A lot of people who write fantasy started the same way: with a map drawn on the last page of a school exercise book. A continent shaped like a hand, a mountain range made of zigzag peaks, a river that wasn't quite sure where it was going, and a castle in one corner with a name that sounded important. That map got lost in some house move, but the world didn't. It's still there, years later, waiting for someone to tell it.
If that's you, you have an advantage and a problem. The advantage is that you've lived in that world for a long time and know it better than anyone. The problem is exactly the same thing: you know it so well that it's easy to want to tell all of it, and a fantasy novel doesn't sink from a lack of imagination. It sinks from too much world and not enough story.
Fantasy also has some of the most loyal readers of any genre. They read long books, they read whole series, they draw their favourite authors' maps and argue for years about how the magic works in a universe that doesn't exist. That passion is a gift, but it's also a demand: they notice every contradiction. This guide explains how to build the world without letting it eat the novel, how to design magic that doesn't solve everything like, well, magic, how to create characters who matter more than the scenery, how to stay consistent across hundreds of pages, how to lean on AI without your world sounding like everyone else's, and how to publish the book on Amazon KDP.
Quick summary: A fantasy novel works when the world serves the story and not the other way round. There are four keys: a human conflict that would matter even without magic; a world the reader only sees as much of as they need, even if you know far more; magic with rules, limits and a price that gets paid; and total consistency in names, distances, customs and laws throughout the book. The usual length is 80,000 to 120,000 words, a little less for young adult and cozy fantasy. The most common mistake isn't a lack of ideas but stopping the story to explain the world. On KDP you can include your map inside the book, it pays to pick the subgenre carefully in your categories, and you have to disclose AI-generated content.
The whole journey, in seven steps
If you'd rather see the map before the details (and in fantasy a map is always welcome), here it is. Each step is covered further down.
- Choose the subgenre and the scale of the story: whether you're saving a kingdom, a neighbourhood or a single life.
- Write the central conflict in two sentences without using a single invented word.
- Build only the world the story walks through, and keep the rest in separate notes so it doesn't leak into the text.
- Design the magic with three questions: what it can do, what it can't do and what it costs.
- Create the characters from what they want and what the world stops them from getting.
- Write the draft alongside a world bible where you record every name, rule and fact that appears.
- Check consistency, get the book in front of readers and publish it on Amazon KDP.
What kind of fantasy are you writing?
"Fantasy" is a very big word. It covers a war between empires with dragons, and it covers a magical bookshop on a side street in Bristol where the worst thing that happens is a book refusing to be sold. Both are fantasy, but they aren't read by the same people or with the same expectations.
| Subgenre | What it promises | Usual scale | Usual length |
|---|---|---|---|
| Epic or high fantasy | A complete secondary world, conflicts that decide the fate of entire peoples | Large: kingdoms, wars, prophecies | 100,000 to 150,000 words |
| Heroic fantasy or sword and sorcery | Adventure, action and heroes on a human scale | Medium: one quest, one group | 70,000 to 100,000 words |
| Dark fantasy (grimdark) | Grey morality, violence and a cruel world with no clean heroes | Variable | 90,000 to 130,000 words |
| Urban fantasy | Magic hidden in a real, present-day city | Medium: one city, one threat | 70,000 to 90,000 words |
| Romantic fantasy (romantasy) | A relationship that weighs as much as the adventure | Variable | 90,000 to 120,000 words |
| Cozy fantasy | A kind world, small conflicts and characters who look after each other | Small: a village, a business | 60,000 to 90,000 words |
| Young adult fantasy | Protagonists aged 13 to 18 discovering who they are | Variable | 60,000 to 90,000 words |
| Historical or mythological fantasy | A real period or mythology with magic creeping in | Variable | 80,000 to 110,000 words |
The figures are a guide, but they're useful for something specific: if your first epic fantasy is heading for 250,000 words, you haven't simply written a lot. There are probably two books in there, or one book and half a book of explanations.
The other big decision is scale. Before inventing continents, ask yourself what's at stake. "The dark king is going to conquer the world" is an enormous scale and, oddly, not very moving, because the reader doesn't know the world yet. "If Nerea doesn't find the cure before the thaw, her little brother won't see the spring" is a tiny scale and it hooks from the first page. Plenty of great series start like that: with something small and personal that, bit by bit, turns out to be connected to something much bigger.
The two-sentence test
Before you write a line, try to summarise your story in two sentences without using any word you've invented. No kingdom names, no name for the magic, no races from your world.
For example: "An apprentice mapmaker discovers that the maps her master draws don't show the world, they change it. When he disappears, she has to decide whether to finish his last map, which would save her city but erase her parents'."
If you can do that, you have a story. If nothing is left once you remove the invented words ("Kaelith, last of the Vey'ra, must find the Orb of Thal before the Morghul awakens"), what you have is a set waiting for a story. That's fine, it's a very common starting point, but it's worth knowing before you write four hundred pages.
What keeps someone reading is always human: the fear of losing someone, ambition, guilt, the wish to belong somewhere, an injustice that can't be borne. The fantasy world is the stage where that conflict becomes bigger, stranger or harder, but the conflict has to exist without it.
The world: build only what the story walks on
Building your world, usually called worldbuilding, is the most fun and most dangerous part of writing fantasy. Fun because it never ends. Dangerous for precisely the same reason: you can spend three years designing an empire's economy, the languages of five peoples and the family trees of twelve dynasties without having written chapter one.
The rule that helps most is the iceberg: you know a lot, the reader sees a little, and what they see feels solid because there's more underneath. When a character avoids stepping on the black tiles in the temple and nobody explains why, the reader senses that this world has a history. You don't need the whole chapter about the religious war that started it. Sometimes the sentence that hints is worth more than the page that explains.
To keep your bearings, think about the world in layers and decide what your story needs from each one:
| Layer of the world | Useful questions | When it really matters |
|---|---|---|
| Geography and climate | How long does it take to get from one place to another? What season is it? What's scarce? | If there are journeys, wars or survival |
| Power and politics | Who's in charge, why do people obey them, and who wants their seat? | Almost always: conflict is usually born here |
| Economy | What do people live on? What's expensive? What's traded? | If your characters are poor, merchants or thieves |
| Beliefs and religion | What do they believe, what's forbidden, what's celebrated? | If there are taboos, fanaticism or moral dilemmas |
| History | What happened a hundred years ago that still hurts? | If the past explains the present conflict |
| Daily life | What do people eat, how do they greet each other, what counts as rude? | Always, in small doses: it's what makes a world believable |
| Magic | Who uses it, how, at what price, and what does everyone else think of it? | If it exists, in every scene where it appears |
Look at the last column. Not everything deserves the same amount of work. If your whole story takes place in a port city, you need to know that city very well: its districts, its guilds, its smells, what time the taverns close and who controls the docks. Whatever happens on the other side of the ocean can stay as a couple of rumours.

The everyday is what convinces
There's one detail that separates memorable worlds from ones that feel like cardboard sets, and it has nothing to do with magic or battles: everyday life. What people have for breakfast, how they pay for things, which insult is the worst, what you give a newborn, what children do when they've got nothing to do.
Two or three of those details, well placed, do more for a world's credibility than ten pages of ancient history. And they have a huge advantage: they don't stop the action. They slip into it. The character doesn't explain that in her city drinking water is a luxury; she simply pays more for a glass of water than for a beer, and the reader gets it on their own.
Magic: rules, limits and a price
If your world has magic, it's probably one of the first things you'll design and one of the ones that gives you the most trouble. The classic problem is this: if magic can do anything, there's no tension. Why worry about the hero if, at the decisive moment, she can cast a spell that fixes everything?
Among fantasy writers there's an idea usually credited to Brandon Sanderson that works very well as a compass: magic's ability to solve plot problems should be proportional to how well the reader understands how it works. In other words, if magic is going to save the day, the reader needs to know its rules in advance, so the solution feels clever rather than like the author pulling a trick.
That leads to two broad approaches, and both are valid:
- Magic with clear rules ("hard magic"). The reader understands how it works, what limits it and what it costs. It's almost like a science, and scenes where it's used can be solved with intelligence, like a good puzzle.
- Mysterious magic ("soft magic"). The reader doesn't know its rules, and the magic creates wonder, threat or a sense of the sacred. It works very well, with one condition: it can't be what resolves the conflict, because it would look as if the author had pulled the solution out of thin air.
Whichever you choose, answer three questions before you write:
- What can it do? Be concrete: not "control the elements" but "heat or cool an object you're touching".
- What can't it do? Limits are more interesting than powers, because they force characters to look for solutions.
- What does it cost? Exhaustion, years of life, memories, money, other people's rejection, health. Magic that costs nothing is magic that will never be frightening.
That last point is what really turns magic into story. If every spell steals a memory from your protagonist, every time she uses it the reader will wonder what she's lost this time. It's no longer a special effect, it's a decision with consequences.
And a practical warning: the rules of magic are the first ones you break by accident. In chapter four you say nobody can use magic at night, and in chapter twenty-two your protagonist uses it at midnight because it suited the scene. Readers notice. It's worth writing the rules down somewhere you always check, as you'll see further on.
Characters who outweigh the world
Here's a simple test: if you took away the magic and the dragons, would you still care about your characters? If the answer is yes, you're on the right track. If the characters only exist to show off the world ("the young farmhand who knows nothing and needs everything explained"), readers will end up seeing the strings.
For each important character, answer these questions:
- What do they want? Something concrete and their own, not "save the world". Get the family farm back, be acknowledged by their mother, pay off a debt, take revenge on someone.
- What stops them getting it? This is where the world comes in: laws, magic, where they come from, a war. The fantasy world is the obstacle, not the protagonist.
- What do they believe is true that isn't? The lie they tell themselves, which the story is going to test.
- What do they think of their own world? A character who criticises the rules of their society, or defends them fanatically, shows the world far better than a narrator describing it.
The chosen one, the mentor and the dark lord
Fantasy has very familiar figures: the orphan with a destiny, the wise mentor who dies halfway through, the dark lord who wants to rule everything just because. They aren't mistakes in themselves. Many novels we love use them. The problem comes when they run on autopilot.
A few questions to turn them around:
- What if the chosen one doesn't want to be chosen? Or worse: what if the prophecy has been misread and the chosen one was somebody else?
- What if the mentor is wrong? A mentor with flaws, fears or an agenda of their own is far more interesting than one who's always right.
- What does the villain want, and why do they think they're right? The most unsettling antagonist is the one who, from their point of view, is saving the world. If readers come to understand them, even without excusing them, the story gains a whole extra layer.
Our guide to creating compelling characters has more tools for giving them depth.
How to show the world without drowning the reader
Fantasy's most common mistake has a name of its own: the infodump. It's the moment when the story stops so that a character, or the narrator, can explain three centuries of history, the structure of the council of mages and why the northern elves don't speak to the southern ones.
Readers don't need to understand the world to enjoy the story. They need to understand just enough to follow the scene they're reading, and to trust that the rest will become clear. A few ways to manage it:
- Explain through conflict. The best moment to show how a law works is when a character is about to break it.
- Let characters take things for granted. People don't explain their own world to each other. Nobody tells their brother "as you know, the Tube comes every five minutes". If your characters do, it sounds false.
- One invented word per page, at most, at the start. If the first paragraph has six proper names and three magic terms, the reader is worn out before they begin.
- Context before glossary. If a word is clear from how it's used ("he paid her two copper moons and kept the third"), you don't need to define it.
- Spread out the revelations. Every fact about the world is a reward. If you hand them all out in chapter one, you've none left for the rest of the book.
The first chapter
In fantasy the first chapter carries extra pressure: it has to introduce a world and hook the reader at the same time. Many authors fall into two traps. The first is the history prologue: three pages about a battle a thousand years ago with characters who never appear again. The second is the quiet morning: the protagonist wakes up, has breakfast and walks around the village so the reader can get to know it.
What almost always works is to open with a character who wants something at a moment when something changes. The world becomes visible around them as they act. If by the end of chapter one the reader knows what the protagonist wants, what's stopping her and has sensed one or two strange things about this world, you're doing very well.
And the prologue? It can work, especially if it's short, has tension of its own and raises a question the book will answer. If it's only background, it's nearly always better to spread it through the story.
Names, languages and invented words
Names are one of the things readers notice most and writers think about least. A few rules that save a lot of trouble:
- Make them pronounceable. If readers don't know how to say your protagonist's name, they'll read it as a blur every time it appears. Apostrophes and impossible consonants look exotic the first time and tiresome the tenth.
- Make them different from each other. If you have Kael, Kaen and Kara in the same chapter, readers will mix them up. A useful rule: main characters should start with different letters and be different lengths.
- Keep them culturally consistent. Names from the same people should sound related. If in the north everyone has short, hard names and in the south long, soft ones, readers will know where someone's from before you tell them.
- Make sure they don't sound like something else. Read the names aloud and search for them online. Some kingdom names turn out, quite by accident, to match a brand of yoghurt.
- Spell them the same way every time. It sounds obvious, but in a 400-page book "Aldaren" ends up as "Aldarren" or "Alderan". Keep a list.
You don't need to invent an entire language. A handful of words with consistent rules (how they sound, how they form plurals, which letters don't exist) is enough to make the world feel rooted.
Do you need a glossary or a map?
A map is almost always welcome, especially if there are journeys. A glossary and a list of characters are useful in long series and in epic fantasy, at the back of the book. But if readers need to consult them to follow the story, the problem is in the text, not in the lack of appendices.
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The world bible: so nothing contradicts itself
If there's one genre where consistency matters more than any other, it's this one. In a realist novel, readers know how long it takes to get from London to Manchester. In your world, the only reference is what you've written. If in chapter six the trip from the capital to the port takes three weeks on horseback and in chapter twenty your characters do it in two days, readers don't think there's a shortcut. They think the author has forgotten.
And fantasy readers remember everything. They make maps, timelines and entire forums to check whether things fit.
The solution is to keep a world bible, a reference document where you record every fact that appears in the text. Not what you'd like your world to be, but what you've already written:
| What to record | Example |
|---|---|
| Characters | Nerea, 17, grey eyes, left-handed, scar on her right hand (ch. 2) |
| Places and distances | From Valdris to the port of Ossa: three weeks on horseback, five days by river (ch. 6) |
| Rules of magic | Doesn't work on iron; every use costs a memory; nobody can use it twice in a row (chs. 4 and 9) |
| Calendar and time | The thaw begins in the month of cranes; the story opens 40 days before it |
| Politics and relationships | The Duke of Arren and the queen are cousins; they swore loyalty in ch. 11 |
| Invented terms | "Copper moon": a low-value coin; "the silent ones": the temple priests |
| Secrets and who knows them | Only Ilán knows the master is still alive (from ch. 14) |
A spreadsheet with one row per item is enough. What matters is checking it before you write each chapter and going over it when you finish the draft. Our guide to broken manuscript syndrome explains why long books tend to contradict themselves just when they're furthest along, and the page on story bible software shows how to organise one.

Writing fantasy with AI without sounding like everyone else
AI can be a useful ally for writing fantasy, above all for something that weighs heavily in this genre: remembering. But it has tendencies worth knowing before you ask it for anything:
- Names that all sound alike. Ask for the name of a kingdom or a sorceress and it may well offer the same sounds it has offered thousands of other people: lots of "th", lots of "ae", lots of "-ia" endings. Ask it for options, but give it the sound rules for each people yourself and keep only what fits.
- Magic that fixes everything. Ask it to resolve a scene and AI tends to use magic as the easy way out, forgetting the price or the limits you'd set.
- Grandiose prose. Ancient prophecies, gathering shadows, destinies that await. Without clear guidance, AI-written fantasy sounds like a film trailer.
- Generic worlds. Tavern, elven forest, dragon mountain. What makes your world unique are the details only you have imagined, and those it can't guess.
Where it does help:
- Keeping the world bible up to date: who's who, where each place is, what rules the text has established.
- Spotting contradictions: a character whose eye colour changes, a distance that shrinks, a rule of magic that breaks.
- Suggesting complications for a specific point in the plot, which you then pick, change or throw out.
- Giving you variations on names or terms based on the rules you give it.
- Checking whether a chapter has too many invented words or an infodump that slows the action.
The key is the order: you decide first, then AI helps. You decide what the magic costs, who the villain is and why they think they're right, what secret each character is keeping. AI works within those decisions, not in their place. Our guide to writing a book with AI that sounds human has a three-pass method for removing the typical verbal tics.
And remember that KDP asks you to disclose AI-generated content when you publish. We explain it in what Amazon's AI policy says.
One book or a series?
Fantasy is the series genre par excellence, and it's tempting to plan a trilogy (or a seven-book cycle) before finishing the first book. There are good reasons to: readers of the genre love series, and on Amazon each book pushes the others.
But there's one rule worth respecting: the first book has to work on its own. It needs a conflict that's resolved within its pages, even if it leaves the bigger conflict open. If the reader reaches the last page feeling they've read a first act with no ending, they won't buy the second. If they feel they've lived through a complete story with more still to discover, they'll be waiting for it.
A few ways to achieve that:
- One closed goal per book, inside a bigger arc. In the first they escape the city; in the second they find the master; in the third they face what he left unfinished.
- A world that grows with each book. The first can be small and readers will be grateful; the third can open up the whole map.
- A world bible that stays with you for the whole series. Contradictions between books hurt the most, because readers find them when they reread.
We go into more detail in how to write a book series.
Revise the world, not just the sentences
When you finish the draft, the temptation is to start polishing sentences. Wait. In a fantasy novel, before you correct the style it's worth doing at least three readings with very specific questions:
- The story read. Is there a clear human conflict from the start? Does the protagonist make decisions, or just travel around the world so the reader can see it? Is the ending earned by what the characters do, or does magic resolve it?
- The world read. Mark every paragraph where the story stops to explain something. Ask whether the reader needs it at that exact moment. If not, cut it or move it.
- The consistency read. With the world bible beside you: names, distances, dates, rules of magic, who knows what at each point. It's the most tedious and the one that prevents the most bad reviews.
After those three, yes: sentences, pacing, dialogue. Our guide on how to revise a long manuscript before publishing covers the full process.
Fantasy readers, rather than readers in general
Real readers show you what you can no longer see, because you know the world and they don't. Our guide to beta readers explains how to find them. For a fantasy novel, try to have at least one who reads a lot of the genre and another who reads almost none: the first will catch the clichés and the second the parts that don't make sense. Four questions are worth more than "did you like it?":
- At what point did you get lost with the names or terms?
- Was there any part where you felt like skipping pages?
- Did the magic seem to solve things too easily?
- Explain to me in your own words how the magic works. (If they can't and your magic has rules, something hasn't made it onto the page.)

Publishing your fantasy novel on Amazon KDP
Once it's written and revised, publishing it on Amazon KDP has a few details specific to the genre:
| Step | What to bear in mind |
|---|---|
| Categories | Pick the specific subgenre, not just "Fantasy": epic, urban, dark, romantic, young adult. In a small, precise category it's easier to be seen by someone looking for exactly what you've written. |
| Keywords | Think about how your reader searches: "epic fantasy with dragons", "cozy fantasy", "hard magic system", "enemies to lovers fantasy". We explain it in Amazon KDP keywords and categories. |
| Cover | The subgenre is recognisable from the thumbnail: landscapes or weapons for epic, dark tones for grimdark, warm illustration for cozy, silhouettes and ornaments for romantic. The measurements are in Amazon KDP cover dimensions. |
| Map | You can include it in both the ebook and the print book. In print, watch the resolution and keep anything important away from the centre, where the page folds. In the ebook, make sure it's readable on small screens. |
| Length and price | A long book costs more to print, and that cuts your margin. If your novel runs past 120,000 words, run the numbers with the KDP royalty calculator before you set the price. |
| Series | If it's a series, set it up as one on KDP so the books appear together and readers can see which comes next. |
| KDP Select and Kindle Unlimited | Fantasy readers read a lot on Kindle Unlimited, and long books rack up plenty of pages read. We compare the options in KDP Select or going wide and in how much Amazon pays per page read. |
One tip for the book description: don't fill it with invented names. "In the kingdom of Valdris, the last bearer of the Seal of Ossa must face the Silent Ones" tells nothing to someone who hasn't read the book. "An apprentice mapmaker discovers her master's maps can change the world" does. It's the two-sentence test again.
How YourNovel handles it
If you write your fantasy novel in YourNovel.app, you have two routes and can mix them:
- Write it yourself, with help when you ask for it. The editor is free and unlimited, with chapters and scenes you can reorder as you like, autosave, focus mode, daily word goals and automatic versions. If you get stuck on a scene, the ideas chat knows your whole project and helps you find what it's missing.
- Start from what you already have. If you have a draft in Word, PDF or plain text, you import it and the AI analyses it, organises it into chapters and fills in the character and place profiles so you can carry on from there.
For a fantasy novel, this is what helps most:
- The story bible. YourNovel pulls the characters, places and key facts out of your text and keeps them to hand: your protagonist's scar, the distance between the capital and the port, or what each spell costs.
- Memory of the whole book. The AI keeps what you've already written in mind, so your characters are less likely to forget a rule of magic or a pact from chapter eleven.
- Analysis tools inside the editor. The consistency checker looks for contradictions in characters, time and places, with the chapter flagged. Pacing analysis helps you see where the story stalls, which in fantasy is usually where the world gets explained. The plot twist generator lends a hand when the story needs a complication. They show you where to look, but you decide what's a mistake and what's a deliberate choice.
- Global revision with your instructions. For example: "flag the paragraphs where the action stops to explain the world's history" or "mark the scenes where magic is used without paying its price". It reviews the book section by section and suggests changes that you accept one by one or, if you confirm, all at once. Nothing changes without your approval, and before the first change a copy is saved in Versions. There's a limit on revisions per period depending on your plan, and anything that depends on comparing the whole book is worth checking by hand as well.
- AI beta reader. A critical read of your manuscript before you show it to anyone. The sample of the first 5,000 words is free with an account: you can try it with the YourNovel AI beta reader.
- Export and cover. You download the book as a KDP-ready PDF or Word file, and paid plans include a cover designer with Amazon's measurements calculated from your page count.
AI is a help. The price of the magic, the villain's secret and the book's final image are still yours.
The most common mistakes
- Stopping the story to explain the world. Readers want to know what happens, not how the kingdom was founded.
- Too many names at the start. Six characters, three kingdoms and two orders of mages in chapter one would wear anyone out.
- Magic with no price. If it can solve everything, nothing is in danger.
- Breaking your own rules. The magic that didn't work at night, working at night.
- Characters who exist to show off the world. The apprentice who needs everything explained and wants nothing for himself.
- A villain who's evil just because. Without motives, they aren't frightening; they're tedious.
- Distances and times that change to suit you. The three-week journey that, when needed, takes two days.
- A first book with no ending. If everything is saved for part two, readers won't get there.
- Film-trailer prose. Gathering shadows, waiting destinies, ancient prophecies on every page.
Frequently asked questions
How many words should a fantasy novel be? Most fall between 80,000 and 120,000 words, roughly 320 to 480 pages. Epic fantasy can go beyond 150,000, while young adult and cozy fantasy usually sit between 60,000 and 90,000. If it's your first novel, it's best not to go much past 120,000: it's easier to finish, to revise and, in print, to sell at a reasonable price.
How do you create a fantasy world from scratch? Start with the story, not the map. Decide what conflict you want to tell and build the layers of the world that conflict needs: geography, power, economy, beliefs, history, daily life and magic. Know far more than you'll tell, record it in a world bible and let readers discover it gradually, through what the characters do.
How do you design a magic system? Answer three questions: what it can do, what it can't do and what it costs. The limits and the price are what turn magic into story. If magic is going to resolve the final conflict, readers need to know its rules beforehand. If you prefer mysterious magic, use it to create wonder or threat, not to rescue the protagonist.
Do I have to include a map? No, but fantasy readers usually appreciate one, especially if there are journeys or wars. It should help readers follow the story, not decorate it: the important places, at the right distances and with the same names as in the text. On KDP you can include it in both the ebook and the print book.
How do you come up with good fantasy names? Make them pronounceable, different from one another, related within each people, and spelled the same way every time. A practical rule: main characters should start with different letters. And search for them online before you commit.
Can you write a fantasy novel with AI? Yes, as long as you're the one deciding the conflict, the rules of the magic and who the characters are. AI helps above all with remembering: keeping the world bible, spotting contradictions and suggesting complications. Without guidance, it drifts towards repeated names, generic worlds and magic that solves everything. On KDP you must disclose AI-generated content.
Is it better to write a standalone or a series? In fantasy, series work very well, because readers of the genre read them in full. But the first book has to stand on its own, with a conflict that's resolved within its pages. If it doesn't, readers won't buy the second. If you're unsure, write the first as if it were the only one and leave some doors open.
The world only you know
Some worlds have been waiting for years inside someone's head. With their mountains, their cities, their laws and their names. Sometimes they began in the margin of an exercise book, sometimes in a role-playing game with friends, sometimes in a dream that didn't fade on waking. Nobody else has seen them. And the only way for them to exist for anyone but you is to write them.
You don't need to know everything about your world to start. You need someone who wants something, a world that makes it hard for them, and the will to stay with them to the end. The rest reveals itself along the way, to you as well.
If you want to start, at YourNovel.app you can write your novel in the free editor or import the draft you already have, keep your world bible up to date and take the book all the way to the PDF and the KDP cover without switching tools. And if it's already finished, run it through the manuscript checker first to find out how many pages you're working with.