Spearbreakers provides examples of the following tropes:
Abnormal Ammo: Mugs are suggested, and even dwarven children, to combat Spawn and Manamaids. These are suggested to serve as ammo for catapults.
Aborted Arc: Was originally intended as a Fan Sequel to Syrupleaf; however, this aspect was gradually dropped as the fort developed its own narrative, only showing in the form of occasional mentions of Parasol.
After the End: Technically, Spearbreakers takes place after Syrupleaf, which ended in a cataclysmic apocalypse where the world was turned into a giant block of obsidian.
Almost Kiss: One of these is shared by Vanya and Urist.
One overseer, Tomio, is basically an automoton, though he has another name for it.
Parasol employs mechs and mechsuits in its forces.
Anachronism Stew: To an extent, logical technological development is completely ignored, and the timewar companies have mechs, jetpacks and VTO Ls, but no fixed-wing aircraft. Spearbreakers also cobbles together multi-dimensional portals, time travel, and medieval warfare.
And I Must Scream: Softa, Ashsaber and Mad-Dok's consciousnesses remains trapped in their mind, unable to influence the body. Softa barely clings to her sanity by virtue of Fischer, Splint among others visiting her. Ashsaber is not known to Spearbreakers itself, though canon says he is a gibbering wreck. Mad-Dok is that one spawn that never screeches. Just looks. Creepy indeed.
Anti-Climax: Mitchewawa promised us he would invade hell during his turn. He didn't.
Mr Frog, though technically a good guy, would make a pretty wicked villain.
Talvi is also technically a good guy/girl, but she eventually becomes the antihero of several story arcs.
Anyone Can Die: In most Dwarf Fortresssuccession games, people embrace the fact that their characters can die at any moment. Due to Spearbreakers' canon style, the writers made sure the overseers avoided deaths whenever possible, but even the best efforts were often futile.
Ascended Extra: There are a few that fall into this category.
Joseph began as an Imaginary Friend of Talvi's, but gradually was revealed to become the leader of a powerful interdimensional company.
Vanya was originally a narrator for Talvi's adventures in the side stories, but turned into a main character that several overseers mentioned or made reference to in canon.
The italics portions in Vanya's journals turn into second person narration by Dr. Urist Jones.
Back from the Dead: This is actually an extremely rare occurrence, but it does happen. After Jack Magnus dies in combat, he gets resurrected again... and again... and again...
Back Story: Plenty of it, as found in Boatmurdered, Headshoots and Syrupleaf.
Badass Cape: In the canon, Mr Frog wears a cloak that makes him look more Bad Ass.
Baleful Polymorph: The new Spawn can inflict this on anyone they successfully land a bite on.
Balls of Steel: Tomio is impervious to kicks to the groin.
Beneath the Earth: Spearbreakers is contained practically completely belowground - even the entrances. This is because the horrors aboveground were deemed too dangerous to face.
Benevolent Boss: Though his speech was admittedly a bit difficult to understand, Sus definitely qualifies as this.
Beyond the Impossible: Technically speaking, as he had already gathered all the materials for his strange mood, The Master should not have gone insane. He did anyways.
Catch Phrase: There are more than one, though most of the characters don't have one.
Draignean's is "Armok's Infinite Beard"
Talvi's is "Fuggle", a made-up word she uses in the same manner as an expletive.
Colonel Badass: Colonel Fischer - it's scary how powerful the leader of the army became, racking up over 200 kills by Splint's second reign. Not only that, she was this Bad Assbefore she was sent to the danger room.
Conditioned To Accept Horror: This is every dwarf in Spearbreakers. Early on, Ashsaber and Softa transformed into Holistic Spawn, and were locked away in "isolation chambers", screaming their hatred for the living all hours of the day. These chambers were right across from the living area - the dwarves had to learn to sleep through it.
Hanslanda: "Oh god, everyone in the fort is heavily medicated and boozed up just to deal with backround noise. That's a bit hardcore."
Continuity Snarl: There are multiple contributing authours, and their individual plotlines often don't quite match up with each other.
Corpse Land: Due to the recurring Zombie Apocalypse, at one point there were literally thousands of bones strewn across the blood plains.
Creepy Cemetery: The Clover contains hundreds of unmarked graves piled together. Dwarves are forced to pass it on their way to the forges. Simon Tam's room is beneath it, too.
Crossdresser: Bombzero was actually a man. However, he's noted in the records as a woman because you'd never know he wasn't.
Deadly Training Area: Mr Frog put together an advanced-tech "combat simulation chamber" to rapidly hone the abilities of the militia. This was a subject of controversy among the overseers. Also averted, in Reudh's Spawn Containment Facility. Marksdwarves can engage Spawn in combat in complete safety. Doesn't stop civilians urinating themselves in terror whenever they pass by, though.
Deal with the Devil: As Hell is basically an extension of Spearbreakers, this happens often.
Mr Frog makes a deal and gets taken to Eris.
Mr Frog makes another deal to obtain an amnesiac for Talvi. Both of these deals are with Joseph.
Vanya agrees to work with Mr Frog as an assistant in exchange for Hans and Urist's lives.
Decapitation Required: The Holistic Spawn require either this, bisection, or the utter destruction of the heart, to be killed.
Depending on the Author: Everyone who writes about Colonel Fischer seems to portray her differently.
Demoted to Extra: The Spawn were originally intended to be the main threat to the fortress, but were soon superseded by the fort's own hospital and necromancers.
Doesn't Like Guns: Both Mr Frog and Vanya dislike guns, preferring to use other modes of weaponry.
Doomsday Device: A great number of these are discussed and/or initiated during the fortress's history.
Durable Death Trap: The traps that Dr. Urist Jones nearly falls victim to have been standing for over a thousand years.
Spearbreakers Laws of Interdimensional Teleportation
Personal Electronic Assistant
Spawn Powered Uninvitee Destroyer
Spawn Powered Invader Terminator
Combat And Training Simulator
Fucking Incredible Superdwarven Culler of Horrors and Ender of Reigns
General Failure: Draignean is the perfect example of this, being somewhat similar to Futurama's Zapp Brannigan.
Genetic Engineering Is the New Nuke: Nuclear warheads? Fixed-wing jets? No, none at all here. Instead, there's plenty of genetic gadgetry, mentalic mishaps and perilous propulsing.
Genre Shift: Many of the later story entries focus on an extended conflict between multiple interdimensional superpowers, a large shift away from DF's typical medieval fantasy setting.
Grenade Hot Potato: Hans bats away a grenade that a novice Ballpoint soldier threw.
Groin Attack: Vanya attempted this against Tomio, to try to escape him.
Heartbroken Badass: Splint's love, Stova, died after the initial Spawn attack. Splint redirects the pain towards the Spawn as hatred.
He Knows Too Much: Not really that much of a surprise, given Spearbreakers' conspiracy setting.
Mr Frog is exiled from Ballpoint pre-story because of what he knows.
Joseph and Mr Frog separately try to kill Vanya because of what she's seen.
Mr Frog tries to administer an amnesiac to Talvi to force her to forget what she's seen, and later obtains the assistance of Joseph for that purpose.
Heroic Sacrifice: Sus sacrificed his life on the spikebridge to save the last people who were coming in from outside. Interestingly, Sus II got a broken spine from that same bit of Malevolent Architecture.
Honor Before Reason: Sus II, after having been critically injured in a goblin attack, recovered, and was then critically injured again in a spike mishap. He still trains as a soldier despite having a BROKEN SPINE, making him a paraplegic. He lies on the ground attempting to train.
Mincer also refused treatment on his torn hand. His wife, Uvash, attempts to carry out orders despite missing her left foot.
I Call Her "Vera": Multiple examples of this, some in-story, some in-game.
Last of His Kind: Mr Frog is apparently the only survivor of his species in the Shared Universe, though not, perhaps, The Multiverse. He's described as being a dwarf-sized gnome, though he perhaps has an inch in height above the average dwarf.
Living Shadow: Rose's pet/companion, Halen. This causes a great deal of confusion as everyone seems to have a problem with it, treating its induction into canon as Serious Business.
Low Culture, High Tech: Eventually the Spearbreakers dwarves come across the timewar technology. Urist, Vanya, and Hans play around with it quite a bit.
MacGyvering: Mr Frog excels at this, creating bombs and weapons from spare lab equipment.
Mad Doctor: Kannan especially, but technically, any of the hospital staff could qualify as this.
Mr Frog is notorious for his experiments, which have little regard for morality. However, he's not precisely "mad"... At least, not most of the time.
Draconik Sankis claims this title with the creation of the Spawn of Fischer, as well as resurrecting Jack Magnus twice. Like Mr Frog, he's quite a bit saner than most of the other residents. It's ironic that in Spearbreakers, the mad scientists have more sense than everyone else.
Aussie Evil conducts unusual experiments with blood, greatly enjoying its taste and trying to "improve upon it". He's without a doubt the most "mad" of the three.
Malaproper: Talvi has a tendency to use phrases that don't make any sense at all.
Manchurian Agent: Vanya, the skulker, was what became known in the canon as a "Sleeper Agent" of Parasol, i.e. the person's agent side "sleeps" until "awakened", and they have no knowledge of that aspect of their lives.
Meaningful Echo: Vanya's story plays with this trope quite a bit.
Morality Kitchen Sink: In Spearbreakers, there is no Black and White Morality. No one is all bad, and no one is all good. The players like to show everything from every possible perspective. Sometimes even the Villains get displayed as heroes, and vice versa.
The whole of Spearbreakers. Unusual casualties and lost dwarves happen regularly, and sometimes to invaders. Spawn often get stuck in pits or on ledges.
Parasol doesn't care about the safety of its employees.
No Social Skills: Mr Frog can never understand people, and, on occasion, Terrahex finds Holistic Spawn easier to understand than his own species.
Oh Crap: When The Master came back to life, several players promptly shat their pants. A lot of dwarves did so in canon too.
"wait, where are you going? you are coming back, right? your not going to leave us with The Master, are you?"
—Aseaheru
Older Than They Look: Nobody ever guesses Mr Frog's true age until he reveals it. Who would've thought he's been around since Syrupleaf?
Pyrrhic Victory: The first Spawn siege in Reudh's reign resulted in NINE deaths, and two cripples. Additionally, Mad-Dok was infected with the Spawn Fever. The second Spawn siege in the same year resulted in two more, including Jack Magnus.
Mr Frog isn't quite 700, but he's well past three hundred.
Scylk is pretty old, too, especially by terrestrial standards.
Reforged into a Minion: Holistic Detective's Spawn can turn bitten dwarves into more of her toothy minions. This has happened to many over the nearly ten years; among them is Stova, Splint's lover and one of the founders of Spearbreakers, Softa and Ashsaber, both militia, and Mad-Dok, auxiliary militia. Softa, Ashsaber and Mad-Dok are cooped up in holding cells designed by Mr Frog.
Mugs. Mugs everywhere. And then more mugs inside those mugs. The spacetime continuum is screwed up just for the purpose of fitting more mugs within the same physical space as the other mugs.
Practically every overseer builds a new entrance (and sometimes two), while messing with or closing off one or more of the old ones.
People requesting a turn while expressing their doubts that the fortress will make it far enough for them to take it.
Fischer's gender is constantly being mistaken.
Did your dwarf die? Yes. Two turns later: No, they just got misplaced.
Dwarves (rightfully) assuming the worst when they're sent to the hospital.
Using Splint's War Giant Emus for leather.
Overseers have a habit of throwing a cavy down into one of the Spawn isolation chambers. Whether this is done for luck, or Just for Fun, nobody really cares.
Sealed Inside a Person-Shaped Can: Tomio is a technomancer. Inside his body is masses of integrated weaponry. It's not really a sealed entity, more an Astro Boy type affair.
Shield Bash: In the story, Hans has a tendency to use his shield rather than his weapon, as a Running Gag.
Shout Out: There are many, many of these. Here's a few:
The chief medical dwarf was originally Simon Tam, after the Firefly character. Later he got promoted to Mayor and removed from his position. Simon Tam isn't that great of a doctor.
"But it was a good once" - a reference to Doctor Who. This isn't the only Doctor Who reference, either.
"Dr. Urist Jones", named after the famous Indiana Jones series. His character is quite a bit different from Indiana's, however.
Colonel Fischer's name is occasionally misspelled as "Fisher".
Mr Frog insists on his name being spelled without the traditional period following "Mr".
LFTON's name is often spelled 'Lefton' to avoid headaches. Two of his alter egos, 0009 and Nine, have even more confusing, even unpronouncable names.
Summon Bigger Fish: The fortress's most frequent method of dealing with zombies is to wait for a squad of Spawn to show up and kill them instead.
Draignean: We're into autumn now, WE SURVIVED! (Granted we survived because Godzilla and Mothra arrived at the same time and decided to fight each other, not because of our military prowess)
After the first couple of years, Talvi became obsessed with Mr Frog, believing she was in love.
Lord Reudh has a creepy yet adorable crush on Rose, Splint's bodyguard. This is later determined to be an unusual aftereffect of Mr Frog's chemical concotions. After this, a single kiss from Vanya Carena is enough to make him fall in love with her, determined to follow her to the ends of the earth.
Strange Salute: During Draignean's reign, a punch to the face (the stronger the better) becomes the Spearbreakers salute.
That Was The Last Entry: This happens after Vanya's twenty-fifth journal entry. It's misleading because she's not actually dead.
The Alcoholic: Earlier in the story, Mr Frog was always calling for his Merlot.
This Way To Certain Death: Migrants coming to the fortress have to pass by the rotting corpses of other migrants that were left outside to die in the middle of sieges. Caravans have to pass the remains of caravans that didn't quite make it to the depot.
Time Travel: Loads of this everywhere, even though some people protested it. The timestream eventually becomes such a mess that it's a great big Timey Wimey Ball. Somehow, everything still makes sense.
Took a Level in Badass: Dauros, one of Fischer's squaddies, started off relatively strong, but is nearly as strong as Fischer herself. Dauros managed to KICK A SPAWN'S HAND CLEAN OFF.
Would Hit a Girl: A Ballpoint soldier takes a swipe at Vanya, and a little girl gets killed by Vanya herself.
Worst Aid: The "hospital" was one of the leading causes of death in the early years of Spearbreakers. Come for a stubbed toe, stay for the dehydration!
Yandere: There are at least two instances of this.
Talvi, with her obsession over Mr Frog.
The Master, who was incredibly possessive of Chestnut, his beloved wooden pike.