Adventurer's guild. They exist because its useful to have people that are experts in violence on standby, and no nation keeps a large standing army except when there is a war on, which is rare.

Its cheaper to allow these guilds to exist and tax them, and in exchange you get experienced, loyal mercenaries whenever you need them.

The Twelfth Hour

Spaceships move like seaships or aircraft depending on size. Yes, I am well familiar with how orbital mechanics works and how real spaceships move. However, it doesn't fit the aesthetic I'm going for, so I'm not using it, and am instead adding this bit of unrealism.

I will never stop making people ride animals that are not remotely rideable in a practical sense. Princess Mononoke unglued my brain with Big Wolves As Steeds. I'm sticking to it.

In seriousness the main character I currently have serving as Odd Cavalry is a bandit who rides essentially a smilodon bobcat- fictional big cat known in-setting as a Hill Tiger- and it IS a significant hurdle for her to overcome that cats are as supple and flexible as they are, so she rides in much more of a harness than a saddle, strapped to the cat's back rather than sitting astride it.

Frankly, I think that's a lot more fun than the wince-wink of 'haha yeah I know this is a Bad Trope' because this is art we're talking about, and while it's theoretically possible to create objectively bad art, it's way harder than anybody imagines it to be. I can go back and look at things I wrote, drew, dreamed up when I was ten and very much an amateur, and overwhelmingly they are, yes, rough and often derivative, but also? I think they have an incredible amount of spirit and energy to them.

Just because I'm no longer writing the world of Carousel doesn't mean that the base idea of "travel to a secret magical world by riding a merry go round whose animal seats are actually idols of Mythic Guardian Beasts that serve as gods" isn't an interesting concept you could tell a fantastic story about. The actual building blocks of the narrative were fine, they were just mortared together in an amateurish and flimsy way, and, that's a given, I was ten.

Use your kid brain to pick what's cool and fun and exciting, and then use your grownup brain to ask yourself the practical questions of 'how that works'. The visual of a lady riding a giant scary mountain cat is cool. People will like it. Will everybody? Nah, but part of what I want to do with my art is have fun and let other people have fun. A given amount of the Fantasy Genre, to me, is about making people point at things in excitement and go "wow, that's cool!"

Cool starships and ships shaped like naval vessels because with enough tech, who gives a shit about realism? If you can't engineer and weaponize blackholes, you have no business.

Selecting a Champion to fight in place of an army.

It's justified by virtue of the sheer cost of space warfare. Nobody wants to have this level of destruction going on.

Also, infantry engagements in general.

Due to legal ruling in the 2090s a WMD is defined as "a means of harm that operates indiscriminately".

An autonomous kill vehicle isn't a legal individual and therefore tantamount to pumping Zyklon B into the air supply

Airships with sails. I just think they a neat. They are technically spaceships but Treasure Planet did it beautifully.

I don't care if it's dumb. In every world I make, there is precedence for getting isekaid to there or out of there. Now, is it common knowledge? Not generally. But there is a precedent. This way, one day, I can eventually go to my own worlds because that's totally how it works, right?

The evil organization that’s “you fool I know all your plans and have control of the world.”

In my world, there exists the Black Oath. A collective of names throughout civilization that feed information, resources, blood, you name it to their leaders and creators, the Black Hearts. Some ten plus, less than twenty mercenaries in direct service to a god of reflection. As in, looking back on your chosen actions and the fallout of them. They personally take care of any job sent to them through the Oath’s connections, be it a marital dispute in a civilian home or a governmental depression. As long as they are paid for a desire of information and/or death, it will be learned and it will be done. They take no side, they serve no agenda, they cannot be caught or reasoned with. They are merely the divine gaps between what someone wants to, can, and will do, but refuse by some internal logic.

And boy do some of them love their jobs.

I WILL keep adding cowboy gunslingers to the deserts of my stereotypical fantasy worlds until moral improves.

Those who cannot see spells and revolvers coexisting are WEAK and will not survive the winter!

Shut up everyone I can't hear you over my dutch West India company dragons hanging out in Australia.

What if Europe had dragons so therefore the colonisers had dragons instead of gunpowder.

Flying saucers. I justify it in that's how the STL drive works. "Gravity polarizer" spinning around "quantum singularities" to create "pseudogravity" for the artificial gravity and propulsion in normal space. I justify it with quantum physics pseudoscientific gobbeldygook. It's complete bullshit!

https://preview.redd.it/t25j7ehd7h8g1.jpeg?width=800&format=pjpg&auto=webp&s=e6efa078c1343ac9a13575fb0762cd8bcb6cb737

Proud warrior race, especially in sci fi. Do I agree with Templin it wouldn't survive past the late middle ages? Yes. Do I use it anyway? Yes.

Justifications are mostly a caste system. The warriors are supported by many other castes, most of their culture is equally devoted to their caste (although I'm sure the lower castes love farming and mining and weaving with no chance of social mobility). But mostly I just acknowledge it's impractical and unstable and use that in the story

"All aliens are blue alien girls"

Well, you see, all the ones willing to do business and coexist alongside humanity are humanoid and evolved as such convergently. There are plenty of marine people and other such groups but most of them don't bother even leaving their planets. Of the four races that created the galactic conclave all are humanoid.

I don't know if it is, but incorporating references from other pieces of media into your own. I have several. I have made sure that they aren't just copies, though.

I'm seeing a couple of different versions of "trashy" being used here, but I guess based on how at least some people are using it...

I have several all female "species", two the result of magical experimentation, while the third species uses parthenogenesis to reproduce. All three are often viewed as attractive by humans, although perhaps in different ways (including Medusae, who are less the ugly monster of mythology and more borrow from modern "hotter" interpretations). I of course have no all male species. I also have a catfolk that are pretty much a rip-off of the classic anime catgirl/catboy type, because I like to include the classics and at this point if you consume any anime those folks are about as common as elves and dwarves, and I like the aesthetics.

To the OP's original point, unless it's done really poorly or offensively, I don't consider "Fantasy France but XYZ different" to be trashy. Like, some of the classic works of fantasy, modern and old, do the same thing. A lot of my world is basically imagining if historical events went different, how would things change.

I unfortunately don't read enough media to know what the trashy tropes are, what constitutes a trashy trope?

Kemonomimi catboys. I'll be called every name under the sun and won't give up the catboys. In-world I justify it (and the world in general) by human genetic engineering (one more trashy trope!) when they actually are there because I put my aesthetic preferences first. If that's catboys then let them be.

Dumb skimpy outfits. It's the future, people dress differently. And there are some ancient artifacts people can use instead of armor.

So I have a few, but one of the main ones is "classes." That's to say archer vs swordsman vs mage or whatever.

The explanation is a person's "saebis." You see, you need to use mana to use magic, but the body can only hold so much. Some people can hold more than others (and different medicines and such can help you increase yours), but ultimately the difference isn't all that great. Enter a saebis, a way of "refining" the mana within you. Essentially it gears the mana within you to more specific uses, limiting what you can use it for but in turn reducing the amount of mana you need to use for a given purpose. The more you "refine" it the less you need to use, until you're hyper-specialized in a specific field (say a "flame swordsman" by way of example) to the detriment of all other potential uses.

Now there are some caveats there. Strictly speaking your saebis alone wouldn't limit you to be a "flame swordsman" (until you reach the hyper-specific saebai), you could be a "flame warrior" who could also use spears and bows and so on. But for the majority of people, it's cheaper and easier to specialize with a specific weapon. Not simply because of the training (though it's not irrelevant), but the cost of the weapon itself. How much does a decent spear cost? A not inconsiderable amount. After all these aren't just a simple wooden shaft with a metal head attached to them, if so it wouldn't be terrible. But most metals are poor conductors of magic, and most woods aren't really great without special treatment. So you need a shaft that's either made of a very specific wood (expensive) or specially treated (also expensive), and a spearhead made of a special alloy (expensive) or specific metal (expensive). That will also go for things like bows and swords and so on. So you can see why having multiple types can prove prohibitively expensive.

Adventurer's Guild: Abundance of monsters, remote locations, appearance of dungeon kinda spread the standing army which allow the Guild to exist in the first place. Aside for that, the reliance on monster part for some industries allow these guilds to thrive.

Humanoid Mecha: Human's magic is more effective and efficient by significant margin in human shape. And bigger shape allow to carry larger mana containers and use larger scale magic without significant amount of mana exhaustion.

Handsign & yelling attack's name: By giving certain conditions and perform the technique according to these conditions, a technique's effectiveness will highly increase.

RPG's class: Learning the predetermined skill in a skill tree is literally meant using the skill's donor or "creator" through some memories shenanigans. A class is literally just a collection of skill memory that was grouped due to effectiveness of these skills working together and the purpose of the class.

Job system: You can change your class, by changing the rune. But not all Skill memory can be permanently engraved in your memory & skillset.

Big monster: Simply monster easily grow in mana heavy region.

Ruin: The war against monsters has actually been going on for centuries and had pushed back the Human Civilization Region up to more than half. These ruins are just cities that had been lost to it.

I love it when characters in stories have meaningful names, especially ones with a lot of layers to them. I feel like this can easily have the effect of making the story feel less real and the events less organic, though — which can certainly work for a more comedic story, but might feel a bit jarring with something that's supposed to be more grounded in tone or explore more serious themes.

I think actually exploring the implications of and questions the nominative determinism stuff brings to mind makes it feel a little less egregiously artificial (or at least I hope it does lol); so, in general, a lot of the stories I work on tend to have themes of fate, seeking patterns in / narrativizing coincidence, and what shapes a person into who they are.

The story I've been restraining myself the least in is heavily fairytale-inspired and generally surreal, so there's already a higher suspension of disbelief from the outset. For a (kind of) realistic fiction period piece thing I'm working on with a team, we're doing name symbolism from a "what the parents wanted their kids to be" lens rather than something actually reflective of the characters as they are.

Trashy? Idk if so. But I always have badass armored women in my settings. Justification may be thin.

In one world, I just say that female elves are the bigger and stronger gender.

In another, mages rule everything and magic is a great equalizer. Actually, this justifies a lot of my armored woman world building.

In another, vampirism is a hell of a drug. And powered armor is the norm regardless.

Doing absolutely nothing to change the economy, world politics or culture despite being 150 years in the future. I have no good excuse for this, I just don’t care about those aspects and this probably isn’t getting seriously published ever anyway, my standing justification for currency and linguistics is that they are “translated” for the convenience of the reader

A much more convoluted justification I came up with: I don’t have a real story, but the concept involves a time anomaly in geostationary orbit which threatens to break down causality through a naked singularity. The time anomaly already caused the theoretical protagonist to live near-identical simultaneous lives in 2038 and 2188, so I guess it could also be nudging the entire world in the direction of repeating events

characters that look bad and evil but are chill guys

like the god that punishes greedy people, or 90% of people that live in hell, or the members of a deep underground mining team, or the spiritual symbol of freedom

all of them look scary,have killed people before

but only out of necessity and circumstances (except for the first god, he just kill people if they are greedy)

and most of the time its one member or one incident that gives them the stereotype of being evil

Large scale splitting rivers on the map. Few reasons for justifying it:

1. The world is relatively young, only around 100,000 years old - and the courses of most rivers are only around 9000 years old.

2. The world was reshaped and "artificially" engineered by divine light beings 9000 years ago.

3. The terrain does not generally "slope" over large distances to collect waters. It has hills, mountains, noise, etc. but they average out to flat.

4. Large patches of thick rock exist underground that the course of a river can't easily erode through, forcing the river to split.

In my world there’s some regions that are just wild and ‘unclaimed’ In the real world people would fight over such expanses you could mine them, farm them or use it for something even just as a buffer against neighbours.

In my world The Minch is a terrible boogy land impossible to map properly constantly under change its land is damp there might be gold and ore under the mud but it’s not worth the effort and the local Minch folk would fight back making expanding into it difficult if not just pointless. So the three realms on its border just don’t bother with it. Each has aspirations wondering what riches lay within. But the insidious tribes impossible terrain and difficulty actually knowing where you are mean it’s just left empty and poorly mapped

Humans can breed with anything.

It's the dumbest way to make humans stand out but it's just funny and I put it in. In my world humans can indeed breed and create offspring with any species. However it's because of this that humanity was enslaved and used as breeding stock for the other races until they eventually rebelled and gained independence.

Bs element magic. Fire, water, air, ground + light and darkness. Adding thunder if I'm daring. I just love this simple principle. I don't even have to justify it, only explain the limits.