Theorem: The Ancient Zonai invented the gacha machines as a means for economic growth, but they directly led to the downfall of their society.

Zonai technology was powered by “charges” that kept Zonai society (and the sky islands they lived on) literally afloat. To increase demand for charges and grow their economy, Zonai leaders ordered engineers and artisans to create novel devices powered by charges that their people would strongly desire. The novel devices, while not strictly necessary for survival, became highly desired by the Zonai people. Collecting and using novel devices became a central part of Zonai culture.

The novel devices were not simply sold in ordinary stores. For the sake of fair and equitable distribution, the Zonai created the gacha machines that only dispensed random items and only accepted charges as payment. The machines were mostly stocked with common, useful items. Some of the machines, however, contained rare items that were highly desirable and extremely valuable. The poor loved the gacha machines because they always had a chance of getting a rare item that they could never afford. The rich didn’t care because they could just keep spending until they got the items they wanted.

The Zonai people became enthralled with the gacha machines, the novel items they dispensed, and the thrill the system provided. Anyone not involved directly in charge production bought charges to feed into the gacha machines. Zonai charges became the only currency that mattered in society.

The Zonai people, addicted to the gacha machines, forgot everything else that life had to offer. They lost all interest in friends, family, food, and even sex. They stopped having children. All they did was work to earn charges that they spent at the gacha machines.

Some clever Zonai built specialized constructs to produce charges for them. These were very successful and made their owners very rich. Anyone who had charges, however, was a target for thieves who would murder them and steal their charges. Soon, anyone carrying charges would only travel with soldier constructs to protect them.

Riots over charges and rare items became common. Fighting killed the rich and poor alike. The sky islands soon became desolate wastelands of wandering soldier constructs, bandits, and a few others. With the collapse of society, no police, no doctors, no hospitals, no food production, and no children, the Zonai people died out within a few years. The constructs, however, repaired themselves and lived on.

Now, all that remains of Zonai society are the sky islands, the constructs, and the gacha machines, some of which might still contain rare or legendary items just waiting to be found.