Happening upon a briefcase lost in the park Tintin returns it to its owner [[AbsentMindedProfessor Professor Hector Alembick]], an expert in sigillography (the study of seals - the ones on letters rather than the ones with flippers). Professor Alembick is travelling to the Balkan kingdom of [[{{Ruritania}} Syldavia]] and offers Tintin a job as his assistant. Tintin declines but later finds himself under surveillance by sinister individuals who seem connected with that country. After more than one attempt on his life Tintin decides to accept Alembick's offer and accompany him to Syldavia and get to the bottom of things.

Tintin soon finds himself thrust into the middle of a ruthless conspiracy to overthrow King Muskar XII of Syldavia in the interests of their fascist neighbor Borduria. Faced with traitors at every turn, Tintin has to race against time to save the King's throne. If the stolen King Ottokar's Sceptre is not returned by St. Vladimir's Day, the King will have to abdicate and the Bordurians will invade...

''King Ottokar's Sceptre'' was written in 1938 and 1939, in the light of the threat of fascism; the Bordurian plot has parallels with the Anschluss (annexation of Austria by UsefulNotes/NaziGermany) and Syldavia's location is reminiscent of Albania (invaded by UsefulNotes/FascistItaly in 1939 a few months before the outbreak of UsefulNotes/WorldWarII). Both Syldavia and Borduria would play important roles in later adventures. The story also introduced the recurring characters of Bianca Castafiore and the villainous Colonel Boris Jorgen.

* AbsentMindedProfessor: Professor Alembick, due to constantly dropping his cigarettes.
* ANaziByAnyOtherName: The Bordurians - though they also have elements of other 1930s fascists. For instance, their front organization in Syldavia is called the Iron Guard, which in real life was the name of a Romanian fascist movement.
* ArtShift: For a few pages instead of comic panels we see a tourist brochure to quickly bring readers up to speed about Syldavia, its culture, its history and the fact that the king needs his sceptre to reign. In the process Hergé mimicks medieval European and Persian miniature painting for some of the illustrations.
* AsideGlance: Tintin actually winks to the reader on the last page.
* BlackShirt: Almost literally.
* BombThrowingAnarchists: Not actually present in the story, but Colonel Boris accuses Tintin of being one to discredit him in the king's eyes, reflecting the fears of anarchist terror in the early 20th century.
* CreatorCameo: In the redrawn colour version, Creator/{{Herge}} and his then assistant Edgar P. Jacobs (''ComicBook/BlakeAndMortimer'') can be spotted in military uniforms attending the royal reception at the palace.
* CreatorProvincialism: Arguably in that the royal palace of Syldavia is modelled after the one in Brussels. However, this is probably deliberate, as many critics see Muskar XII as a thinly-veiled expy of King Leopold III and Syldavia's situation as an expression of fears of what Nazi Germany might do to its little neighbor Belgium.
* DinosaurDoggieBone: Snowy steals a bone from a dinosaur skeleton at a museum.
* DoesThisRemindYouOfAnything: The [[TheGhost unseen]] leader of the conspiracy is named [[UsefulNotes/BenitoMussolini Müss]][[UsefulNotes/AdolfHitler tler]].
* EasyAmnesia: The Syldavian spy at Tintin's house.
* EvilChancellor: Colonel Boris, who is part of the conspiracy. The unnamed prime minister however, subverts this trope.
* [[spoiler: EvilTwin]]
* FunetikAksent: The Syldavians and Bordurians actually speak distorted versions of ''Marollien'', the dialect spoken by Flemish speakers in Brussels, slightly disguised by spelling it as if they were two Slavic languages. The Syldavian royal motto "Eih bennek eih blávek'' for instance roughly translates as "Here I am, here I'll stay".
* GeorgeLucasAlteredVersion: In the original black-and-white version the uniforms of the Syldavian royal guards looked a lot like British Beefeaters; in the reworked colour album they were reworked into something that actually looked like the kind of ceremonial uniforms worn in Balkan monarchies. Also, the Bordurian fighter airplane that Tintin steals was changed from a Heinkel He 112 (a cutting-edge prototype at the time the story was first written, but never mass-produced) to a Messerschmitt Bf 109.
* TheGoodKing: King Muskar XII is clearly devoted to his people, and is even willing to abdicate rather than try and keep power through bloodshed. [[spoiler: Fortunately Tintin manages to defeat the conspiracy and save his throne.]]
* GorgeousPeriodDress: The uniforms of the Syldavian royal guards.
* IAteWhat: Tintin's reaction when he's told the Syldavian meal he's eaten includes dog, and [[EatTheDog Snowy is missing]]. Snowy comes [[BigEater out of the restaurant's kitchen]] moments later.
* ImpliedDeathThreat: Tintin gets one in the form of a Syldavian proverb on his restaurant bill.
* ImprovisedParachute: Involving an actual parachute.
* LockedRoomMystery: How was the Sceptre stolen?
* MakeItLookLikeAnAccident: Tintin is almost "shot while trying to escape". He only escapes by throwing himself headlong down a steep slope.
* MeaningfulName: Averted with Professor Alembick, unlike most scientist Punny Names in Tintin--an alembic(k) is a piece of alchemical/chemistry apparatus, while Alembick is a Sigillographer.
** Actually played straighter than you'd think: in French, "alambiqué" means convoluted, which describes perfectly the scepter plot that involves [[spoiler: Alambick's twin brother impersonator]]
* OutOfCharacterMoment: When Tintin meets Professor Alembick at the start, he's constantly smoking. He doesn't smoke at all for the rest of the book, which Tintin notes. [[spoiler:This is a clue that he's been replaced by an impostor]]. It's the other way around in the animated version where he suddenly starts smoking.
* ParanoiaFuel: [[InvokedTrope It seems like]] Tintin can trust no one in Syldavia and at one point even begins to wonder if even Professor Alembick has been replaced by an impostor. [[spoiler: He has.]]
* {{Portmanteau}}: In the original version off-panel character Müsstler ('''Muss'''olini + Hi'''tler'''). It has been speculated that the name Syldavia was created from "Tran'''syl'''vania" and "Mol'''davia'''".
* PunnyName: General Stassanow is a pun on the Belgian milk brand ''Stassano''.
* TheQuisling / TheMole / DoubleAgent: A disturbing number of Syldavians are in Bordurian pay. This is a reaction to then-widespread fears (the term "fifth column" had just been coined during the Spanish Civil War).
* RedAlert: What the King essentially orders nationwide when Tintin warns him of Borduria's plans to invade.
* RevealingCoverUp: Tintin wasn't suspicious of anything until the Syldavian conspirators got suspicious of him. Had they just let him be, their plan would have succeeded.
* RightForTheWrongReasons: Thomson and Thompson correctly deduce that Alembick's camera contained stun gas which incapacitated the guards, but mistakenly think the sceptre got thrown out the window by hand. Tintin figures out that the camera also contains a projectile launcher [[EurekaMoment when he sees some toy cannons in a toyshop (comic)[=/=]sees some cannons outside (cartoon)]].
* RippedFromTheHeadlines: When this story appeared in syndication in 1939 the Second World War was already on its way. Fascist Italy and Nazi Germany had intervened in the Spanish Civil War and Germany occupied Austria and the Sudetenland in 1938 and would invade the remaining Czech territories and Poland in 1939. Thus the threat of Syldavia being occupied by Borduria in by a man named ''Müsstler'' had a very real context.
* RoyalsWhoActuallyDoSomething: King Muskar XII drives his own car and knows how to use a gun to protect himself.
* {{Ruritania}}: Syldavia and Borduria. Syldavia in particular is often ranked as one of Hergé's greatest achievements - an extremely detailed and well researched fictional nation with its own history, flag and language.
* ThirdActStupidity: After narrowly preventing the sceptre's thief from [[RunForTheBorder crossing the border to Borduria]], Tintin, having not eaten in two days, notices an apparent farm on the other side of the border and succumbs to the temptation of crossing it, still carrying the sceptre.
* VariableTerminalVelocity: Snowy falls slowly enough to get caught in the opening parachute deployed from Tintin's chair.
* YouKnowTooMuch: There are a number of attempts to kill Tintin once he starts meddling.