History FanFic / TheArithmancer

* NarrativeProfanityFilter: The fanfic makes liberal use of this, with many instances of characters cursing without descriptions of what they said. For example, in ''Lady Archimedes'' Chapter 61:
-->Hermione responded [to Umbridge catching her in the Ministry with her Polyjuice worn off] with curses, and not all of the spell variety.

* FriendToAllLivingThings: Hermione, though she makes an exception for [[YourSoulIsMine Dementors]].

* TimTaylorTechnology: Wizards believe that Dementors are immune to heat and fire. Hermione takes the view that "if fire didn't destroy it, you haven't used a fire hot enough," and builds a ritual around a solar furnace.

* UnusualPopCultureName: It doesn't ''actually'' happen, but George suggests to Ron in Chapter 18 of ''Annals'' that he should name his firstborn [[Film/ThePrincessBride Inigo Montoya Weasley]] if it's a boy.

* WizardDuel: Several throughout the series, and Hermione spends a lot of time refining her dueling technique and devising strategy. The final battle in particular devolves into one, while Hermione is laboring under a curse that forces her to fight alone. It is appropriately epic, and collapses the Astronomy Tower. [[spoiler:It is not with Voldemort, who was killed with ritual magic, but with a grief-maddened Bellatrix.]]

** The Third Task takes the form of [[spoiler:a tesseract maze]], which is mathematically regular, but hard to observe and far enough outside normal experience to mess with viewers' heads. Professor Vector thinks that Hermione could have made something worse.

* TimTaylorTechnology: Wizards believe that Dementors are immune to heat and fire. Hermione takes the view that "if fire didn't destroy it, you haven't used a fire hot enough", and builds a ritual around a solar furnace.

* CutHisHeartOutWithASpoon: Hermione's dire threat that gets the bullies off of Luna's back is… if they keep it up, she'll sic the Weasley twins on them.

--> '''Professor Vector:''' Miss Granger, as a scholar I very rarely say this, but you should not ask questions you do not want to know the answers to.

* CutHisHeartOutWithASpoon: Hermione's dire threat that gets the bullies off of Luna's back is...if they keep it up, she'll sic the Weasley twins on them.

* ZergRush: The triskelia of the Deplorable Word [[spoiler:are just a millimetre across, their individual attacks are like pinpricks, but since they [[GreyGoo consume all available material to self-replicate]], there are enough of them to [[DeathOfAThousandCuts gradually flay Bellatrix Lestrange alive]], starting with her hands and then her tongue to inhibit her spellcasting, then her Achilles tendons to stop her from running, and eventually eating all her organs.]]

* NailsOnABlackboard: One of Hermione's efficiency-oriented jinxes for low-powered casters produces a cone of dissonant sounds similar to this.

* PersonalityPowers: Hermione considers inventing a [[TheToothHurts Tooth-Drilling Hex]] for Harry to use in the Triwizard Tournament, but eventually decides to save it for herself as the daughter of two dentists.

** Later in the book, Professor Babbling teaches the ''Bliviklet'' spell to her third-year class to link runes together in Chapter 53, explaining its practical application for simple and temporary defensive and monitoring systems. This comes in handy four chapters later, when [[spoiler:Ron uses the spell to alert him and the rest of the group the moment werewolf-Lupin breaks out of the Shrieking Shack]].

'''Hermione:''' Just mention the words, [[spoiler:[[FinalSolution 'Mudblood Relocation Camp']]]]. Trust me, Molly, there will be then. Every muggle-born will understand ''that''.

** Basilisk kills with a stare? Use sunglasses with lenses of a certain color designed to filter out the yellow of its eyes. Although "mundane" is selling what they do a little short -- while the initial method of wearing sunglasses works, Hermione ''invents a spell on the fly to figure out the precise wavelength of light needed to block it out''. And better? With them, she's able to look the Basilisk in the eye and only feel like she's got a migraine, rather than getting knocked out, paralyzed, or killed.

* RefugeInAudacity: After Umbridge passes an Educational Decree banning teachers from teaching outside of their schedule or curriculum, Hermione points out that classes that aren't accredited by the Ministry don't require a teaching certificate, allowing her to continue her studies with Professor Vector. [[SubvertedTrope But when Umbridge finds out, she bans that too.]]

* SuperWeapon: Hermione designs one as, essentially, a side project while figuring out how to remove a Horcrux from Harry. [[GreyGoo It involves runecraft, transmutation, and duplication charms.]] It couldn't destroy the world... unless you started it in the right place. She is appropriately horrified at what she created, and puts the most important parts of the work under Fidelius.

* InstantBirthJustAddLabor: {{Downplayed|Trope}}. [[spoiler:Fleur]] was in labour for approximately three hours for her firstborn--not quite unrealistically short, but still much shorter than the average human, though it can ''possibly'' be justified that AWizardDidIt.

* VoiceOfTheResistance: In ''Lady Archimedes'', there are two--''Radio Free Britain'' (of which "Potterwatch" is a segment) on the Wizarding Wireless and the ''Liberation'' newsletter, [[spoiler:the latter succeeding from ''The Quibbler'' after a Death Eater attack on the Lovegood residence]].