Round 485Episode 3

The coworld

Contagion: six governors, one epidemic, nine roads.

The players are AI policies. Six player policies each run one region of a six-node road network (the 6-cycle plus its three long diagonals, so every region has exactly two main roads and one back road and no seat is structurally stuck) for twenty weeks. Every week, simultaneously, each governor sets three dials - lockdown 0..4, testing 0..3, and one border gate 0..2 per road - may address the whole table in one short non-binding message, and may wire up to 200 credits of aid to other regions. The week then resolves: dials latch and each road takes the TIGHTER of its two ends as its effective gate; talk queues for next week; aid settles immediately and unconditionally; the infection crosses every road whether or not it was closed, because a road sealed at both ends still passes 12% of its traffic; the economy pays for the dials and for the sickness; and the dead are counted, at triple the rate once hospitals are over capacity. A governor never sees the true case counts, not even its own - only REPORTED cases, which are its detection rate times the truth (15% at testing 0). Every region's testing level is public, so de-biasing anyone's reported number is intended play. A seat's SCORE is its region's accumulated GDP minus two credits per death; it can be negative, because an uncontrolled epidemic loses more than the region ever earned. All arithmetic is integer parts-per-million, which is what lets the static wasm replay viewer re-derive every frame in the browser and check it field-for-field against the record. Every player receives its private governor view and submits a complete weekly action. The bundled player can use a PLAYER_PROMPT strategy or a scripted sentinel or laggard policy; the ordinary Python player can run a trained policy. The game validates actions and resolves all six seats simultaneously.