What High Valyrian Teaches Fantasy Writers About Creating Believable Languages

For high valyrian fantasy writers, believable languages start with rules, not decoration.

Fantasy writers love inventing languages. A few Elvish-sounding words here, an untranslatable curse there, and suddenly a world feels deeper. But most invented languages in fiction collapse the moment a reader looks closely: the grammar contradicts itself, the vocabulary is a random grab bag, and the “ancient tongue” sounds suspiciously like English with the vowels swapped.

High Valyrian — the language David J. Peterson created for Game of Thrones and House of the Dragon — is one of the rare fictional languages that holds up under scrutiny. It was built by a professional linguist with a complete grammatical system, and studying how it works offers practical lessons for any writer building a language of their own. Not to copy it, but to understand why it feels real.

Lesson 1: For high valyrian fantasy writers, a small, rule-driven vocabulary beats a large, random one

New conlangers often try to invent hundreds of words. Peterson’s approach is different: High Valyrian works from a documented set of roots and derivation rules, so new words are built rather than improvised. The vocabulary is deliberately finite — a few thousand words — but because the word-building rules are consistent, the language can express anything its speakers need.

For high valyrian fantasy writers, the takeaway is direct. You don’t need a 10,000-word lexicon for your novel. You need maybe two hundred words — names, curses, titles, greetings, terms of power — plus a handful of rules for how new words form. Decide how your language builds compounds. Decide what its roots sound like. Then derive everything else from those roots. A reader will notice the consistency of your words far more than their quantity.

Lesson 2: Give the grammar constraints, not just decoration

High Valyrian’s grammar has real structure: a subject-object-verb word order (unlike English’s subject-verb-object), eight noun cases, four noun classes, and seven verb tenses. These aren’t flavor text — they determine how every sentence in the language must be built. When Daenerys says “Zaldrizes buzdari iksos daor” (“A dragon is not a slave”), the sentence obeys rules that apply equally to any other sentence.

High valyrian fantasy writers don’t need anything this elaborate for a novel. But pick three or four grammatical rules and never break them. Maybe your language always puts the verb last. Maybe it marks plurals with a prefix instead of a suffix. Maybe it has no word for “please” because the culture has no concept of polite requests. A few unbreakable rules create the illusion of a whole system — and readers are remarkably good at sensing when a system exists versus when words are just being made up on the spot.

Lesson 3: The sound of the language should fit the culture

High Valyrian sounds the way it does for a reason. Its long vowels, rolling consonants, and measured rhythm fit a fallen empire — a language of law, ceremony, and old power, now spoken mostly as a prestige tongue by people who want to sound educated. It doesn’t sound like Dothraki, the harsh steppe language of the same world, because it shouldn’t: these are different peoples with different histories.

When you design words for your world, ask what the culture values. A merchant republic’s language might be clipped and efficient. A theocracy’s might be full of long, chantable vowels. A mountain people’s speech might favor hard consonants you can shout across a valley. The sound is worldbuilding. If your warlike horde and your ancient priesthood speak languages that sound interchangeable, you’ve missed an opportunity.

Lesson 4: Let the language change over time

One of the most realistic things about Peterson’s work is that High Valyrian isn’t static. The show features its descendants — Astapori Valyrian and Meereenese Valyrian, the “Bastard Valyrian” of Slaver’s Bay — which have drifted from the classical form the way Romance languages drifted from Latin. Sounds shifted, grammar simplified, vocabulary mixed with local tongues.

Real languages always change, and readers intuitively expect it. If your story spans centuries or continents, consider giving your language a daughter dialect or two. A few systematic sound changes — every “k” becomes “ch” in the southern dialect, say — will do more for realism than a hundred random new words. Even a single line of dialogue where a character struggles to understand an archaic inscription tells the reader this language has history.

Lesson 5: Build pragmatics, not just words

The most famous High Valyrian isn’t a word at all — it’s an exchange. “Valar morghulis” (“All men must die”) is always answered with “Valar dohaeris” (“All men must serve”). That’s not vocabulary or grammar; it’s pragmatics — the unwritten rules of how language is used between people. Greetings, oaths, blessings, insults, and ritual phrases are what make a fictional language feel lived in.

For high valyrian fantasy writers, invent five fixed expressions before you invent five hundred words: a greeting, a farewell, a curse, an oath, and something people say when they’re surprised. Use them consistently. Readers will remember these phrases long after they’ve forgotten your grammar — and they’ll quote them back to you, which is the highest compliment a fictional language can earn.

High valyrian fantasy writers: putting it to work

You don’t need a linguistics degree to build a believable language for your story. Start with these five decisions: (1) twenty roots and the rules for combining them, (2) three unbreakable grammar rules, (3) a sound that matches the culture, (4) one way the language has changed over time, and (5) five fixed expressions your characters actually say. Write those down on a single page and keep it beside you while you draft. Everything else — every new name, curse, and battle cry — derives from that page.

And if you want to study a working example up close, a free searchable High Valyrian dictionary is a good place to see how a professional conlang organizes its vocabulary: https://highvalyriantranslators.com/high-valyrian-dictionary/

The goal was never to speak High Valyrian. The goal is to learn, from someone who did the work properly, what “properly” looks like — and then to do it for your own world.

Amir Hussain is the founder of High Valyrian Translators, where he maintains free High Valyrian learning tools, a 400-word dictionary, and beginner grammar guides.