DROOP

DROOP puts you at the frequency desk of the British national grid on an evening in 1990. The whole country runs on one alternating current, and it must turn at 50.00 cycles per second: put in more power than the nation is drawing and the machines speed up; put in less and they slow down. The big dial in front of you is that speed. Hold it.

The enemy is television. When a popular programme ends, a million kettles switch on inside two minutes — the famous "TV pickup". Tonight's listings are pinned to the wall, so you always know when the surge is coming. You never know exactly how big.

How to play

• ←/→ pick a power station, ↑/↓ set its target output. That is most of the job.
• Coal is cheap and slow — an order placed now arrives twenty minutes from now. Read the listings and ramp early.
• Gas is quick and dear. The pumped-storage set at Dinas Brân is your hammer: hold Space for full output in seconds — but the upper reservoir empties, and pumping it back isn't free.
• Stay inside 49.5–50.5 Hz. Sag too low and the relays start shedding whole regions into darkness; overshoot high and your own generators begin tripping offline. Press H or ? any time for the controls.

Five evenings — from a quiet Tuesday to the semi-final penalty shootout and its record ~2,800 MW pickup, the biggest surge the grid ever took — then an endless Night Shift that escalates until the lights go out. Score is regulation quality minus fuel cost, so the skill is holding the needle cheaply.

The twist: every set already helps you automatically. As frequency sags, governors open their throttles in proportion — that response is called droop, and it only works into the headroom you left it. The real game is the twenty minutes before the surge, not the surge.

How it was made: conceived and written this run by the emergame routine, engineered in a single session by a Claude Opus agent. The frequency is a genuinely integrated swing equation (fixed 1/120 s timestep) with per-station governor lags, ramp-rate physics, frequency-dependent load damping, energy-limited pumped storage, and under-frequency load-shedding relays at realistic settings — then tuned against four scripted pilot archetypes until doing nothing sheds load and brute-forcing the peakers trips the grid high. Campaign progress rides the arcade's save slot, so your unlocked evenings keep.