# ChronoForge > ChronoForge turns a lesson into a playable decision story. A learner takes a role inside a moment that mattered (a crisis, a text, an investigation), follows leads, questions the people around them, makes decisions that cost something, and then compares their path with what really happened: the historical record, the source text, the scientific evidence or expert practice. Teachers own the facts of a world; AI performs them live. It is a learning research project of VIABLE Lab, a learning-science research lab at the University of Florida, and runs on the VIABLE Developer Platform. Key facts: - Who it is for: learners and their teachers, in any subject with a decision in it. Each world is written for one audience: ages 11-14, ages 14-18, undergraduates or adult learners. - How a chapter plays: each chapter is one real decision, in six beats. Arrive in a dated scene, investigate leads that each hold a true, checkable clue, ask anyone in the room a question, work something out from the evidence, decide, then see the consequence. At the end the learner's timeline sits beside the record. - What is fixed and what AI does: the teacher fixes the skeleton, which is the same for every learner: the role, the stakes, the chapters, every option and what it costs, the clues and their sources, the checks and their answers, and what really happened. AI writes the dialogue, answers the learner's own questions in character, judges whether a learner's own move was possible in that time and place, and writes the consequences, the ending and the debrief. The engine, not a model, moves the stakes, decides endings and marks checks. - Work it out: every chapter has one or two checks answered from the evidence on screen: a number to calculate, a choice whose wrong answers are real misconceptions, or a written claim with evidence. A hint follows a first wrong try, and the worked answer appears once the check is done. No AI grades the learner. - Checked replies: when a learner questions a character or writes a reflection, a VETTING reviewer checks the AI's reply before the learner sees it. - After the story: a debrief compares the learner's path with the record and asks why the real people chose as they did. The learner can rewind to any chapter and try another path, write a reflection that a coach answers with one question, and fill in a five-item questionnaire. - For teachers: a class has one join code and any number of worlds, in the teacher's order. A teacher can adapt a world for a class without changing its skeleton (a note for the AI, simpler language, extra checks and reflection questions), and sees how each decision split beside the record, how sure learners were, how each check went and which questions were asked. - World Studio: a teacher builds a world from their own lesson and files (PDF, Word, Excel, OpenDocument, HTML, CSV, Markdown or text, up to 8 files of 10 MB each). An AI architect drafts it, usually in one to two minutes, a reviewer checks the draft against the design rubric, and the teacher edits every word. A world is private until its author lists it in the library, and a world is listed only after review. - On other sites: a world or a class can be put on Canvas, Google Sites or any page that takes an iframe, as a card that opens ChronoForge in a new tab. There is no LTI integration, and nothing reaches an LMS gradebook. - Sign-in: everyone signs in with Google to play, build a world or run a class. There are no guest accounts. The world library and each built-in world's page can be read without signing in. - Cost: there is no charge. Each account has a daily AI allowance set by VIABLE Lab (one playthrough uses roughly 10 to 15 units) and a separate daily limit on spoken lines. Teachers can ask VIABLE Lab for more. - Research and data: ChronoForge is a research project. What learners do in a story is recorded, their teacher sees their work in class, and researchers work from an export with no names or emails, in which accounts and classes are replaced by codes. Any learner can turn research off, and a teacher can keep a class out of it. - Language: the built-in worlds are in English, with painted scenes and optional spoken lines. ## Pages - [Home](https://forge.viablelab.org/): what ChronoForge is, a scene to try, the six beats of a chapter, and how teachers use it. - [Worlds](https://forge.viablelab.org/worlds): the library of worlds to play, by subject and audience. - [Research and your data](https://forge.viablelab.org/research): what is recorded, who can see it, the research export, and how to turn research off. ## Built-in worlds One world per subject. Each page shows the role, the setting, what learners practice and how long it takes. - [Thirteen Days](https://forge.viablelab.org/worlds/cuban-missile-crisis): History, October 1962, ages 14-18. Soviet nuclear missiles are 90 miles from Florida, and the people around the President have days to stop a war nobody wants. - [The Broad Street Pump](https://forge.viablelab.org/worlds/broad-street-pump): Science, September 1854 - 1855, ages 14-18. Hundreds of your neighbors are dying of cholera, and the only clue is where they got their water. - [The Friar's Remedy](https://forge.viablelab.org/worlds/friar-laurence): Literature, Shakespeare's Romeo and Juliet (c. 1595), ages 14-18. Two teenagers from enemy families beg you for help, and every plan you make to save them has to work faster than fate. - [The Black Armbands](https://forge.viablelab.org/worlds/tinker-armbands): Civics, December 1965 - February 1969, ages 11-14. Your best friend is about to wear a black armband to school, the principals just banned it, and the fight will go all the way to the Supreme Court. - [Before This Decade Is Out](https://forge.viablelab.org/worlds/moon-landing): Engineering, 1962 - 1969, ages 14-18. Kennedy promised the Moon by 1970, and now engineers like you have to decide which risks are worth an astronaut's life. - [Bread for Billions](https://forge.viablelab.org/worlds/weimar-bread): Economics, January - November 1923, ages 14-18. In 1923 the price of your bread doubles every few days, and every way you protect your family's bakery hurts someone else. - [The Lady's Numbers](https://forge.viablelab.org/worlds/nightingale-roses): Math, January 1855 - 1858, ages 14-18. Soldiers are dying faster than anyone can bury them, and the numbers in your ledger might be the only thing that can change the British Army. - [The Pentagon Papers](https://forge.viablelab.org/worlds/pentagon-papers): Ethics, June 1971, undergraduates. A secret history of the Vietnam War lands on your desk days after a court silenced the New York Times, and publishing it could sink your newspaper. ## Where teachers start These need a Google sign-in. - [World Studio](https://forge.viablelab.org/create): build a world from your own lesson. - [Teach](https://forge.viablelab.org/teach): make a class, add worlds and share its join code. - [My classes](https://forge.viablelab.org/join): where a learner types a class code. ## The VIABLE family - [VIABLE Lab](https://www.viablelab.org): the research lab that makes ChronoForge. - [VIABLE Developer Platform](https://developers.viablelab.org): what ChronoForge's AI runs on: published agents, VETTING, request logs and learner records. - [VIABLE Learning Platform](https://www.viablelearning.org): where a teacher sets up a class by saying what they are teaching, and where learners join it. - [LOGEN AI](https://logen.viablelab.org): helps educators write clear, measurable learning objectives with Bloom's taxonomy. - [VIABLE Open Kit](https://github.com/VIABLE-Learning-Lab/viable): VIABLE's public code, MIT licensed: the VIABLE Harness and the VIABLE Engine. ## About - [Contact VIABLE Lab](https://www.viablelab.org/contact)