen plans to assign Rabban to brutalize the Fremen and then later have him removed by Feyd to cultivate the Fremen's goodwill with him. When Feyd attempts to assassinate Harkonnen, Harkonnen, in amusement, forces him to murder every woman in the pleasure quarter, chiding him "there will always be more women, Feyd." At one point, a character comments Feyd might have become a great hero- if only he'd been raised by someone who wasn't such a monster.
Designated Monkey: Paul refers to Irulan with pointed disdain, and seems to hold her partly responsible for their sham marriage. The author lets this view speak for itself, even though it is hard to square with the princess's actual depiction as a character, or with her future writings.
Fanon Discontinuity: Many fans vehemently refuse to acknowledge any Dune books not written by Frank Herbert. Herbert's son Brian and Kevin J. Anderson wrote two prequel series as well as a sequel series of two novels. Both differences in writing style, as well as serious inconsistencies with the original material, contribute to this reaction.
There aren't any names applied to characters or concepts in-universe, but many have cropped up to describe Fandom opinion. Those that only consider the books written by Frank Herbert refer to themselves as "Orthodox Herbertarians", while fans of the prequels and sequels by Brian Herbert and Kevin J. Anderson are called "preeqs". Then the preeqs retalliated by calling the original fandom "Talifans".
GodModeSue: Paul Atreides is famously this, but he's also one of the greatest subversions (or even deconstructions) of this trope in sci-fi literature. Paul has all the earmarks of what would be a complete Gary Stu: Son of an influential Duke, trained by the best swordsmen and tacticians in the galaxy, trained as a Mentat human computer, one of the few males trained in the "Weirding Way" of the Bene Gesserit sisterhood, prophetic powers, destined to become a galactic Messiah, and gaining leadership of the most Bad Ass Army in the Imperium. It turns out being a supposed Messiah to a certain people sucks, and he ends a far worse tyrant than those he replaced. He's also unable to prevent the death of the woman he loves. On the other hand, he eventually rebels against his past mistakes and failures and becomes an atoner who opposes the tyrannical regime created in his name.
Ho Yay: Teg and Patrin, to the point that Teg's daughter and several other Bene Gesserit comment on it.
The form Patrin's loyalty would take had been clear to Lucilla then. How could Teg have been so blind? Love! That long, trusting bond between the two men. Schwangyu would act swiftly and brutally. Patrin knew it. Teg had not examined his own certain knowledge.
Teg [thinking]: Patrin! Damn you, Patrin! You knew and I didn't! What will I do without you?
Ink Stain Adaptation: For the more sophisticated readers, the prequels and sequels by Kevin J. Anderson have kept them from the original series for fear it also caters to the Lowest Common Denominator. For fans of the new work... Well, they're in for a surprise if they try the originals.
"He who controls the (Spice/X) controls the universe!"
"I must not fear. Fear is the mind-killer!"
It is by coffee alone I set my mind in motion. It is by the beans of Java that my thoughts acquire speed, that my hands acquire shaking, the shaking becomes a warning. It is by coffee alone I set my mind in motion.
Ron the Death Eater: Not in fanfiction, but the prequel books make Count Fenring (and his BFF the Emperor) way more evil and cowardly than he was originally presented.
Sequelitis: Brian Herbert's and Kevin J Anderson's books. So far they have written six prequels, two sequels, and three midquels. Two more midquels are planned, as well as up to three more prequels. This will mean a grand total of 16 books compared to Frank's six. Milking the cash cow much?
Ugly Cute: Somewhat hunchbacked and with a scar on his jaw, Gurney is still a badass and friendly old mentor nonetheless.
Values Dissonance: None of the characters bat an eyelash at practices such as slavery, concubinage, gladiatorial fights, and institutionalized child abuse (specifically, the Bene Geserit gom jabbar test used on would-be initiates).
Fremen cultural practices, such as succession through killing, settling disputes through duels, and duel victors' inheritance of opponents' wives as spoils, contrast sharply to 21st century western values.
Leto II. Yes, seriously. Millenia of loneliness, of being the ultimate asshole by necessity, of having everyone hate his guts, all for the sake of preventing humanity's extinction. And did we mention that he never becomes free from basic human desires like finding love despite being a giant monster worm that has no penis? Yeah.
And as if that's not bad enough, Hwi dies.
'"Between the superhuman and the inhuman," he said, "I have had little space in which to be human. I thank you, gentle and lovely Hwi, for this little space."'
Princess Irulan gets a really rotten deal, while having done little or nothing to deserve it. She failed to become a Bene Gesserit and then was separated from her father (who she was clearly close to) and forced, because of politics, to accept a celibate marriage with a husband who resents her. This despite the fact that he was the one who demanded their wedding in the first place, to cement his rule. She spends the next decade or so living a lonely existence bereft of emotional comfort, knowing all the while that she's Imperial Consort only in name and she'll never be allowed to bear an Imperial Heir. Oh, and she's also somewhat in love with Paul herself, while it's very clear he considers Chani his real wife in everything but name. It hurts. Even when she drugs Chani with contraceptives you can understand why she does it, considering the immense pressure she's under from all sides and the sheer resentment she must feel. Paul puts it best: she's been used as a pawn her whole life, from her father to the Bene Gesserit to Paul himself.
This is worse in the miniseries, where Irulan has a greatly expanded role and becomes quite likable as she investigates her own father's conspiracy and does her part to bring it down. Then she gets the same ending from the book and we're still supposed to like it.
Yueh after he betrays Leto (the first), who he cared for and was grateful to, because the Harkonnen either had his wife captive or had already killed her, then taunted him with the fact that he would never be able to know if he gave her up for dead or not unless he broke his oath to Leto.
David Lynch Film / Syfy Miniseries
Angst? What Angst?: In the original book, Muad'Dib is fearful of the prospect of the inevitable jihads in his name, and takes displeasure when seeing one of the Fremen crying his name while killing a foe. In the 1984 adaptation, Muad'Dib practically embraces the jihads, and while he notices that his name has become a killing word thanks to the "weirding modules", he doesn't dwell on it at all. Not even for a second. Instead, he just acknowledges it and moves right along with his plan to ride a sandworm.
Broken Base: While most fans agree about the quality of the non-Frank Herbert novels (even if some still accept them), there is significant friction between fans of the David Lynch and Sci Fi Channel movie adaptations. Hell, evidence of it is available on these very pages ! The casting, acting, and costumes have been criticized by both sides. Criticisms of each side:
The Lynch version suffered from Executive Meddling, extensive voiceover exposition, some changes from the novel, and often an overly "80s feel".
The Sci Fi version of the first novel had the budget you'd expect from a cable miniseries and is more of an attempt at a TV drama than an outright movie epic. The issue is complicated by the Sci Fi Channel Children of Dune sequel (which includes the events of Dune Messiah), which is generally accepted as much higher quality, as well as being the only adaptation of the sequels on film. Since most actors reprised their roles, it's hard to "choose" the Lynch version of the original and still accept the sequel.
Nothing beats the Toto score from the 1984 film, especially the memorable theme, the Desert Theme and one of the best orchestral pop songs, "Take My Hand". The climax of the score ''Big Battle'' is also played in many times when the film is referenced in reviews.
Designated Villain: The Lynch film seems to make the story a bit more black and white than the original book, even going as far as to explicitly have Paul literally turn out to be The Chosen One. We're supposed to be cheering when he overthrows the evil emperor... except when you get down to it the Emperor didn't really do much that could be seen as "evil" unless one has read the book. To one who hasn't, he could come across as someone reluctantly pressed by another extremely powerful group into killing someone, who only actually leads an armed assault once Paul is doing things that could technically be considered terrorism.
Misaimed Marketing: Coloring and puzzle books for the David Lynch film Dune, which features graphic violence and murders, lots of folks in latex and tubes up their noses, a pus-faced psychopath who kills his male sex slaves by uncorking their hearts, and of course a gigantic fish mutant (Guild Navigator) with a vagina-like mouth. The coloring book made sure to provide lines on Baron Harkonnen's face so children can choose different colors for his facial pustules.
The extended cut of David Lynch's Dune film is made of footage that was cut before the final effects work was done so the Fremens' eyes will go from glowing blue to normal between scenes, and sometimes during the same scene.
The 2000 Sci Fi miniseries used painted backdrops with piles of sand in front of them for most of the desert scenes.
Squick: The 1984 depiction of Baron Harkonnen and his heirs. Heartplugs, grease showers, and a dramatization of the whole cat-milking thing...
Tear Jerker: Chani's death in the Children of Dune miniseries
Paul: There are problems in this universe for which there are no answers. Nothing. Nothing can be done.
What The Hell, Casting Agency?: The Lynch adaptation was fairly good with the casting, with nothing being blatantly out-of-place, but the 2000 miniseries cast a wide variety of nationalities, from French, Swedish, Italian, and other Caucasians with blatantly white skin and light hair for a people living in a desert and based on Arabs.
The Lynch film does have the mid-20s Kyle Mclachlan playing a 15 year old Paul; and Feyd played by Sting - the singer Sting.
For the role of Chani, Paul's love interest, the 2000 miniseries cast Barbora Kodetová, who is positively voluptuous. Chani is supposed to be a Fremen, and Fremen aren't supposed to have any body fat.
On the other hand, the 1984 adaptation has its own share of strange costume ideas. Bald bene gesserit who wear fishnets? Mentats with Einstein Hair and giant eyebrows? And while, at first glance, the stillsuits might not seem so bad, compare them to the stillsuits from the 2000 miniseries◊, which nearly covers the entire face. This makes sense, because the whole point of the stillsuits is to collect water that is evaporating from the skin or otherwise exhaled, so it's ideal to cover as much skin as possible and to cover the nose and mouth. Do you really think a tiny tube stuck up your nostrils◊ is a better alternative?