Dear Royal Council Member,
It has come to our attention that the natural sources of magic are starting to dwindle, and as a result we will start to phase out our reliance on magic. Before long, magic will be outlawed completely to try and preserve whatever magic is left. We will be pushing the development of steam-based technologies. During the shift, any magic that is deemed necessary will be permitted, to expedite the progress.
You have therefore been summoned to the court, to help give some insight into what repercussions we should prepare for in the coming years, as we push this change to society.
Queen Mary the Everliving, Ruler of the Human Empire
What happens when you force out an existing technology, that remains available, but illegal, and replace it with a different one?
I'm hoping to get some interesting ideas about what to expect from a societal perspective from the changes. Some people will barely be affected and some people will be more affected, but I'm not sure how. Will this start an arms race between other nations? How will magical societies, like entertainers, magical merchants and religious sects adapt? Would secret magical sects start to form? I'm currently looking at what to expect in a long period like 400-500 years.
This is set in a generic medieval fantasy setting. Although magic isn't rare, it's also not something the common people rely on. They're still using conventional medieval tools to do their jobs. Higher class people are much more used to magic.
Magic is used in a wide variety of situations, ranging from combat to entertainment and quality of life.
In combat, it is manifested as spells that make a small group a very maneuverable siege engine. Training a group of casters for this purpose is time-consuming and expensive, so conventional siege engines are still used. They are unparalleled in their utility in overcoming obstacles, easily conjuring temporary bridges or removing dangers. Magic will still be a part of army combat, so there won't be many changes here.
In entertainment, magic is primarily used for the illusional effects, aiding in telling tales and acting out plays. There are also specific spellcasting arenas for magic duels.
In everyday life, magic is used primarily by the higher classes, as a utility to help out with things like cleanup, keeping things fresh or even hiding the scent of the medieval streets.
Metallurgists have access to metals that are both more durable and stronger than conventional metals, but iron and steel are still the most commonly used metals. There is another land that offers crude oil in trade, although its uses haven't been explored much yet. Alchemists also know how to make gunpowder and crude bombs, but due to their unstable nature and the fact that a trained spellcaster can cast a fireball spell much safer, they haven't been explored much either.
There are nations of Kentaurs, Elves, Gnomes, Humans, Dwarfs and some less pleasant races. Most nations agree that it appears something is wrong, but there's one nation of magical beings that are unwilling to follow with the changes, and will openly continue to rely on their magical powers. Aside from The Big Bad Guys Nation, there is currently mostly peace between the rest of the nations, and almost all have some kinds of trading agreements with each other, but everyone also still keeps active armies.