Magic Feather: Pretty much everyone creates something that initially seems to give them magical powers. These are revealed to all be just focuses for their nascent abilities later.
Magic Kiss: This is a SBURB game mechanic. If a player dies (and if they have an intact dreamself), they can be revived if another player kisses their corpse within an unspecified time limit. If time runs out, the wounds propagate to the dreamself, killing them as well.
Magic Realism: There is an element of this in the way that no-one seems particularly surprised when Sburb allows you to manipulate other people's houses. Other fantastical elements of the world (particularly the gamelike ones) go unmentioned and unexplained. On the other hand, the existence of magic per se is realistically controversial.
Magikarp Power: Some aspects and classes are this. So far it's known that the Page class and the Hope and Breath aspect all are weak initially before becoming very potent. This makes Jake, the Page of Hope, an extraordinary example.
In Flarp, the Boy-Skylark class is described as this.
Medium Blending: The comic frequently uses animated GIFs, and there are occasional Flash animations and games.
Mega Manning: Enemies wielding weapons seem to drop the STRIFE SPECIBUS for that weapon. Though to date this has only happened a few times, as the only weapons any of the enemies have been seen wielding are ones stolen from John. This works for slain players as well.
The Merch: There's a lot of available merchandise from the comic, most notably everyone's clothing.
Vriska's and Tavros' dead bodies are thrown into Jane's game sprite, yanking their souls out of the afterlife and fusing them together as "Tavrisprite". Their personalities are so irreconcilable that the sprite explodes (sending the two souls back to the afterlife) mere moments later.
Eridan and Sollux were successfully fused into an Erisolsprite (which spends most of his time flipping people off at random), and Equiusprite is fused with Dirk's sentient AI auto-responder to create Arquiusprite. Feferi and Nepeta were also fused into a Fefetasprite, which had a peaceful life for six months but doesn't last long once Erisolsprite and Arquiusprite start arguing over her.
Mermaid Problem: Sprites have a similar anatomy to mermaids, leading John to ponder the, er, logistics of a sprite/human romance. He stops just short of asking his own sister how exactly she and her sprite ex-boyfriend got their mack on. Meanwhile, the fandom has come up with some creative solutions.
Mickey Mousing: Inverted: Andrew selects a piece of music from the artists and animates to its beats and any Leitmotifs present. This is taken to its logical extreme in the Descend sequence, which matches every single leitmotif in the song with an appropriate piece of action.
Minion with an F in Evil: The Imps. Easily cowed early on by things like threatening the pogo ride with shaving cream, by the Act 6 Intermissions they're just chilling with John and Jade, watching movies.
Mirror Universe: In some respects, the Post-Scratch Kids reflect aspects of the Pre-Scratch Kids they correspond to
John for a long time had his green slime ghost symbol and blue text, but his Breath sigil ultimately replaced his green symbol. Jane has blue text and a blue PS sprite as her symbol, but her Life sigil (which is an altered version of the Breath sigil) is green. Likewise they have some inverted tastes; John likes Gushers but hates cake but Jane feels the opposite. John was also the last member of his session to awaken his dreamself, but Jane was the first to have awoken, disregarding Dirk since he was already awake. Both are the leaders of their parties because of their "optimism through stalwart skepticism" and for considering themselves everyone's friend, not their leader.
Jake fights lusii routinely to survive, as opposed to Jade whose fights with Bec were playful at worst. Also, Jade was awake on Prospit for years, but Jake's dreamself was killed by Courtyard Droll and some peanuts before he even awoke at all. Both have a robot with whom they share the island, but Jade's dreambot is benign and completely passive, whereas Jake's brobot can move actively on its own, and both protects Jake from lusii and ambushes Jake for strifes on a regular basis.
Roxy enjoys gaming, hard science like genetics or physics, and writing lighthearted fiction, whereas Rose is one of the least game inclined of the kids, writes darker fiction, and tends to stick with psychology. Roxy is also completely blatant and guileless with her near-constant flirtation, as opposed to Rose, who layers her relatively subdued flirtation with heavy snark. As for their Sburb titles, both are seemingly passive classes, but Roxy and Rose's elements are almost polar opposites, and Roxy wholeheartedly embraces her powers, unlike Rose who went so far Off the Rails that she disrupted her Myth Arc.
Dave is associated with crows and favors absurd irony, while Dirk is associated with gulls and favors unsettling irony. Both are artists, with their interests in webcomics, specimen preservation, and photography (and movies), or with puppetry, pornography, and robotics, reflecting this. Dave had a mild phobia of Cal whereas Dirk thinks he's awesome, which is part of why when both awakened on Derse before the game, Dirk ran with it while Dave shut it out. Both have duplicates running around, but Dave is cool with Davesprite whereas Dirk bickers with his AR. Dave's Myth Arc is about overcoming his own self-loathing and being proud of his individuality whereas Dirk's revolves around his incredibly fractured sense of self, and trying to find who he even is.
Mission Control: A server player is this to their client player, essentially. Some classes like Seers naturally are this to their teammates.
The Exiles are an even better example, since they literally sit behind a giant glowing display terminal giving the kids instructions.
Money for Nothing: Zigzagged example. Boondollars start off as seemingly useless, then have a purpose revealed, then end up useless again as Dave earns so much money that their purpose is rendered irrelevant. On a more comical note, certainitemsofvery low quality can actually cost negative artifact grist to make. And here we learn that post-Scratch Dave massproduced them and got rich because they also are of a low enough quality to cost negative money to produce.
Monochrome Casting: The cast is aracial. They're white in the sense of a coloring book, and the reader can extrapolate any race onto them.
This is Hussie's stated intent, but most readers may find that for the human kids, their eye and hair colors serve to limit the reasonable possibilities somewhat (though see "Mukokuseki", down just a bit). Dave's "white" hair and red irises do suggest he may be albino, so he could technically be of any race. (Rose, his ecto-sister, also has "white" hair.)
Morality Pet: The troll concept of "moirails": particularly unstable trolls naturally gravitate towards nicer trolls that can keep their worst behaviour in check: examples include Equius and Nepeta, Eridan and Feferi, Vriska and Kanaya, and rather surprisingly, Gamzee and Karkat. Can be awkward if one member of the moirallegiance would rather it was matespritship (e.g. Eridan, Kanaya)
More Hero Than Thou: Rose and Dave trying to decide who will be the one to sacrifice themselves blowing up the Tumor to destroy the Green Sun. Ultimately subverted on a number of levels: both of them end up going on the "suicide mission", it ends up not being a suicide mission because they die on their Derse quest beds and reach God Tier, and the Tumor's explosion creates the Green Sunrather than destroying it.
Munchkin: The trolls. In their session, they pretty much only cared about gaining levels and skills, and killing all the monsters, while ignoring side quests and game lore. This is ultimately deconstructed when they get to the end of the game, since failing to create the Genesis Frog led to the creation of Bec Noir, who prevented them from winning the game.
Musical Spoiler: The background audio for "[S] Jade: Wake up" is "Let the Squiddles Sleep", which is on the Squiddles Soundtrack released well before the flash was. So a number of readers could tell just from the music that things were about to go horribly, horriblywrong...for Jade at least. For Feferi it's basically meeting the in-laws.
Used in a different sense with Umbral Ultimatum, the music for [S] Jade: Enter, the first few keys of it are played at the very end of [S] Descend, one act prior.
To those in the know, the second intermission's music instilled instant feelings of dreadnote The music comes from an album realised earlier before based around the Felt. The title of the track? English.
Mukokuseki: All human characters in the traditional racial sense, also extending to every character in the comic in terms of physical characteristics in general. Hussie has explicitly stated that every character is meant to be physically ambiguous in every way, stating that their physical characteristics are effectively up to the reader to interpret as their personal headcanon. The big exception is Hussie himself:
Note that I am caucasian, and I draw myself orange. I donít see no orange kids there! Canít really pin them down as definitively white, though this is likely the widespread presumption. They are canonically a-racial, and elude concrete bodily proportions through diversity of stylistic representation. You decide what they are! The thing you decide is right.
He's also stated that one reference to Bro being white was a mistake that he put in before he'd firmly established the character or his role in the story as Dave's father, so the intention was not to give implications of Dave or Rose's ethnicity through that line, to say nothing of commenting on Dirk.
Mummies at the Dinner Table: Grandpa (Pre-Scratch) and John Crocker (post-Scratch) are still presiding over their households as stuffed trophies. Jake is deeply envious.
GT: God jane is so lucky every day in her household must be like weekend at bernies! What a riot it must be im so jealous.
A few more are revealed in this formspring question. Namely, a lot of Equius is based on his Humanimals comic. Dave's puppets are based on some muppet comics he made on the MSPA forum. The wizard fics in Rose's house are based on his own wizard fic satire from years ago.
Necessary Fail: Any event which deviates from the Alpha Timeline creates a doomed offshoot timeline. Many events in the Alpha Timeline are, from the perspective of the characters, astounding failures, but must happen due to the nature of time in Homestuck.
In addition, doomed timelines can exert influence on the Alpha Timeline. This influence is in fact necessary for the Alpha Timeline to exist. So the failure to create a Necessary Fail is itself a Necessary Fail. This dialogue from Karkat seems to suggest that preserving the Alpha Timeline can be a Guide Dang It:
New Game+: The Post-Scratch Human Session ends up as this by virtue of breaking Sburb in two.
Nice Job Fixing It, Villain: Vriska and Tavros try to map the Furthest Ring to find a treasure that can supposedly kill Lord English. The only problem is that the furthest ring doesn't conform to the laws of physics, and is essentially a great black void, so trying to map it is completely impossible. However, English has been smashing his way through the furthest ring and dream bubbles, literally cracking the fabric of space time, thus making landmarks for Vriska and Tavros' maps!
No Fourth Wall: At the end of Act 5, the kids literally escaped a collapsing universe/reality by riding a spaceship through the fourth wall, into the the meta-level one plane removed from the actual story itself, co-existing with the author for a span of 3 feet, and then crashing through another fourth wall into another universe/retelling of their story. It's almost like a cyclical loop of how many meta levels removed from the story Hussie can try to get at this rate.
In Act 6 Intermission 4, Caliborn discovers a tower that appears to be transmitting the words of the narrator, and begins talking to it. Then he begins beating it with a crowbar, which results in the website being knocked into pieces.
In-universe example: In Roxy's fanfic wizardy herbert, the characters know they're in a story but are forced to do what the plot demands of them, and they complain about it all the while.
No Pronunciation Guide: Trolls. Averted, for their first names, at least. Hussie gave pronunciations on his old Formspring account, though he says that he doesn't care if other people pronounce them differently.
"When in doubt, be sure to pronounce everything in the least affected manner possible, from an American perspective. note CAR-cat, tuh-REH-zee, GAM-zee, TA-vros (rhymes with HAVE and GROSS), neh-PEH-tuh, eh-QUEE-us, eh-RI-dan (combine names Erin - n + Dan), uh-RAD-ia, fuh-FERRY, SAW-lux, VRISS-kuh, kuh-NIGH-uh"
Incidentally, in several cases, the fans who originally suggested the names have specified pronunciations based on the actual etymology - and often times they're completely different (Terezi, for instance, is, according to the original suggestion, pronounced tuh-REE-see. Really.)
Non-Combat EXP: Players can gain experience from solving puzzles or fulfilling elements of their quest. They can also cheat the system as well; if they fully awaken their abilities due to some circumstance, like John's Die or Fly manifestation of the Breeze, they automatically reach the top of their Echeladder.
Non-Mammal Mammaries: Despite the fact that Troll reproduction and life cycle has more seemingly in common with insects than primates, including a very insectoid larval stage, female trolls have breasts. Andrew has confirmed this is mostly so readers can identify with them.
Arquiusprite later starts to explain that female trolls' breasts do have some important biological function, but Dirk tells him to shut up because he thinks the topic's gross.
GC:1T W4S WH3N 1 GOT CLOS3 3NOUGH TO SM3LL 1T UND3R YOUR SK1N PL34S3 K4RK4T, DO NOT PR3T3ND TH4T YOU FORGOT 4BOUT OUR L1TTL3 MOM3NT CG: WHOA CG: YOU MEAN CG: DURING CG: FUCK.
Given Andrew's propensity for skipping large tracts of time, a great deal of the unexplored adventures have become Noodle Incidents. Though the frequent flashbacks mean that sometimes what seems at first to be a Noodle Incident will be depicted or explained later.
Karkat's grand speech, suggesting that they troll the kids. It's referenced repeatedly, and the other trolls mock him relentlessly for it throughout Hivebent's logs, but we never actually see it.
Noodle People: Noticeable whenever the kids are drawn as opposed to appearing as sprites. As seen here. The adults and the exiles don't have this though.
The Noseless: Virtually every single character (with the exception of John's Dad, who interestingly enough has nothing but). This is one of the few tropes Hussie has invoked (almost entirely) without lampshading.
After the post-AlterniaBound Art Shift, when a panel is in a more detailed style the characters are sometimes drawn with noses.
Not Now, Kiddo: Averted, John states his suspicion that there are monsters in his house to Dave, who is Genre Savvy enough to believe him.
TG: skepticism is the crutch of cinematic troglodytes TG: like hey mom dad theres a dinosaur or a ghost or whatever in my room. "yeah right junior go back to bed" TG: fuck you mom and dad how many times are we going to watch this trope unfold it wasnt goddamn funny the first time i saw it TG: just once id like to see dad crap his pants when a kid says theres a vampire in his closet TG: "OH SHIT EVERYONE IN THE MINIVAN" TG: be fuckin dad of the year right there
Nothing Is Scarier: Doc Scratch's message to Karkat is a simple warning: "Don't turn your back on the body." Of course, this occurs just after Eridan has killed Feferi, so Karkat looks away from the monitor and at Feferi's corpse... Only to find that nothing has changed.
Much later in the story: "John Egbert has gone missing." Not even the nigh-omnipresent narrative knows where John is after Jade attacked him.
Now Do It Again Backwards: Parodied on this page. One person is in a panic because he accidentally sat on his hat and apparently ruined it (...look, this is Homestuck; we shouldn't have to say it makes sense in context). The others suggest repairing it by "unsitting" on it, and one suggests turning it upside-down then sitting on it again. Thankfully, one person steps in to be the voice of reason.
Numerological Motif: The number two and duality in general. It's. Freaking. Everywhere. Prospit and Derse, Sollux and all his duality attributes, the trolls' and kids' multiverse, Pre-scratch and Post-scratch sessions, the bifurcation of Act 5... you get the idea.
Ocean Punk: Roxy and Dirk hail from 2422 AD, where the Condesce has melted the polar ice caps.
Official Cosplay Gear: If you want your very own official reproduction of one of the kids' or beta trolls' shirts, you can buy one from TopatoCo (beta trolls and beta kids) or What Pumpkin (alpha kids). What Pumpkin also sells copies of Aranea's Sufferer necklace and Terezi's scalemates.
Ominous Visual Glitch: Dave Strider, author of the deliberately awful in-universe comic Sweet Bro and Hella Jeff, finds a way to manifest objects from SBAHJ in real life, complete with jpeg artifacts. Disc 2 of Homestuck itself gets a nasty scratch, resulting in visual glitches reminiscent of an unreadable DVD. This leads to Doc Scratch taking over the narration while he fixes the disc. This happens again when Homestuck part 3 shows up as a game cartridge and gets clogged with "special fairydust". Entire planets get covered by visual glitches, scenes get skipped over because they're "unplayable" (and the protagonists don't remember anything that happened in these unplayable parts), and text glitches prevent some characters from understanding each other.
Omnicidal Maniac: Bec Noir after the death of (the original iteration of) Jade. He was already pretty stab-happy before, but this made him go on a rampage with the goal of destroying the universe and any other universe he could get his hands on.
Once More with Clarity: The scene at the end of Act 5.1, where the trolls are about to claim their prize, is revisited during [S] Jade: Enter, when the nature of the threat that prevented them from doing so is finally revealed.
Another example: one scene from the the End of Act 3 flash revisits a detail from the End of Act 2 flash, revealing that WV's ship was the cork of a giant wine bottle.
In [S] Jane: Enter, many of the buildings and scenery first seen in [S] Act 6 are revisited, showing how they change after a Time Skip. It then reveals that some of the images in [S] Act 6 - the ones involving the interior of Dirk and Roxy's houses - were actually from after the Time Skip, showing that Dirk and Roxy were living in the future all along.
One Character, Multiple Lives: One of the features of SBURB is that players have an additional body, their dream self, who begins the game in a tower on Prospit or Derse. Once the player awakens their dream self (usually via a personal epiphany or extreme shock) their consciousness will shift between both bodies: when you sleep in one, you immediately wake up in the other. There are a few variations on this setup such as Dirk Strider, who's fully awake in both bodies, simultaneously.
One-Gender Race: Played with. The trolls' reproductive cycle simply involves the mixing of two individuals' genetic material in a bucket, then dumping the resulting slurry into the womb of the Mother Grub to be amalgamated with countless other couples' DNA. This means that reproductive couples need not be of the opposite gender (see Everyone Is Bi). So, theoretically, all trolls could very well have the exact same reproductive organs. However, they still have genders and physical sexes, which according to Word of God are simply vestigial.
GC: MUCH 4S 1T P41NS M3 TO 4DM1T 1T, YOUR FRUITY OR4NG3 F4IRY SU1T SM3LLS... D3L1C1OUS.
Onion Tears: Dave, stewing in a cauldron of boiling water and surrounded by hungry crocodiles, blames the tears running down his face on the sliced onions the crocs assail him with. Terezi thinks he's just lying.
Online Alias: All the main protagonists have "chumhandles" that they use in their in-universe instant messenger clients. All of them reflect the user's interests or personality, or foreshadow their role in the series.
Only Six Faces: By default, every troll and kid has the same body and facial structure. Going further, the beta kids have the exact same face as their alpha counterpart (though with Jade and John's counterparts switched due to their genders, and Dave and Dirk with different sunglasses).
Only the Author Can Save Them Now: Deliberately invoked when Hussie personally rescues the Handmaid from Doc Scratch and Spades Slick from the destruction of the universe (though ultimately subverted with the Handmaid, as she ends up falling into Lord English's hands soon after.
Orwellian Retcon: A few panels have been redrawned usually when there's an error. A big one would have to be when John puts his arm into a white SBURB symbol, causing it to appear in various events during the story; the existing panels were re-drawn, implying that this was also a Cosmic Retcon in-universe.
Our Angels Are Different: For one they have no faces, and resemble snakes. They seemingly are associated with Heroes of Hope and are seemingly evil. Angels have also been said to serve Paradox Space. Eridan ended up attacking the angels that appeared on his land for most of his game, but ended up being nurtured by them to become more evil.
Jack Noir and PM also evoke a lot of angelic motifs.
Cherubs don't display particularly angelic characteristics as juveniles; they live up to their name better as adults, when they possess wings and the general characteristics of either angels or demonic figures, depending on which personality dominates.
It's revealed that the Angels are indeed connected to the power of Hope, as Jake's awakening to his Page of Hope is creating them in the Hopesplosion.
Our Werewolves Are Different: Though Jade's default Dogtier form falls under Little Bit Beastly, the Condesce's influence turns her skin black, gives her sprite widened eyes, and intensifies her bestial senses and behaviors so that she's occasionally called a werewolf.