Anyone with the ‘gift’ of magic may use it. It is most commonly a hereditary thing that can be inherited from family. Elves and other particularly magical races are near guaranteed to have it though.
Humans however, have it mainly through intermingling with other races as humans did not originally have it in their bloodlines.
Exceptional circumstances like pacts with dragons and other powerful entities have also been known to bestow the capacity to use magic. There are also powerful magical artifacts that can grant people the ability to wield magic through them as well.
In general, Magics main limiter in usage is tied to the users personal ability, and their degree of creativity, barring those, raw power can still make almost anything happen.
As a general rule, if you do not have the gift, you can’t even see magic under normal circumstances. Though the most obvious forms that might project light or interact directly with the environment are clearly visible. In this case what they see is the effect of the spell, and not the magic itself.
People with the gift however perceive magic as a tangible thing in the world. All of their senses can detect it in some form, and most mages have a personal signature or flair that immediately identifies their magic.
Some people have also been found to have certain types of disabilities like being incapable of recovering the mana without aid. This can occur even in those without the gift of magic.
Having the ability to use magic also confers a variable amount of resistance to it, this correlates with how much magic a person has been exposed to… There is such thing as too much magic though, as it can make it very difficult for the person to cast spells at all. This resistance is not permanent, and can vary over the course of a person's life depending on their exposure to magic. This build up of magic resistance is significantly lower for people who do not have the gift, as they are not nearly as sensitive to magic. Some cultures have been known to purposefully expose people to magic in the hopes of awakening the gift of magic within them.
There are several disciplines that attempt to create a unified system by which magic can be controlled. Those include, but are not limited to the following…
Shamanism, which is a discipline of magic used to ask spirits for their aid in casting, or directly the casting the magic. Depending on the power of the spirits and number, a powerful shaman can employ magic far more powerful than nearly any other field of magic. The methods by which this occurs is primarily in the form of an exchange of mana between the user and the spirits, as spirits are made almost entirely of magic. They need it to survive. This ancient magic is borne of pacts in the distant past between mortals and the spirit realm. One of the main requirements for using this magic is that it is absolutely crucial that the shaman be able to speak in order to communicate with the spirits. The preferred language is elvish, though many spirits know other languages to a varying degree. More powerful spirits do not care about the limits of language. Spirits are by and large uncomprehending of mortals. More on that another time.
If you discover this tale on Amazon, be aware that it has been stolen. Please report the violation.
Wild Magic is usually the hallmark of an untrained mage, this magic can cause powerful effects through the expenditure of vast amounts of mana. It is extremely wasteful by comparison to other means of manipulating spells. It’s most powerful effects are extremely potent, but also very fleeting due to the lack of structure. Things that would be otherwise impossible with conventional magic are rendered barely plausible by raw power.
Studious casting on the other hand uses and requires Spell Books and intense study. It is the classical idea of a mage and the most common one.
Divine Casting or sometimes called pact magic, and by still others summoning. It is closely related to shamanism, but is not quite as focused. It is the act of manipulating magic through the assistance of prayer and actualizing the power of a deity or other powerful being. The magic consumed is primarily used as a tithe and the means to establish contact. It is otherwise believed that most deities are capable of a discipline of magic that is kept exclusive amongst only beings of extreme power and importance. The actual effect here is that the deity allows the caster to borrow some of their power and use of magic that is not normally possible to be wielded by mortals. In order to borrow such power a supernatural being usually exacts a price for their power in the form of a pact, quest or service.
Empathetic Magic - The only form of magic that can be used without the gift. This magic is much harder to quantify because it is much more passive and its effects are far more subtle. This magic is how artifacts can be spontaneously created by powerful emotion, and events in the world… The underlying “How” of this magic is that the world is mirrored by every soul in parallel. Souls interact with each other in subtle ways to cause powerful permanent effects grounded in real and perceived events.
The basic idea is that if a large number of people feel a particular emotion it might be enough to cause magic to oblige that feeling, either in the form of spontaneuously manifesting a magical item or simply casting an actual spell. Its more a unified subconcious desire by souls instead of individuals.
In addition to that, the idea is that magic is a wild force of nature that is in tune with every living thing, whether or not they actually have the capacity to consciously interact with it (The gift of magic).
Similarly historic events that have lasting effects on the psychee of an entire culture, or even superstitions, might cause magic to oblige by making it real. In reality its the collective will of many people. In the same way, deities may even be created by belief in this way.
In every single discipline of magic, there are several basic elements. These include: Soul, Force, Matter and Void. All other branches of magic are sub elements from these basic ideals.