Synthasia is a revolutionary, infinitely replayable text-based RPG where you don't just play a story—you bring it to life. What if every door you opened led to a place that hadn't existed moments before? What if every character you met had their own thoughts, not just a script? What if a game world could grow, change, and remember you, all orchestrated by a creative AI Game Master?
Welcome to a boundless adventure where the story writes itself as you play.
A Living World, Powered by AI
Synthasia is not a typical RPG. There are no pre-written dialogue trees, no finite quest lines, and no static, unchanging maps. At its core is a powerful AI Game Master that generates the world around you in rich, descriptive prose. From the atmospheric text of forgotten starships and mystical forests to the unique items you discover along the way, every element is generated and expanded upon in real-time, creating a truly unique adventure every time you play.
Unscripted Lives, Genuine Conversations
Converse with characters who remember your past interactions and have their own goals and evolving personalities. The AI gives life to every NPC, allowing for unscripted, dynamic conversations where you can ask anything you want. Persuade, intimidate, or charm your way through complex social situations. The relationships you build and the enmities you forge are genuine, shaping how the world and its inhabitants react to your presence.
Bring Your Own AI: Your Engine, Your Story
Synthasia is a unique interface that acts as the 'game' layer on top of a Large Language Model (LLM). To play, you must connect to your own AI provider. This approach gives you complete control over your experience, from the AI's personality to your data privacy (multiple free options available).
This game does not include its own LLM. You are responsible for any costs associated with third-party services.
We currently support:
Local LLMs:Â Connect to your own computer's AI through Ollama, LMStudio, or KoboldAI for a private and highly customizable experience.
External Services: Use OpenRouter to access a wide variety of the latest and greatest models from providers like OpenAI, Google, and Anthropic.
Multiple LLM support builtin
SYNTHASIA uses multiple LLMs allowing users to minimize expenses and maximize speed. Configure 1 LLM that will be used for main descriptions and dialogues as well as rare but more complex task, and a secondary LLM which can be much smaller, faster, cheaper and easy to run locally which will take over many smaller but numerous tasks.
Create Worlds from a Single Idea - The "Create Game" button
Become the Game Master with the integrated World Editor. You have two powerful ways to create:
The Dreamer: Write a simple prompt—a single sentence or a short paragraph—and watch as the AI generates an entire game world for you, complete with lore, locations, and characters.
The Author:Â Meticulously design your own saga. Craft a detailed framework of locations, characters, items, and plot points, and the AI will act as your co-writer, fleshing out your world with rich descriptions and running it as a dynamic, interactive experience.
Share your creations with the community and explore theirs.
Features
A Truly Dynamic, Text-Based World:Â Immerse yourself in an ever-expanding story where new locations are generated by the AI as you discover them, complete with unique descriptions, points of interest, and items.
Unscripted AI Characters:Â Engage in genuine, text-based conversations with NPCs who have persistent memories, distinct personalities, and their own secret goals.
Your Choices, Your Story: Forge your own path in a narrative without guardrails. Your actions and words create ripples that the AI Game Master uses to shape the evolving story.
AI-Powered Visuals:Â While the gameplay is text-based, every character and location is visualized with unique, AI-generated artwork that brings your emergent adventure to life.
Choose Your Art Style: Take control of the visual tone. Use the Art Style selector to guide the AI in generating images in a variety of styles, from Realistic to Anime to Comic Book.
Customizable UI Skins: Tailor the game's look and feel to your liking with a powerful skinning system. Choose from built-in themes or create and share your own.
Create Any Character:Â Design your protagonist with a flexible stat and skill system, then watch as the world reacts to the unique individual you've created.
Why Early Access? A Journey We'll Take Together
Synthasia is more than a game; it's an exploration into a new frontier of interactive storytelling. The AI technology at its heart is groundbreaking and full of incredible potential, but it's also in its infancy. We are launching in Early Access because we believe the best way to build this new kind of experience is to do it openly and collaboratively with you, the players.
[b]This isn't just Early Access; it's a collaborative experiment.[/b]
Our goal is to create not just a single game, but a powerful and intuitive engine for emergent narrative. By joining us in Early Access, you become a vital part of the development process. Your stories, your feedback on the AI's creativity and logic, and your ideas for new features will directly influence the engine's evolution. You won't just be playing the game—you'll be helping us teach the AI how to be a better Game Master.
Join us on the ground floor. Help us shape the future of storytelling. Your adventure is waiting to be written.
