The ambient arcane energy field, more colloquially called magic, is an arcane force omnipresent throughout the Aequor Arcanus.
The ambient arcane energy field is an abstract representation of the total quantity of magical energy present in every point in spacetime. Magical energy can be thought of as a property of matter, comparable to properties such as mass or electrical charge, which describe an entity's relation to gravitational or electromagnetic fields. The main factor that distinguishes magic from other physical properties is that the intrinsic quality that determines an entity's magic originates from outside of the physical world. The Aequor is a term used by Corvidan arcane theorists to describe the entirety of the physically-observable universe: matter, energy, space, time, etc. The quantity of magical energy present in any given entity within the Aequor cannot be adequately explained by any measurable physical properties of the Aequor. As such, the only reasonable explanation is that the entities that produce the arcane energy field exist outside the Aequor. The theoretical spaces from which the arcane energy field originates are referred to as extraplanar realms; they can be directly observed and accessed only through magical means such as spellcasting.
It is possible to deduce the existence of forces like gravity and electromagnetism by observing their effects, such as falling objects or a spinning compass, without any understanding of the theoretical physics that explains their behavior. In a similar fashion, most Corvidans know magic only through its effects on the physical world, without comprehending the arcane field or extraplanar forces that cause those effects. In a layperson's understanding, magic is an energy that exists everywhere to varying degrees. Mages can draw from that energy to cast spells.
It is generally understood that mages are capable of manipulating magic directly because of an intrinsic quality called life energy, but laypersons and arcane theorists alike have only a cursory understanding of exactly what life energy is. The complicating factor in studying life energy is that tampering with it in any way tends to kill the test subject, even when the subject had no previous health concerns. Life energy exists within all living sentient beings, and it is believed that consciousness is essential to its presence in a given entity. Highly intelligent animals such as cetaceans and corvids have been shown to possess a limited capacity to manipulate magic, although not to the extent of fully-sentient beings.
Under normal conditions, magic is imperceptible except through its effects. However, the ambient arcane energy field itself can be sensed through various means: with spellcasting, as a side effect of chaos, or even as an ability of innate mages. Persons capable of perceiving magic typically describe it as a barely-audible low hum, a vibration in their body, or a shimmering mirage.