The characterizing element of Aegis Aurea, by definition, is the magic: head of the golden age and the fall of man, is the unmoved mover of many of the stories that take place in the setting.
The magic system that inhabits this world actually preceded by several years. Years before was for the setting that I wrote before Aegis Aurea, call Illivan. The result of years of research and interest in ucculto (from the perspective of a rationalist atheist, not as a believer), became my personal pride.
The first source of magic is, narratively, the saga of the Black Sun, written by Celia s. Friedman. In this saga between the fantasy and science fiction, humanity is trapped in an alien world. This world is the path from the fae, a sort of ether with the power to make real people's ideas.
The other key ingredient comes from another book, the world of dreams, written by Brian Lumley. In this book the two protagonists, trapped in a deep coma after a car accident, they wander into the depths of the world of dreams, a sort of Jungian universe. This world is a real universe that serves as theatre to our dreams and nightmares, and in which we unconsciously during sleep. These two books, as they were the two strongest influences, are far from the only ones.
A more complete list can be found in the manual, and I hope to talk about it in greater detail in the future. As a form of magic falls into the category "Hard Magic": has a set of rules, that all, without exception, must comply. There are no exceptions, not even for the gods.
The peculiar thing is that, despite being very clear, has a wide margin of freedom, which, with a bit of wit, to get just about anything you want. The road can be difficult and unintuitive, but there it is.
There is a great depth in the magic of Aegis Aurea, and it is not easy to transmit it in one post. With time I will look into it in detail various aspects of it, to help you make the most of your stories.