* AdaptationDisplacement: While the books are very popular, the TV series tends to be a little better known. A lot of details from the show - like Miss Bat and Miss Drill's AdaptationPersonalityChange, Maud's name being Moonshine, Ethel being a RichBitch - are mistaken as book canon. Jill Murphy even ran with it, notably expanding Drucilla's role in books written after the TV series. The TV movie is mostly forgotten, except for a few nostalgic fans.
* AlternateCharacterInterpretation:
** Mildred's status as the Worst Witch in the school is up for debate. On the one hand, she is quite bad at a few things. But on the other, she seems to be mainly bad in the school environment. The main problems the teachers have with her is that she's accident prone, occasionally lazy and quick to break the rules. Once she's got the proper theory down, she doesn't seem to have any problem casting magic in the field. She also notably gets over her fear of heights through consistent broomstick flying - suggesting she might be BrilliantButLazy and fully capable of getting high marks if she applies herself.
** There's Miss Hardbroom's attitude towards Mildred too. There's reason to believe she just has a vendetta against the girl - as there are a lot of incidents where she shows blatant favouritism to Ethel and is quick to punish Mildred without giving the latter the benefit of the doubt. One has to wonder how much of Mildred's ineptitude stems from HB's treatment of her. On the other hand, Miss Hardbroom is always happy whenever Mildred does well in class - and she'll always sincerely thank Mildred whenever she saves the day. So it might be that HB thinks Millie is BrilliantButLazy too - and her dislike could be that she thinks Mildred is wasting her potential.
** With regards to Ethel and Drucilla, how much does Ethel care for her? There are times when Ethel seems to view her as a servant rather than a friend. Other episodes show that she does seem to care for her to some extent. Given that Ethel has no other friends, and appears to be a bit of a DaddysGirl, it's possible she wants a friend but doesn't know how to behave towards one.
* BaseBreakingCharacter: Hobbes from ''Weirdsister College''. Some give him the DracoInLeatherPants treatment due to his FreudianExcuse. Others find that it doesn't justify his awful behaviour and think he's unnecessarily dickish.
* CounterpartComparison:
** Given the ''Literature/HarryPotter'' similarities, Ethel gets compared to both Draco Malfoy (for being TheRival who's also a RichBitch) and Hermione (for being an AcademicAlphaBitch). It's theorised by some fans that Ethel is what Hermione would be if she had never made friends with Harry and Ron.
** Even more blatantly, Miss Hardbroom gets compared to both Minerva [=McGonagall=] (for being the stern, no-nonsense Deputy Headmistress) and Severus Snape (for teaching Potions and for heavily disliking -- or at least having a complicated attitude towards -- the main character).
* EnsembleDarkhorse:
** Miss Bat is the most popular of the teachers with fans. It's quite surprising given that she made one appearance in the books. Likewise Drucilla was well received - enough for Jill Murphy to feature her more in books that were written after the TV series.
** For non-book characters, Charlie Blossom as well - presumably for the {{Shipping}} potential. One episode character Deirdre Swoop also got upgraded to regular in both spin-offs.
** Clarice is also rather popular for someone who only made a brief appearance in the books and was in a supporting role for most of the TV series.
* FanPreferredCouple: Mildred and Ben from ''Weirdsister College''.
* FridgeBrilliance:
** Ethel gives herself a "witch-over" in season 2 because she's embarrassed by her sister (explaining why she is played by Katy Allen). However in ''Weirdsister College'' she is played by Felicity Jones again. Now she's at college where her sister isn't there, she doesn't have to worry about being embarrassed by her so she removed the "witch-over". Likewise Deirdre Swoop doesn't recognise Ethel in the first episode because she had only seen her witch-over self.
** It's stated in the first episode that the right words in spells aren't as important as the right feelings. Episode three deals with Ethel being turned from a pig into a duck by Charlie getting the spell words wrong. The brilliance is that Charlie has not been educated in magic at all so he can't rely on "the right feeling" - so all he can go on are the words to the spell. Alternately he might have been concentrating on "turn Ethel back from a pig" but not concentrating enough on what to turn her ''into''.
** Closely related is Enid's spell for food in "Let Them Eat Cake". Like Charlie, the spell fails because of the last word. Both she and Charlie put emphasis on the last word in the incantation - resulting in the wrong effects. Charlie says Reduccio as "re-DUCK-io" so Ethel is turned into a duck. And Enid says "make it hasty" and gets them showered with hay. Also for Enid's spell - hay can be a snack for animals. Enid just wasn't being specific enough that she wanted food for herself.
** Why are spells in Latin when any incantation will do (coupled with the right feeling)? Because Cackles prides itself on tradition and Latin was what the upper classes wrote books in back in the days the spells were invented.
** Why doesn't 'Miss Cackle' notice the other three teachers spying on her class in "A Bolt From The Blue"? [[spoiler: Because Agatha can't see properly through Amelia's glasses]].
* HilariousInHindsight: Fairuza Balk playing the titular Worst Witch in the TV movie. She would go onto become a practising Wiccan in real life later - and would play an Ethel type in ''Film/TheCraft''.
* IronWoobie: Miss Drill if you think about it. She's one of the few non-witch members of staff (in the TV show anyway) and is constantly at odds with Miss Hardbroom. Although she experiences plenty of FantasticRacism, she just keeps on with her job and trying to do her best.
* LesYay:
** In ''The New Worst Witch'', Dyllis Mustardseed seems to be crushing pretty hard on Belladonna Bindweed. Too bad Belladonna hates her.
** The bickering between Miss Drill and Miss Bat in Season 2 could slip into this at times.
* {{Narm}}:
** Merlin trying to reseal the Dragon Lord back into the cave. He says "Back from whence you came" as if he couldn't care less.
** Miss Drill's evil persona as Hilary Hemlock. EvilIsHammy to the last degree.
** While Sybil is an effective Woobie, any time she actually has to cry on screen, it's painfully forced.
* OlderThanTheyThink: An isolated medieval castle containing a magic school, with a forest nearby? A protagonist who has no prior knowledge of the magical world? A rival who comes from a leading magical family? A hook-nosed Potions teacher who favours the rival and despises the protagonist? A kindly, grey-haired Head who befriends and helps the protagonist? Classes in Charms and broomstick riding? While both ''The Worst Witch'' and ''Harry Potter'' clearly have very similar elements, Jill Murphy's series predates the latter by 23 years, with the first book being published in 1974.
* PainfulRhyme: Tim Curry's big song features every conceivable word that rhymes with "Halloween," and many that aren't.
* ReplacementScrappy:
** Katy Allen for Felicity Jones as Ethel. Likewise Ted Blossom being an {{Expy}} of his brother Frank. Averted with Miss Crotchet, despite replacing the fan favourite Miss Bat.
** In ''Weirdsister College'' Cas Crowfeather gets a bit of hate for replacing Maud as Mildred's best friend.
** Caroline O'Neill replacing Kate Duchene as Miss Hardbroom in ''The New Worst Witch''.
* TheScrappy: Jadu has very few fans in comparison to the rest of the main cast - mainly due to her role as TheGenericGuy and her actress's wooden delivery.
* SpecialEffectsFailure:
** The music video made by Tim Curry aka the Grand Wizard. [[http://www.youtube.com/watch?v=PUhuPn8_d0Q Really, see for yourself.]]
** The flying effects on the TV show zig zag between this and being respectable enough for the era.
* TheyWastedAPerfectlyGoodCharacter: Ruby zigzags through this. While she does get a couple of more focus episodes as the series goes, she's still very much an obvious TokenMinority. Jadu meanwhile gets only one day in the limelight - which is the second last episode. In this case it's slightly justified by her actress just not being very good.
* UncertainAudience: The spin-off ''Weirdsister College''. It's DarkerAndEdgier, Georgina Sherrington claiming it was aimed at a slightly older crowd. But the acting and effects are still quite similar to the parent show, alienating a lot of potential older viewers. Meanwhile the show was a bit too dark and serious for the crowd who had grown up with ''The Worst Witch''.
* TheWoobie:
** Sybill Hallow. It's clear she has high standards to live up to, and she finds Cackle's terrifying at first. The fact that her sister is so embarrassed by her that she changes her appearance in the hopes no one will know they were related just adds to it. This line sums up Sybil perfectly.
--> "All I want is a sister. A real sister. Not a bossy-boots like Ethel."
** Mildred herself also has some aspects of this, since some of the staff seem to want her to fail. In the Season 1 finale when Miss Cackle appears to have gotten sick of her, Millie looks like she needs a hug. Ditto for the HalloweenEpisode where the whole school turns on her for her pratfall at the display.
** Dyllis Mustardseed in ''The New Worst Witch''.