Doctor Who examples of stories with uncanny similarities to older ones.
- "The Gunfighters" has the same plot as "The Myth Makers", both by the same writer. A comedic historical story where the Doctor is mistaken for a historical figure (Zeus/Doc Holliday) and through a series of farcical events, people die.
- Not only is "The Moonbase" a Sequel Episode to "The Tenth Planet", it rehashes the same plot, just replace the South Pole with the Moon and the subplot involving the space capsule in danger with one about a mysterious illness.
- "Spearhead from Space" was based on a story that Robert Holmes wrote for the film Invasion, which featured an alien crashing in the woods near a rural hospital, where a medical examination reveals his alien nature. The hospital is later visited by other aliens, seeking a fugitive criminal. Some of the exact lines of dialogue used by human doctors to describe the physiology of the injured alien were re-used, which ended up creating the defining two-hearted feature of Time Lord anatomy in the process (while also giving viewers familiar with the one-hearted First Doctor something to scratch their heads over).
- "Day of the Daleks" was apparently a rush adaptation from The Outer Limits script "Soldier".
- Terry Nation rehashed "The Daleks" for "Planet of the Daleks". It contains some of the same plot devices, including: a group of Daleks in a city encountering the Thals on a ravaged planet; a deadly plague instead of a neutron bomb; someone using a Dalek shell as a disguise; the Doctor imprisoned in a cell and with paralysed legs (albeit in "The Daleks" it was Ian whose legs were paralysed); and the Daleks imprisoned in their city at the end of the story.
- For "Robot", Terrance Dicks drew on The Avengers episode "The Mauritius Penny", which he co-wrote with Malcolm Hulke, most notably for the scenes in which Sarah Jane infiltrates the meeting of the Scientific Reform Society.
- Both "The Android Invasion" and "The Brain of Morbius" — two consecutive serials! — feature a genius Mad Scientist who treats bodies like playthings and has a complex about creation and destruction, and a more sympathetic assistant who was rescued from a spaceship accident by the scientist and is missing a body part, who does a Heel–Face Turn upon discovering that the body part was actually accounted for all along. Part of this was because both scripts had to be heavily edited by Robert Holmes, who wrote most of the material between Styggron and Crayford in "The Android Invasion" to pad out the run time, and who adapted "The Brain of Morbius" to feature a mad scientist/The Igor pair to reduce the required budget; presumably he'd had this dynamic on the brain.
- The story "The Seeds of Doom" (by Robert Banks Stewart) was recycled from The Avengers' "Man-Eater of Surrey Green". (Stewart had written for The Avengers, but not that episode, which was by Philip Levene.) "The Seeds of Doom" feels wrong for a Doctor Who story in many ways, since it follows the Avengers formula. For example, the Fourth Doctor casually jumps on top of a bad guy and punches him out!
- The Doctor is coerced into leading his companions on a key Fetch Quest, which takes them to a wide variety of locales. Among the obstacles encountered are a Kangaroo Court trial at which one of them is sentenced to death. Upon completion of their mission, they must not turn the found items over to the one who demands them. Is this the First Doctor tracking down the Keys of Marinus, or the Fourth looking for the Key to Time?
- For his first script "The Visitation", Eric Saward recycles the premise and basic plot beats of Robert Holmes' "The Time Warrior".
- "Enlightenment" has a similar plot to that of "The War Games": both involve aliens abducting humans from various points in Earth history and using them for their own ends.
- "The King's Demons" has a similar plot to "The Time Meddler", in that they both involve Doctor trying to stop one of his own people trying to alter history.
- The Fifth Doctor story "Warriors of the Deep" bears striking similarities to the final First Doctor story, "The Tenth Planet". Both feature the Doctor and his companions accidentally arriving at an isolated military base and being mistaken for spies, and in both stories the Doctor's warnings go unheeded until the base is besieged by an alien threat. In both there is a section of the story where the alien invaders seize the bridge and the Doctor is forced by circumstances to stand by without interfering for a time.
- Writer Johnny Byrne drew inspiration from the Space: 1999 episode "Guardian of Piri", which he script-edited.
- For "The Two Doctors", Robert Holmes reused the idea of villains trying to steal the Doctor's genetic code from his unused script for "The Five Doctors". Originally it was the Cybermen, now it was the Sontarans.
- In many ways, Holmes' penultimate story, "The Mysterious Planet", is a bigger budget remake of his first story, "The Krotons".
- Holmes' final story, "The Ultimate Foe", repeats the plot of his earlier story "The Deadly Assassin": The Doctor has been brought to Gallifrey and is put on a sham trial for a crime he didn't commit, which turns out to be the result of a renegade Time Lord with a personal connection to him tampering with the seemingly infallible Matrix and conspiring with Gallifreyan politicians to achieve power and prolong his life (the Valeyard acting as a Composite Character of both Chancellor Goth and the Peter Pratt version of the Master). The Doctor chases him into the Matrix, where, despite being at a huge disadvantage, he defeats him in a battle of wits and walks away a free man, but not before the renegade escapes and sneaks off to cause more mayhem.
- For "Time and the Rani", Pip and Jane Baker drew upon their 1986 Find Your Fate book Race Against Time, in which the Rani tries to build a Time Destabiliser in order to reshape the universe to her design.
- "Silver Nemesis" received some complaints that it was the same basic plot as "Remembrance of the Daleks" (earlier in the very same season). Both concerned the Doctor arranging events so that he was ready to destroy an invasion of Earth by some of his deadliest enemies using an ancient piece of Time Lord technology (that the enemies themselves had hoped to gain control of). Both stories also feature themes of bigotry and racial purity, and a group of humans who naïvely try to ally themselves with the alien invaders.
- "Fear Her" itself is very similar to "The Idiot's Lantern" from the same season. Both feature an alien who imprisons people during a major televised event in London (the Queen's Coronation and the Olympic Games) and a child with an abusive father. In both, at the climax, one of the protagonists falls victim to the alien, and the other must rescue them before time runs out. "Fear Her" was written in a hurry to replace a Stephen Fry-penned script that ultimately went unproduced, which could explain the recycling process. It would then go on to be recycled twice:
- "Night Terrors": A child in an everyday contemporary Earth environment turns out to be an alien whose reality-warping powers cause his fears to threaten his family and neighbours. When did we see that before?
- "Flatline": The antagonists can turn two-dimensional things into three-dimensional ones and vice versa. The Doctor ends up trapped by them and can only assist his female companion from afar in protecting others and ensuring his return, whereupon he sends the antagonists back where they came from. The main difference is that the "Flatline" antagonists, the Boneless, are malicious rather than misguided-but-sympathetic.
- "Smith and Jones" gets its plot recycled for "The Eleventh Hour". Both involve an alien convict with shapeshifting powers escaping to Earth and a group of alien police threating to kill innocent people if they cannot find it in a certain amount of time. This requires the Doctor and his new companion to find it first. Additionally, the Doctor's sonic screwdriver is destroyed at one point and a hospital is a major setting.
- Chris Chibnall recycles "Planet of Evil in his first new series script, "42". Like Planet of Evil, it involves the crew of a spaceship mining a sentient body for a fuel source. The celestial body wants it back, and possesses people in order to sabotage the ship. Only difference? The Doctor is possessed too.
- "Victory of the Daleks" borrows big chunks of the lost serial "The Power of the Daleks", but with more of a knowing, Internal Homage/Whole-Plot Reference approach. The stuff that's borrowed — Daleks feigning servitude to humans, the Doctor protesting that they're pure evil and no-one believing him, a quirky scientist who discovered them promoting them to the leader of his people as a new development that can solve all of their problems, the Daleks doing it all as a plan to grow their ranks — is all aesthetic stuff, and the actual plot machinery itself is fairly different. For example, "Power" takes place on a human colony on another planet, "Victory" is set in WWII London.
- "The Curse of the Black Spot" (Eleventh Doctor) uses almost exactly the same Twist Ending as "The Empty Child"/The Doctor Dances" (Ninth Doctor), revealing that the Monster of the Week was actually just medical software for an abandoned alien ship, and that its actions were the result of it blindly following its programming and trying to heal injured humans without understanding human physiology. The plot even involves a young boy's relationship with a distant parent that he barely knows. It takes place in The Golden Age of Piracy instead of World War II, and the monster is a siren instead of a zombie, but the plots are otherwise exactly the same.
- The Minisodes "Meanwhile in the TARDIS 2" and "Clara and the TARDIS" are both virtually identical accounts of the Eleventh Doctor's companion getting the TARDIS to show them a slideshow of former companions (with the male ones conspicuously missing) and show comical disgust at the Doctor's perceived womanising, as well as his "typical male" interests in machines and women, with the implication that the TARDIS is doing it out of female jealousy. "Clara and the TARDIS" also swipes scenes from the Red Nose Day special where multiple Amys get stuck in a time loop and flirt with each other, when multiple Claras get stuck in a time loop and flirt with each other.
- "Deep Breath", the Twelfth Doctor's debut story:
- The basic plot is sort of a Darker and Edgier version of the Fourth Doctor's first story, "Robot", which Steven Moffat mentioned using as a reference — with the A and B-plots swapped. The Doctor regenerates and suddenly develops an absolutely crazy and seemingly uncaring personality that disconcerts his companion(s) and the people his previous self works with ("Robot" B-plot, "Deep Breath" A-plot, with Clara's discomfort central to the story) while a robot with an ambiguously humanlike personality and psychological complexes mirroring the Doctor's own is responsible for some bizarre murders ("Robot" A-plot, "Deep Breath" B-plot). The Doctor's defeat of it is rather ambiguous as a happy ending, but the companion agrees to give the new Doctor a chance to befriend her — after a bit of talking to from the Doctor. Several lines and setpieces from "Robot" were lifted into "Deep Breath" to indicate the similarities: Vastra quotes one of the Brigadier's lines apropos of nothing, and the Twelfth Doctor's white nightgown is similar to how the Fourth Doctor is dressed in the infirmary.
- The minisode playing before it in cinemas shows Strax giving a Field Report to the audience about all of the previous faces the Doctor has had, with funny descriptions of their personalities, to assuage an audience needing a reminder that the Eleventh Doctor was not always the Doctor — a format previously used for one of the "Strax's Field Report" online minisodes. The introduction is repeated almost word-for-word, although Jenny and Vastra interrupt it in the cinema version. Few of the jokes are recycled, though — Strax's opinions on the other Doctors (not to mention which gender he thinks they are) are completely different between both minisodes.
- "The Caretaker" is largely a retread of "The Lodger" - both stories are breather episodes in which the Doctor goes undercover - badly - as a regular human, in order to apprehend an alien threat. Indeed, both episodes take as their title the identity the Doctor assumes. The stories had the same writer.
- "Dark Water"/"Death in Heaven", the Series 8 finale, combines the central plots of two previous season finales: "Army of Ghosts"/"Doomsday" in Series 2 and "The Sound of Drums"/"Last of the Time Lords" in Series 3. In Series 2, beings that are assumed to be the souls of deceased humans turn out to be Cybermen planning an invasion of Earth via a parallel universe; Series 8 has deceased humans being tricked into letting their consciousnesses and remains become the basis for a Cyber-army. In both Series 3 and 8, a recurring background character is revealed to have been a regeneration of the Master all along, planning to wipe out humanity with an army of robotic minions — leading to a pivotal scene aboard an airborne UNIT base where "The President" holds court as Earth's representative. Replace ghosts with skeletons, "Mr. Saxon" with "Missy", the Toclafane with the Cybermen, Valiant with "Boat One", and the President of the United States with the President of Earth! All three stories also end with the Doctor and his current companion parting ways under unhappy circumstances, but that's par for the course for NewWho season finales; notably, all three companions are reunited with the Doctor sometime afterward.
- "Heaven Sent" draws upon the classic series serials "The Deadly Assassin", in which a companion-less Doctor is trapped in a nightmare world and pitted against an implacable, deadly foe for a lengthy stretch, and "Castrovalva" in that said world (the city of Castrovalva/a mysterious castle) is the creation of an enemy and capable of shifting and changing its form, leaving the Doctor to figure out a way to escape before he's destroyed. In addition, the villains in both stories turn out to be Time Lords. But much as "Deep Breath" focuses more on its characters and their emotional states than "Robot" did, "Heaven Sent" is at heart a tragic character study of the Doctor instead of a conventional adventure. The reason he is companion-less is not because he couldn't take her with him to where he is, but because she is dead, meaning his mood is much different than in "The Deadly Assassin". Save for one scene he's the only character who has dialogue, and the episode is only about him trying to survive and escape the isolated location — there's no villain for him to defeat, only a monster to run from, and he doesn't confront the party responsible for his torment until the next episode.
- Aside from those, there's an apparently heavy influence from Steven Moffat's favourite Sixth Doctor episode, Rob Shearman's "The Holy Terror", which also features the Doctor trapped in an Epiphanic Prison shaped like an immense castle with no outside, in which events eternally reset and recur. The only major differences being the Twelfth Doctor is alone, and he, not another character, is the prisoner.
- "The Lie of the Land" borrows a lot from past episodes. The Doctor and Bill recruit a group of soldiers to take down a group of aliens with religious connotations that also shoot lightning like in "The Wedding of River Song", the villain using a network of mind control devices to control and rule humanity — and the plan to turn it against them — plus the setup of the companion needing to save the Doctor while the villains have control of Earth first happened in the Series 3 finale, and the companion stopping the villains thanks to the memory of her deceased mother (with the fact that the memory is not real being important) comes from "The Rings of Akhaten".
- The Master's plan in season ten involves creating a Cyberman army. A black character who is relevant throughout the series is Killed Off for Real and then reborn as a Cyberman while the companion goes though Break the Cutie as a result. Now, are we talking about "Dark Water"/"Death in Heaven" or "World Enough and Time"/"The Doctor Falls"? The main differences are Clara's love interest is converted and her Break the Cutie is due to grief in "Dark Water", while it is the companion herself who is converted and being forced to take The Slow Path while separated from the Doctor and getting Cyber-converted is what breaks her in "World Enough and Time". Plus, there are two Masters running around in the latter, with one flipping sides. Thinking it through, some of this is intentional: after Saxon regenerates into Missy offscreen, she tries his plot again with what's left behind from it but with a more — to her way of thinking — positive end in mind than he did. She'll fail, and eventually make her way to this point only to die because she forced him to regenerate, bringing her story tragically full circle.
- Also, a common complaint about the denouement was that it meant that two of the Twelfth Doctor's companions had virtually the same final fate. Both Clara Oswald and Bill Potts end up staving off death by becoming immortal or close enough to it, leave with another immortalized woman to travel the universe for more adventures, and neither bid the Doctor a proper final goodbye due to him being amnesiac of them/apparently dead at the time, meaning he doesn't know until the end of his incarnation what actually became of them. It's even more similar for those who ship Clara and Ashildr/Me, as Bill and Heather are canonically lovers.
- "Arachnids in the UK", like "The Green Death", has mutated invertebrates caused by the illegal dumping of toxic waste into a mineshaft by a Corrupt Corporate Executive.
- "The Battle of Ranskoor Av Kolos" inolves an evil alien targeting planets and compressing them into small balls that they keep on display. This was the premise of "The Pirate Planet".
- "Resolution" is one to 2005's "Dalek". Both episodes reintroduce the Daleks to the series after a period of absence, by showing how menacing and dangerous a single pepperpot could be. They start with a single Dalek damaged and contained, but unintentionally allowed to restore itself by human technology. Both Daleks manipulate humans to further their escape, and kill large numbers of soldiers in their way. They interface with human information technology, demonstrate flight capabilities, and are eventually destroyed by fire.
- There are also similarities to Gareth Roberts' novella I am a Dalek, in which a deactivated Dalek is found in an archaeological dig, and a young woman falls under its influence as it restores itself.
