History VideoGame / OpusMagnum

* {{Revenge}}: House Van Tassen is taken down by House Colvan. Anataeus and Concordia plot to take down House Colvan in return.
* RulingFamilyMassacre: It is not stated outright, but strongly implied that Taros Colvan ordered the Van Tassen nobles executed ''after they have surrendered''. In that case, it makes Concordia and Clara's intense hatred for him quite justified.

Like ''VideoGame/SpaceChem''[='=]s 'fake chemistry', ''Opus Magnum'' takes its cues from 'real' ''al''chemy: Only [[FourElementEnsemble the classic elemental primes]], neutral salt, and a handful of metals[[note]]The seven metals of antiquity; mercury/quicksiver, lead, tin, iron, copper, silver and gold.[[/note]] are used to create every molecule you construct in the game. The game draws many ideas from one of Zach's previous games, ''VideoGame/TheCodexOfAlchemicalEngineering'', including all the component atoms save sulfur, and arms and glyphs to manipulate the atoms and molecules you'll be working with, now on a hexagonal working space instead of Codex's orthogonal board.

* NowDoItAgainBackwards: Two puzzles from "Production Alchemy" require a complex molecule be disassembled in one compartment, transferred to a second compartment one atom at a time, and then reassembled in the same configuration. One is a method for chemically distilling liquor while the other is an attempt to create aether through continuous refinement of a substance. Amusingly, both puzzle descriptions lampshade how worthless both processes are: the liquor manufacturer insists its disassembly then reassembly unlocks unique flavors though the book's author is visibly skeptical while the aether "creation" is noted to be a fool's errand only pursued by a handful of fringe scientists who still refuse to accept that quintessence is the true "fifth element".

* {{Foreshadowing}}: Playing Sigmar's Garden unlocks additional conversation where Concordia mentions that Van Tassen's previous alchemists used their role as a way to get into House politics, which holds true for most alchemists she's met. Much later in the game [[spoiler:Verrin Ravari, alchemist of House Colvan, is revealed to have been planning to usurp House Colvan, with the destruction of Van Tassen laying the groundwork]].

* NowDoItAgainBackwards: Two puzzles from "Production Alchemy" require a complex molecule be disassembled in one compartment, transferred to a second compartment one atom at a time, and then reassembled in the same configuration. One is a method for chemically distilling liquor while the other is an attempt to create aether through continous refinement of a substance.

* TheManBehindTheMan: [[spoiler:Verrin Ravari]] claims he was manipulated Taros into starting the war between the Houses.

* MotiveRant: Having found Anataeus, [[spoiler: Verrin Ravari, Head Alchemist of House Colvan]], reveals that the happenings of the game were his idea, and that his plan [[spoiler: was to take control of House Colvan, and then proceed to take over the other Houses (which he considered weak from decadence, with his alchemy talent. He even offers Anataeus [[WeCanRuleTogether the remains of House Van Tassen, in exchange for his help]]. However, as detailed above, [[DecoyGetaway Anateus and Concordia are long gone]] by the time Ravari tracks down their hideout]].
* MundaneUtility: In contrast to the real world where alchemy never achieved the transformation of lead into gold and even today it takes a hefty amount of equipment and a degree in nuclear physics, in-universe this is a well-known and straightforward process, to the point of being ''passe'', especially by the main character's standards. He takes the indignity of having to perform such a basic procedure (twice!) poorly.
* NowDoItAgainBackwards: One puzzle from "Production Alchemy" deals with an attempt to create aether through constant refinement of the same molecule. The player must create a system to disassemble a seven-piece source particle, pass it through a single-piece transport to another chamber, and reassemble it in the exact same design.

** The "Production Alchemy" forewords notes that the near-infinite workspace of the main story's alchemy engine is a modern convenience. The puzzles which follow are based on previous generations of the engine which had far more limited space.

* {{Steampunk}}: Much of the game's art direction and aesthetics are inspired by this, with artwork that depicts characters wearing elaborate outfits, intricately detailed interiors, and airships. The architecture of the Great Houses and major landmarks such as the university grounds dominate the landscape of the city, resembling cathedrals and industrial palaces that dwarf everything else. Even taking the map's emphasis of these locations as a BroadStrokes depiction they must tower over the surrounding buildings.

* CompletelyMissingThePoint: Anataeus tries to convince his patrons that a war cannot be won by assigning him to make ''hair gel.'' Captain Gelt insists that having Frederick Van Tassen show up with impeccable hair to raise a sword will inspire the troops enough to turn the tide of the war. It doesn't.

* BrutalBonusLevel: After the main campaign is completed, you get access to the "Production Alchemy" puzzles, which require creating solutions in a limited space and with some new mechanics. The "Journal of Alchemical Engineering" is similarly difficult.

* GameplayGrading: After completing a puzzle the cost of your machine, the number of instructions performed, and the number of cycles to complete are recorded. They are then marked on a histogram of how other players have done on the puzzle, giving you an idea of how you compare.

* GameplayAndStoryIntegration: During the post-puzzle conversation of "Very Dark Thread", Anateus mentions they've used up their last supplies of mercury/quicksilver to make the eponymous thread. Starting with the next chapter, he has to use the "Glyph of Purification" to turn metals into their higher forms without mercury.

* KissOfDeath: The Curious Lipstick.

* {{Magitek}}: The transmutation engine is an atomic manipulator with magical parts that do more traditional alchemy. Think the [=WALDOs=] in ''[=SpaceChem=]'' with alchemy thrown in.

* TheGreatestStoryNeverTold: Anataeus wistfully bemoans that the story of how he manufactured the Universal Solvent (one of the aspirations of classical alchemy) will never be known, but survival [[spoiler:and their revenge against House Colvan hinging on no evidence of his work remaining]] wins out over his desire for recognition.

* BrutalBonusLevel: After the main campaign is completed, you get access to the "Production Alchemy" puzzles, which require creating solutions in a limited space and with some new mechanics.

* {{Magitek}}: The transmutation engine is an atomic manipulator with magical parts that do more traditional alchemy. Think the [=WALDOs=] in ''[=SpaceChem=]'' with alchemy thrown in.