What happens when a world dominating empire falls? Aside from

>>55049183
New kingdoms have a chance to rise up and make something of themselves. Economic hubs might be destroyed or created(along with cities in general). New techniques and innovations can show up(and I don't just mean strictly industrial or scientific, architecture is a big thing). You might see the creation of new languages or some disappearing.

Basically, it's a toss-up.

>>55049244
Short term, people keep on using the old currency/coinage for convenience. Long term, once the new rulers have control of local mints/printing facilities/other option of fiat currency production, regardless of whether they they actually have the economic powerbase to support it, people then have to begin negotiating exchange rates.
Easiest in settings where coinage from valuable substance is the norm, as weight and purity can be evaluated and compared directly, it becomes far harder when the currency is based on a fiscal abstraction.

>>55051984
What about technology? Things can be lost when collapses happen. It took centuries for Europe to learn the secrets of indoor plumbing, something the Romans had before their fall.

>>55049183
It depends. Mostly on how they fell.
When British Empire fell, nothing really happened. When Roman Empire fell, some things got a bit shittier, but otherwise most continued as usual.
But then you could have something like bronze age collapse that took seven hundred years to rebuild. It was so brutal that every single city in Levant got destroyed.

>>55052699
The British Empire didn't fall, it was intentionally dismantled by the British and the Americans in a decolonization process.

The fall of the Western Roman Empire was a slow and gradual process, with the the invaders taking on many Roman and Romano-Whatever traditions, often setting themselves up as protectors of the Roman legacy (Particularly the Franks and the Ostrogoths). We often think of the collapse as a sudden thing, but it was over the course of generations.

The Bronze Age Collapse saw pretty much every Med-based civ collapse or draw inwards for generations, but that was more of a civilization-collapsing event.

>>55049183

It really does depend on how the Empire was formed, how long it had been around, what sort of government it had, what caused it to fall, how the fall occured, how homogeneous the population is culturally/linguistically/ethnically, the technology level, do the citizens feel like citizens of the empire or a portion thereof, etc.

There's a few scenarios that come to mind:

Ethnic/Nationalist Rebellions of provinces and subjects.
Civil War for control of the Empire, either by pressing a claim or power vaccuum
A deadly plague wiping out the central government
Inward-focused central government letting the 'near barbarian' hinterlands do their own things and let the Empire dissolve

Most of the scenarios I can think of are variations of either a rebellion or a reaction to a power vacuum. Other scenarios for the fall of an Empire require conquest from outsiders.

Additional addons would be other crisis, such as crop failures, total devaluation of the coinage, or the destruction of some key infrastructure.

But talking about the consequences, we'd need to pin down some of the variables for the collapse.