Lab · browser target
Why the dinosaur gets faster — play the recovered rule
Offline Chromium’s T-Rex runner accelerates as you run. REA can read the loaded script from a public HTTP edition, recover the constants, and help you rebuild a tiny game with a speed control. This page hosts that teaching rebuild on rea.run (static Pages) — play the recovered rule, then follow the operator steps below.
Enable JavaScript to play. You can still read the rule and open the source and license notes below.
Original rule: start at 6, then increase toward 13.
Recovered settings (verifiable)
| Symbol | Value | Meaning |
|---|---|---|
SPEED | 6 | Starting speed |
ACCELERATION | 0.001 | Added each eligible update |
MAX_SPEED check | 13 | Stop accelerating once at/above this threshold |
| Logic rate (this demo) | 60 updates/s | Fixed simulation tick; drawing is separate |
if (this.currentSpeed < this.config.MAX_SPEED) {
this.currentSpeed += this.config.ACCELERATION;
}
Inspected target: wayou’s Chromium-derived browser edition
(HTTP). Do not confuse with chrome://dino unless your session documents that URL.
What is new vs reconstructed
| Piece | Source |
|---|---|
| Acceleration rule (6 / 0.001 / 13) | Reconstructed from inspected index.js |
| Canvas drawing, jump physics, cactus collision, obstacle spacing | New teaching implementation on this site |
| Speed slider + auto-accelerate checkbox | Teaching controls (not in the original game UI) |
Checkpoint table (controlled replay)
A controlled original-game check (obstacles and auto-scheduling disabled) recorded these speeds after N collision-free updates. Click to replay the same rule in the browser:
| Updates | Reference | This page |
|---|---|---|
| 0 | 6.000 | — |
| 1,000 | 7.000 | — |
| 4,000 | 10.000 | — |
| 10,000 | 13.001 | — |
Note: after 10,000 updates the float lands at 13.001 when rounded to three decimals — the
threshold check uses < 13, so one more increment can pass 13 before the branch stops adding.
Operator steps (authorized public page)
- Pin
rea-agentsdeliberately (teaching pin elsewhere often 6.5.0; match your session). - Launch Chrome with a remote-debugging port and open the public t-rex-runner URL (templates on /docs/install-demo/).
- Ask the agent to
list_browser_targets, theninspect_web_pagewith script sources, and read loadedindex.js. - Demand the start speed, increment, and cap check with citations — rules only before any rebuild.
- Rebuild a one-file game with a slider; verify the four checkpoints above.
Use REA to inspect this dinosaur game. Why does it get faster?
Show the speed rule, then build a small version with an adjustable speed.License & attribution
- Selected speed-rule excerpts: Chromium Authors, BSD-style terms — /licenses/dinosaur-bsd.txt.
- Standalone extraction commonly cited: wayou/t-rex-runner.
- This mini-game’s graphics / jump / collision are teaching code for rea.run; redistribute with attribution for the rule.
Related
| Resource | Link |
|---|---|
| Lab hub | /lab/ |
| Calculator % lab | /lab/calculator-percent/ |
| Codex install demo | /docs/install-demo/ |
| DX-Ball Evidence | /showcase/dx-ball/ |
| Chinese twin | /zh/lab/dino-speed/ |