There were only fifty-seven Basic Runes in total.
When humanity first mastered supernatural abilities, every spell was a combination of those fifty-seven runes.
Every subsequent level of higher-order runes was more powerful and more specialized than the one before it, and naturally, each level contained more runes. Every higher-order rune also bore traces of a rune from the level below. In other words, it had been developed, refined, and strengthened from one of those earlier runes.
There were already more than five hundred First-Level Runes.
Nearly all Basic Runes and First-Level Runes had been discovered, unless the world gave birth to new ones.
They were also used worldwide. There were almost no runes known only to a particular country or organization. Outside a few extremely underdeveloped regions, even someone born in a small country could learn them.
There were several thousand Second-Level Runes.
The prevailing belief was that all Second-Level Runes had been discovered too. Unlike Basic Runes and First-Level Runes, however, the major powers had agreements not to let a tiny number of Second-Level Runes spread beyond their borders. Not everyone could access these restricted runes.
The restrictions were not especially strict, though.
In Yi Nation, you might need to work in a particular field and reach a certain rank to access them. Otherwise, you needed special means: perhaps a group of willful teachers who paid no mind to National Policy, or a purchase on the Deep Web.
Second-Level Runes were still what most experts outside official institutions used.
Restrictions on Third-Level Runes were much tighter.
Because of their complexity and power, the world's major powers kept searching for new Third-Level Runes. They also tightly controlled some newly discovered runes that had not yet spread and held special significance or value, preventing them from leaking out.
So even all