whatA stadium ring of spectators who can do exactly three things: sit, leap, and slump back winded. Each fan watches mostly the neighbours on one side -- attention in a stadium is asymmetric -- leaps when enough of them are up, and cannot leap again until recovered.

whyThe claim has three floors, all on one slider. Timid crowds: a launched wave dies within a few seats -- the ledger prints how far it got. Willing crowds: the wave travels ONE direction and laps the bowl forever, speed measured in seats per second. High spirits: the same click launches BOTH directions, and the two counter-waves meet head-on at the far side and annihilate -- excitable waves do not pass through each other, they eat each other's fuel; the front census logs every such cancellation. Click anywhere on the ring to start one.

howThree states with fixed leap and recovery times; a resting fan integrates the leap amplitude of neighbours out to four seats, weighted by distance and discounted 0.35 from the unfavoured side, and leaps past a fixed threshold scaled by the mood slider. Everything deterministic; the automatic story cycles timid, willing, and exuberant moods, launching from seeded seats.