Dothraki and Valyrian: How David Peterson Built Two Real Conlangs

In 2009, HBO needed a language for the Dothraki people in its upcoming adaptation of George R.R. Martin's A Song of Ice and Fire. The network did not hire a linguist directly. Instead, the Language Creation Society ran a competition. More than 30 conlangers submitted proposals. The winner was David J. Peterson, a 28-year-old linguistics graduate student at UC San Diego who had been building languages since he was a teenager.

Peterson delivered over 1,700 words to HBO before the first episode of Game of Thrones aired in April 2011. The vocabulary has since grown to over 3,000 Dothraki words and over 2,000 High Valyrian words. The Economist called them "the most convincing fictional tongues since Elvish." A Duolingo course for High Valyrian launched in 2023 and has attracted 3.2 million learners. Peterson also created the Dune sign languages for Denis Villeneuve's film adaptations.

You can experiment with the vocabulary using our Dothraki and Valyrian translator. It is a word-level dictionary tool, not a full grammar engine, but it gives you a feel for the phonology and lexicon Peterson designed.

The Language Creation Society is a non-profit organization founded in 2007 to promote the art and craft of constructed languages. When HBO approached the society about creating a Dothraki language for Game of Thrones, the society proposed a competition rather than recommending a single person. According to the Wikipedia article on Dothraki, more than 30 conlangers submitted complete language proposals.

Each submission had to include a phonology, a grammar, a writing system description, and a vocabulary of at least 300 words. The submissions were judged on linguistic plausibility, aesthetic coherence, and suitability for the Dothraki culture as described in Martin's novels. Peterson's submission won. He had been building languages since he was 16 and had created over 20 conlangs before the competition, including one for a class project at UC Berkeley and several for personal use.

Peterson's winning proposal drew on his knowledge of natural languages with unusual phonological and grammatical features. He designed Dothraki to sound harsh and guttural, matching the horse-riding warrior culture of the Dothraki Sea. He selected consonants that occur in languages like Arabic and Russian but are absent from English, including uvular stops and pharyngeal fricatives. The vowel system is small, with only four vowels, which is common in languages with rich consonant inventories.

HBO gave Peterson the job in early 2010. He had about a year to expand the vocabulary and prepare dialogue for the first season. He delivered over 1,700 words before the premiere, along with pronunciation guides and audio recordings for the cast. The dothraki.org website, which Peterson maintains, documents the full vocabulary and grammar.

Dothraki is the language of the nomadic horse-riding people in Game of Thrones. Peterson built it to reflect the culture George R.R. Martin described in the novels. The vocabulary is heavy with words related to horses, riding, weapons, and combat. There are reportedly over a dozen words for "horse" alone, distinguishing between stallions, mares, foals, warhorses, and packhorses. This is similar to how Arabic has multiple words for "camel" or how Sanskrit has multiple words for "elephant."

The phonology is designed to sound harsh to English-speaking ears. Peterson included uvular consonants (q and qh), pharyngeal consonants (the voiced and voiceless pharyngeal fricatives), and ejective stops. These sounds are common in languages of the Middle East and the Caucasus but absent from most European languages. The result is a language that sounds foreign and aggressive, which matches the way the Dothraki are portrayed in the show.

The grammar is agglutinative with a case system. Dothraki has eight cases: nominative, accusative, genitive, allative, ablative, locative, comitative, and vocative. Word order is subject-verb-object, like English, but the case markers allow flexibility. The verb system marks for person, number, and aspect. There is no grammatical gender, which is unusual for a language inspired partly by Russian and Arabic, both of which have gender systems.

Peterson drew inspiration from several natural languages. The consonant inventory was influenced by Arabic and Russian. The vowel system was inspired by languages with small vowel inventories like Spanish and Japanese. The agglutinative morphology was influenced by Turkish and Swahili. The case system was partly inspired by Estonian and Finnish. Peterson has said in interviews that he wanted Dothraki to feel like a real language that could have existed, not like a patchwork of features. The sources are inspirations, not direct copies.

The cultural impact was immediate. In 2012, the year after Game of Thrones premiered, 146 babies in the United States were named Khaleesi, the Dothraki word for "queen" or "ruler's wife." The name entered the top 1,000 baby names in the US Social Security Administration database. Peterson has commented on this phenomenon with a mix of amusement and concern, noting that "Khaleesi" is a title, not a personal name, in the Dothraki language.

High Valyrian is the second major language Peterson built for Game of Thrones. It is the classical language of the Valyrian Freehold, an ancient empire in the world of A Song of Ice and Fire. In the show, High Valyrian functions like Latin in medieval Europe: a dead language used for scholarship, ceremony, and elite communication. Characters who speak High Valyrian are signaling education and status.

Peterson designed High Valyrian with a different phonological profile from Dothraki. Where Dothraki is harsh and guttural, High Valyrian is flowing and melodic. The consonant inventory lacks the uvular and pharyngeal sounds that define Dothraki. The vowel system is larger, with long and short vowel distinctions. The overall sound is closer to Latin or Greek, which is appropriate given the language's role as a classical tongue.

The most distinctive feature of High Valyrian is its noun class system. Peterson designed four genders: Lunar, Solar, Aquatic, and Terrestrial. These are not biological genders but semantic categories. Words for celestial bodies go in the Lunar or Solar class. Words for water-related concepts go in the Aquatic class. Words for land-related concepts go in the Terrestrial class. There are also words that do not fit neatly into any category, and their class assignment is partly arbitrary, similar to how French or German gender assignment has semantic patterns but also many exceptions.

The noun class system affects agreement. Adjectives, participles, and some verbs must agree with the noun's class. This is similar to the gender agreement systems in Romance languages, but with four categories instead of two or three. The system also affects case marking, with different declension patterns for each class.

High Valyrian has eight cases: nominative, accusative, genitive, dative, ablative, locative, instrumental, and vocative. The verb system marks for person, number, tense, voice, and mood. Peterson has documented over 2,000 words, and the vocabulary continues to grow through his work on the House of the Dragon prequel series, which features additional Valyrian dialogue.

The Duolingo High Valyrian course launched in July 2023. According to Duolingo, the course has attracted 3.2 million learners as of 2026. This makes High Valyrian one of the most-studied constructed languages on the platform, alongside Klingon. The course covers vocabulary, grammar, and pronunciation, and it is free to access. Peterson consulted on the course content to ensure accuracy.

David Peterson has built languages for over 50 television shows, films, and video games. His credits include Defiance (Syfy), The 100 (CW), Thor: The Dark World (Marvel), and The Witcher (Netflix). He also created the sign languages for Denis Villeneuve's Dune films, including the hand signals used by the Bene Gesserit and the Fremen.

The Dune sign languages are a different kind of conlang. They are visual-gestural languages, not spoken ones. Peterson worked with deaf consultants and ASL experts to design a sign system that looked plausible on screen while being distinct from American Sign Language. The Bene Gesserit hand signals in Dune: Part One (2021) and Dune: Part Two (2024) are a simplified combat-sign system, not a full language. The Fremen signs in Part Two are more extensive, reflecting the culture's need for silent communication in the desert.

Peterson documents his work on his personal website, dedalvs.com, where he posts grammar sketches, vocabulary lists, and essays on language creation. The site also hosts the Living Language Dothraki guide, a printed reference book Peterson published in 2015 with Living Language, a language-learning publisher. The guide includes a 300-word vocabulary, pronunciation audio, and grammar lessons. It is one of the few published conlang textbooks available in print.

Peterson also served as president of the Language Creation Society and has been a vocal advocate for professional recognition of conlangers in the film and television industry. Before the Game of Thrones competition, language creation for media was often unpaid or done as a favor. Peterson's work on Game of Thrones helped establish the precedent that conlangers should be paid professionals, credited alongside other creative contributors to a production.

Game of Thrones ended in 2019 after eight seasons. The show's finale was controversial, and the prequel series House of the Dragon (2022-present) has a different cast and setting. But the languages Peterson built have outlived the original show's run. The Duolingo course continues to attract learners. The dothraki.org website continues to receive traffic. And House of the Dragon has introduced new Valyrian dialogue, requiring Peterson to expand the vocabulary further.

The endurance of these languages comes down to two factors. First, Peterson built them as complete linguistic systems, not as collections of cool-sounding words. Dothraki has a case system, a verb conjugation paradigm, and a documented phonology. High Valyrian has a noun class system, agreement rules, and a consistent derivational morphology. You can learn these languages the way you would learn any natural language, because they have the structural depth to support learning.

Second, the community has taken ownership. The Language Creation Society, the Duolingo course, and various fan wikis have created infrastructure for learners. Peterson remains involved, but the languages no longer depend solely on him. This is the same pattern that kept Klingon alive after Marc Okrand reduced his involvement, and the same pattern that keeps Tolkien's Elvish alive through the efforts of scholars at the Tolkien Gateway and other communities.

You can compare the structure of these languages to other conlangs using our tools. The Na'vi translator covers a language with a similar level of grammatical completeness. The Quenya and Sindarin translator handles Tolkien's Elvish, which has the longest history of any fictional language community. The Aurebesh translator covers a Star Wars script that is a simpler letter-substitution system rather than a full language. The range of complexity across these tools shows how different the craft of fictional language can be, from phonetic substitution ciphers to full grammatical systems with case marking and noun classes.