Graescence is the essence of life. It is the lifeblood of society, the fuel for all technology, the bane of the classes, and power incarnate.

In other words, nobody actually knows what it is.

Like gravity, it is a force that exists without explanation, though it's easy enough to describe what it does. Just as gravity's inexorable pull drags everything within its domain toward itself, graescence has various effects easily quantified and measured.

But what is it? No one knows.

Graescence only ever comes from living things. Period. Never has there been an exception. Graescence can only be controlled by substances that come from living things. Most notably, the Elderin tree, which is the core of all technology within the empire.

It is not a substance; it cannot be poured into any container. But it can be contained, trapped in an endless loop until ready for use, theoretically. In practice, there is no perfect loop. All capacitors leak.

It is usually described by wave theory, a mathematical language based on the motion of waves. Wave theory describes the interaction of waves, and while graescence conforms to this mathematical formula, it only does so in limited circumstances. In other cases, graescence acts as though it is an addition of simple waves, where the resonant peaks add to each other in a consistent manner.

Yet in other situations, graescence appears to act as though 1 + 1 is 3, or 10, or even 100. However, this only happens when graescence interacts with itself, which has only ever occurred when something living is manipulating it. There are no known instances of using tech to achieve this effect.

This exponential power increase is believed to be caused by graescence interacting with itself in other dimensions, effectively "pulling" energy in from those other dimensions. How that works, no one knows, but it's the only way the math makes sense.

This exponential increase in power is invariably coupled with an exponential increase in instability, to the point where a four dimensional graescent field is more likely to explode than do anything useful. Note: when speaking of dimensional graescence, it is assumed that first "dimension" of graescence is the "three" we live in. This means a three dimensional field is interacting with two dimensions outside of our own. Given that only the living can do this, attempts to use this effect as a weapon are generally short lived.

Most people generate somewhere between one to two dimensional graescence, where the second dimension comes from normal interactions of graescence within the body. Every person has a "pattern" of graescent flows within them, rather like a finger print. It's this pattern that largely dictates the amount of graescence that person can emit.

It is technically possible to alter one's internal graescent patterns to increase the amount of graescence produced. This is extremely dangerous, and the vast majority of those who try end up literally tearing their own body apart. Although the normal lay person would have no idea where to start, those who practice manipulating their graescence, like shapers, are strongly discouraged from applying their practice to their own body.

There are aberrations, the most notable of which are Godlings. For whatever reason, these individuals naturally interact with graescence on more than two dimensions, causing them to be capable of producing extreme amounts of it. They considered highly volatile and dangerous, and are actively hunted down by the empire and killed. This is, arguably, one of the primary purpose of the Inquisitors.

There are also those with Traits, which are a wide variety of supernatural "abilities" ranging from useless to profound and even dangerous. A trait may allow an individual to power graetech from afar rather than touching it, though usually at a loss of efficiency. Some traits allow people to "pull" small graescent objects toward them, or "push" them away, neat party tricks but rather useless otherwise. There are thousands of traits with endless variations, all of which are catalogued and tracked by the government.

The only compendium to come close to accurately describing graescence is an ancient text called "The Gravitica". These texts are written with an extraordinary number of symbols, commonly called runes, numbering in the tens of thousands. These runes have very specific interactions with each other that mimic the mathematical relationship described by wave theory. However, unlike wave theory, these interactions occur across any number of dimensions, which are represented by a separate set of runic subscripts beneath each primary rune. Because of the exponential complexity inherent in the Gravitica, one can spend a lifetime studying only a small subset of it.

The Gravitica is technically banned by the empire, although enforcement is lax. It is believed to have been central in the creation of old world relics, but the how has been long lost to history—all current tech uses standard wave theory. Not many know it exists, and its sheer complexity would discourage most from studying it. All known copies are owned by Royals, and usually as collector pieces.