!!Tropes in the book
* AlternativeCharacterInterpretation: It's deliberately left ambiguous [[spoiler:if the Overmind is just in its manipulation and eventual assimilation of sentient races. The Overlords believe that it's a good thing, but they're basically the Overmind's slaves.]]
* EsotericHappyEnding: The Overlords think it's a happy ending, the idea that the children of [[spoiler:the final generation of humans AscendToAHigherPlaneOfExistence]], but it still involves [[spoiler:the extinction of humanity, and the "ascended" children are a bunch of feral psychic monsters that get assimilated into a HiveMind. Not to mention the Overmind has done this to possibly hundreds of sentient races, and only the Overlords say this is a good thing]]. If a different science fiction work kept the same basic plot and cast the aliens as villains, most people wouldn't question their action as villainous.
* HeartwarmingInHindsight: In the novel, South Africa is portrayed as a particularly troublesome nation, with the [[AmoralAfrikaner Apartheid regime]] being replaced by [[PersecutionFlip a Black Supremacist government]] that even the overlords have serious trouble fixing. While South Africa does still have problems with race relations, Apartheid ended in 1994, and Nelson Mandela and the ANC chose restorative justice rather than vengeance. South Africa had a much brighter future than Clarke predicted, with no aliens necessary.
* ValuesDissonance:
** The book was written when feminism was in its early stages, so there are a few jarringly sexist things with the men running the show and Jean only acclimating to New Athens when she learns to appreciate the kitchen.
** The offhanded way that the extinction of everything ''else'' on planet Earth is treated as a necessary sacrifice (despite there being plenty of ''lifeless'' planets in the solar system that could've provided the necessary energy) seems a lot harsher now than it probably did in the Fifties.

!!Tropes in the miniseries
* AlternativeCharacterInterpretation: Did the Overlords drive [[spoiler:Peretta]] to suicide with [[spoiler:images of her dead mother]], or was she simply deluded? Both possibilities seem valid, since the Overlords showed themselves willing to eliminate individuals who actively harm those they've deemed important.
* {{Anvilicious}}: Karellen [[spoiler: literally looking like the Devil, as in the archetypical BigRedDevil]], though that was probably the point the filmmakers were trying to make. The Overlords of the novel [[spoiler:did resemble classic Devils, but not blatantly so]].
* {{Narm}}: When Karellen finally makes his public appearance. While it's supposed to be a shocking revelation, it's hard not to laugh [[spoiler: at something that resembles Creator/TimCurry's [[Film/{{Legend 1985}} Lord of Darkness]].]]
* NightmareFuel: When the Overlords announce [[spoiler: there will be no more children born on Earth,]] there is a shot of a pregnant woman - whose stomach ''deflates'' as she screams in horror.
* RomanticPlotTumor: Ricky's love problem and Milo's girlfriend. They don't advance the plot of the Overlords in a way that couldn't be done with non-romance threads, and are mostly just there to appeal to the LowestCommonDenominator in what is a very hard science fiction story.
* TearJerker:
** [[spoiler: Ricky's death]].
** [[spoiler: Milo's return to Earth, and Earth's end. Pretty much everything after Milo's meeting with the Overmind.]]
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