Undercurrent
An engine for plausible counterfactual history — and a way to measure its plausibility.
The Archduke's motorcade turned into Franz Josef Strasse.
▸ the driver held the Quay, as the amended route required.
The room
You are given an ordinary life at a hinge of the century.
A waiter in a Vienna café, winter 1913. A printer setting type in Beijing the night the People's Republic is proclaimed. A neighbour at a Berlin checkpoint on the ninth of November. You hold no office and command no army — only persuasion, information, and presence.
Press on the moment and the engine does not announce that you changed history. It answers with a fan of futures — each plausible given the real forces in the room, each weighted, one committed by the draw. Deep structures resist. Small hinges move. Consequences compound down the decades, and every win carries its blowback.
There is no score and no victory screen. At the end you are left with the shape of the century your choices produced — and a ledger showing exactly where it diverged from the one that happened.
Specimen · Vienna, 1913 · a word placed with the young editor
- 0.55The quarrel cools; the pact holds through winter.
- 0.30It holds — but the Georgian remembers who arranged it.committed
- 0.15Word reaches the wrong table, and the room goes quiet.
The file · scope
The first canvas is the twentieth century entire.
Forty-eight scenes across six thematic currents — ideas, money, empire, the made world, ecology, the image — that intersect and compound: a pact softened in a Vienna café is in the room at Smolny four years later. A run threads a dozen of them; no two runs thread the same century.
The century is the proof, not the limit. The engine underneath — plausibility-constrained resolution, persistent consequence, expert grading — is fully adaptable: it can tighten its frame to a single decade, a movement, a crisis, or another field's history altogether.
| I | II | III | IV | V | VI | VII | VIII | |
|---|---|---|---|---|---|---|---|---|
| Ideasplayable now | 1913Vienna — the café | 1917Petrograd — Smolny | 1937Barcelona | 1949Beijing — the gate | 1968Paris — the Sorbonne | 1989Berlin — the checkpoint | 2001New York — the smoke | 2011Tahrir Square |
| Money | 1907████████ | 1929████████ | 1944████████ | 1948████████ | 1971████████ | 1986████████ | 2008████████ | 2009████████ |
| Empire | 1905████████ | 1919████████ | 1941████████ | 1955████████ | 1975████████ | 1990████████ | 2003████████ | 2013████████ |
| Made world | 1903████████ | 1927████████ | 1945████████ | 1947████████ | 1969████████ | 1989████████ | 2007████████ | 2017████████ |
| Ecology | 1901████████ | 1925████████ | 1934████████ | 1954████████ | 1973████████ | 1987████████ | 1997████████ | 2015████████ |
| Image | 1900████████ | 1920████████ | 1938████████ | 1954████████ | 1968████████ | 1981████████ | 2004████████ | 2016████████ |
Forty-eight scenes are authored or specified. Their titles, and how they feed one another — the carried variables, the eligibility gates, the doorways a bend opens or closes — stay in the file. The playable current is shown.
The file · method
Counterfactuals earn their place only when disciplined.
The design is an engineering read of the argument historians made in Virtual History: alternatives restricted to what contemporaries actually weighed, reasoned from how events really worked — never from how a story wants them to go.
Two constraints are load-bearing. Plausibility — an outcome is offered only if it is credible given the real forces and what the people in the room could actually have done. Contingency — no determinism; the same moment can branch, but only along lines a serious historian would grant.
Stress · self-play
AI agents play thousands of full runs against the engine — five temperaments, full conversations, reasoning traces kept. Volume surfaces the exact moments the engine drifts toward drama over plausibility, and tests the central claim: that different play yields genuinely different, still-credible centuries.
Ground truth · the human corpus
We have spent many hours honing the engine's sense of the plausible — and we are not historians. A model can see only a fraction of the possibilities a scholar of the period can. So every resolution is logged, and invited historians flag the implausible ones and write why. That growing record of expert judgment disciplines the engine over time. It is the system's conscience, and its most defensible asset.
“That would not have followed, because —”the unit of value · one flagged objection at a time
The room · access
Undercurrent is in closed review.
The first current — the revolutionary century, Vienna 1913 to Tahrir 2011 — is playable end to end. We are inviting a small number of readers in before opening the doors wider.
- Historians — grade what the engine produced; your objections train it.
- Institutions & educators — pilot it as a seminar instrument.
- Media & partners — talk to us about scenario collaborations.
Playtester entry · Vienna 1913 slice
Begin from one of the four mouths of the century — the openings that let you into the first playable current.
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