AI grand strategy — in your browser

Open Historia

Rewrite history. Command nations in plain English.

Type “invade Bohemia” or “send envoy to the Ottoman court.” An AI Game Master moves armies, shifts treaties, and remembers your campaign across 20+ scenarios from 793 AD to 2040.

Pick a scenario and start

Free · open source · bring your own AI key or use the free tier · GitHub

·  THE PITCH  ·

The world’s most opinionated Game Master.

Every Paradox game ships with hard-coded events and scripted ledgers. Open Historia ships with an LLM. You type “invade Bohemia” or “send envoy to Ottoman court” and the AI returns the consequences — armies move, treaties shift, relations decay or warm. The Game Master keeps a running summary of your campaign so the world remembers, turn after turn.

Same map. Same start year. Wildly different histories.
·  FEATURES  ·

Three building blocks. Endless campaigns.

I

Multi-provider AI

Anthropic, OpenAI, Gemini, DeepSeek, or local. Bring your own key, pick your model per session.

II

Save & share

Turso-backed cloud saves. Resume anywhere, share a campaign URL, fork a friend’s timeline.

III

Alternate history

Rewind to any turn. Branch off. The Game Master rolls the world forward from your new decision.

·  LAUNCH  ·

Pick a scenario.
Rewrite the rest.

20+ presets — historical, modern, alternate, fictional. Or write your own start year, your own nation, your own brief to the Game Master.

Pick a scenario and start
Free · open source · GitHub