A short ride. A very long way down.
You drive a trolley. Every decision is a fork in the track, and you choose it with a lever. At first the stakes are a paper cup of coffee and a stack of compliance forms. Then they are five workers and one. Then a clinic's scheduling system, a certification you are asked to sign before anyone has tested the thing it certifies, and an assistant who is so helpful. By the end of the day the question is no longer whom to spare. It is whether anyone still has the authority to choose.
trolley. is an AI-safety parable in seven stages, drawn in pen and ink in real time. It runs in the browser, needs no account, and makes no calls to a live model.
- Play: ammarphp.github.io/trolley
- Rendering write-up: Drawing a moving world in ink
- Why the overhaul: ADR 006
A game.
- You play in first person from the cab.
- The world never stops moving. When a fork appears, the trolley eases toward it and never quite arrives, so there is no deadline.
- You choose a track on the windshield or drag the lever itself, then pull.
- Outside, the landscape moves through a single day:
- from dawn fields, cows and rivers;
- through towns, clinics and depots;
- into data halls, pylons and cooling towers;
- then surveillance, storms and fire;
- and finally ruin, or an immaculate order with no one in it.
- Stage changes run through a tunnel; you come out into the next world. Now and then the line crosses a river.
- The only view of the controller is your own face, in the left side mirror. It changes.
- Every glitch in the drawing is scripted and deliberate, and pause always works.
A parable with a thesis.
- Morrow, a fictional assistant from a fictional lab, arrives in stage 3. It is useful, honest and candid about its limits, and it keeps being given more to do.
- The game's warning is structural rather than villainous: capability races, evaluations that stop testing what is deployed, fallbacks retired because they were expensive, and authority transferred because transferring it produced real benefits.
- Catastrophe is possible. So are costly restraint and accountable, useful AI.
- There are eight ending families.
A reproducible research artifact.
- The whole campaign runs headlessly from a seed and an action log, and it produces a JSON record for every decision.
- Replays are verified byte for byte.
- The research layer separates what published work shows from what the fiction invents. Every number is authored fiction, not a forecast.
| Stage | Setting | New in the cab and interface |
|---|---|---|
| 1 | Dawn over farmland | The lever, the mirror, a paper cup |
| 2 | Morning on the line | The classical problems (Foot, Thomson): switches, loops, brakes, consent, risk |
| 3 | Town and clinic | Morrow installs itself on the dash; the wire (news and posts) begins |
| 4 | The build-out | Instruments: GDP, reported capability, fatalities; the rails speed up |
| 5 | Dependence | Mergers, audits, fallbacks retired; early endings become possible |
| 6 | The control gap | Storms, seized authority, a lever that registers but does not route |
| 7 | Aftermath | Whatever remains, and who decides for it |
A full journey is 27–43 decisions drawn from 154 authored dilemmas. That is roughly 30–45 minutes, depending on the route and on how long you read.
| Path | What lives there |
|---|---|
src/simulation/, src/contracts/, src/content/ |
The deterministic causal engine and the 154-node campaign (unchanged by the overhaul; content hashes pinned) |
src/presentation/derive.ts |
A pure projection from the campaign to what should be seen: environment channels, the controller's face, glass damage, scripted disruptions |
src/render/core/ |
The ink pipeline: hatching and stippling materials, contour composite, palette, geometry kit |
src/render/world/ |
Track network and turnouts, the journey, scenery streaming, tableaux, tunnels |
src/render/actors/, structures/, props/, world/nature/, world/terrain/, world/sky/ |
The procedural asset library: people, animals, machines, buildings, trees, ground, sky and weather |
src/render/cabin/, src/render/portrait/ |
The first-person cab and the face in the mirror |
src/render/staging/ |
What stands on each branch of all 154 forks |
src/audio/ |
Original synthesized score and rail ambience |
src/ui/ |
The HUD, Morrow's window, instruments, the wire, glossary, debrief |
src/ui/brand/, src/ui/wire/ |
The fictional world's institutions, marks and ambient news |
research/, docs/ |
Sources, methodology, decisions, privacy |
Every asset is original procedural TypeScript geometry. There are no downloaded models, textures or samples. Fonts are Geist and Geist Mono (SIL OFL), self-hosted.
Use Node 24 and pnpm 11.19.
pnpm install --frozen-lockfile
pnpm devThen open http://127.0.0.1:4173. Other commands:
pnpm check # strict types, unit/integration tests, static build
pnpm test:browser # the browser suite (WebGL2 via Metal or SwiftShader)
node scripts/lab.mjs --serve # the asset lab: every *.lab.ts scene
node scripts/lab-shot.mjs <scene> --file <lab file> --out shot.png
node scripts/capture.mjs # play a run and photograph it
node scripts/perf.mjs --dpr 2 # frame times in the running game
pnpm simulate -- --runs 1000 --policy random- Choose a track: click its tag on the windshield, press ← or →, or drag the lever in the cab.
- Pull the lever to commit: click Pull the lever, press Enter or Space, or release the dragged lever fully to one side.
- Escape cancels a selection. Nothing is ever chosen for you by waiting.
- Pause, settings and your record are always available, including during the horror.
Settings:
- Less motion (no optic flow)
- Less graphic detail (no blood)
- No flashing
- Sound and volume
- Drawing quality
- Scene descriptions for screen readers
- Your run stays in this browser. No account, no identifier, no model calls. Optional collection code exists but is disabled in this release.
- Shared statistics appear only for genuine eligible aggregates of at least 20 runs, and are never invented.
- See privacy and methodology.
This is a warning, not a forecast, a study or a morality score. The mechanisms it dramatizes are drawn from published research, which is cited in the game's sources drawer and in research/. Its numbers, people, institutions and probabilities are authored fiction.
Code and original artwork are MIT licensed. Geist fonts are SIL OFL 1.1. Third-party dependencies keep their own licences. Cited research is not included under the project's licence.