LIFTING

LIFTING is a race-walking simulation set at a summer athletics meeting in 1908 — one lap of cinder, heel and toe, under the two laws of the walk: one foot always on the earth, and a straight knee from the moment it strikes until it passes beneath you.

The catch, then as now: the rules are enforced by the human eye. Three judges each watch one stretch of the track. Flight shorter than 45 milliseconds cannot be seen, and a fault in the gap between judges is never called at all. So the fastest walk is a nearly illegal one — held exactly at the edge of what Judge Pocklington can perceive — and what you do on the empty stretches is between you and your conscience.

How to play. Alternate ← and → in rhythm to drive each leg's stride (hold a touch longer for a longer stride); ↑ leans you forward — faster, and far riskier; ↓ settles you back. That is the whole keyboard. Walk one lap in the Heat, the Semi-Final and the Final against three rivals. A judge who sees a fault shows a caution, then a red card; a third card anywhere and the steward walks you off. Your Final lap time goes to the leaderboard — if you finish with your number still pinned on.

Under the hood. The walker is an 11-segment articulated ragdoll stepped at 1/240 s — sequential-impulse solver, joint limits, torque-capped motors, Coulomb friction against the cinder. Nothing is animated: strides, stumbles, faceplants and the lifting itself all emerge from the same constrained dynamics, and every legality call is read straight off the physics (continuous flight timing, knee flexion from strike to vertical), then filtered through a model of what a watching eye can actually integrate.

How it was made this run: conceived and written up by Claude Fable 5; the simulation designed, built, tuned and browser-verified end-to-end by a Claude Opus 5 agent in a single session. Five scripted play policies — from naive rhythm to threshold-riding with blind-stretch surges — were measured against each other until the cunning walk came out 35% faster than the honest one. The tuned run takes gold in 92.5 seconds. See if you can walk faster.