If one asked two random scholars for a definition of magic, they would probably get five different answers. At its core, though, magic is pretty simple to understand – it is a process by which magical creatures and mages utilize mana to affect themselves and their surroundings. Most of the arguments stem from disagreements about how direct and conscious such mana utilization has to be in order to count as ‘magic’. Do the ‘impossible’ biologies of magical creatures and passive magical traits of some human bloodlines count as magic, even though there is no conscious shaping of mana? Should alchemy and other forms of magical artifice, which simply utilize magical materials and involve no actual mana shaping themselves, be classified as magic?

For many people, such questions are nothing more than pointless theorizing. For an average civilian, a mage is a very broad and fuzzy concept – a lot of them consider even products of mundane engineering, such as trains and guns, to be a form of magic. The fact that fancier versions of technology often include some form of magic in their construction doesn’t help in that regard. However, for people whose lives depend on magic, the questions are not entirely academical. Magic and people involved with it are extensively regulated in most places, subject to closer scrutiny and higher taxes, so many people would object bitterly to the idea they are mages or working with magic. On the other hand, mages have a high status in society, and are often incentivized and protected in various ways, so a lot of people fight hard for their right to be considered ‘real mages’.

Legal definitions aside, it is obvious that any explanation of magic is inextricably connected to an explanation of mana – the mysterious energy that provides the fuel and building blocks necessary for it to work.

Mana:

Mana is an invisible, intangible substance that powers magical abilities and phenomena. Every soul produces it to some extent, and massive quantities of it well up from the depths of the planet to inundate the underworld and large portions of the surface. In many ways, mana behaves as a strange type of gas, although one that can pass through and permeate solid objects.

Mana comes in two main types: personal (or attuned) mana and ambient (or raw) mana.

Personal Mana:

All beings with a soul have a pool of personal mana at their disposal. The size of this pool varies greatly between individuals of the same species, but it’s always there. Since this mana is attuned to the mind and body of the being producing it, it bends easily to its creator’s will. This makes personal mana innately more malleable and controllable than anything else a magic user might use to power their magic, as it does not resist the caster’s efforts to shape and wield it.

Mages refer to this pool of personal mana as their mana reserves. If any of these reserves are spent, they will gradually refill themselves on their own – souls generate mana ex nihilo at a rate proportional to the size of one’s mana reserves. In addition, it is possible to speed this process up by absorbing a steady trickle of ambient mana and assimilating it into the one’s mana reserves.

It takes anywhere between 30 minutes and 3 hours for a mage to regenerate their mana reserves from total zero to full if ambient mana levels are sufficiently plentiful, depending on their personal skill and willingness to risk mana poisoning. It takes about 9 hours to do the same if they’re in one of the rare ‘dead magic zones’ that have no ambient mana whatsoever. Most places have at least a little ambient mana floating around, however.

This is unaffected by the size of one’s mana reserves – those with higher reserves will simply regenerate more mana per minute.

Although higher levels of ambient mana are helpful in speeding up personal mana regeneration, beyond a certain point the individual’s ability to siphon ambient mana to regenerate their own will depend more on their ability to assimilate said foreign mana safely than actual mana availability. Generally, mana wells of rank 3 or higher are important only in the sense they allow progressively more mages to siphon progressively more mana without depleting the ambient mana reserves.

If separated from the soul it has been attuned to, personal mana will rapidly degrade into ambient mana – which seems to be the default form of mana when not attuned to anything. This makes attempts to create an external storage of personal mana doomed to failure. Regardless of the method used, the mana will un-attune itself in a matter of minutes.

Personal mana can be given to another, or be forcibly taken away from people and souls. Since this mana is already aligned with someone, it is difficult to shape and control. This is especially true if it was forcibly taken. The difficulty also depends on how similar the user and mana donor are in mind and body – creatures of two radically different species would find it almost impossible to use each other’s personal mana in any manner, for instance. For the most part, mages only use other people’s mana in ritual setups, where speed of spellcasting is not a concern and they can take steps to mitigate the additional shaping difficulty.

A soul bond, such as that between a familiar and caster, makes sharing mana easier. Frequent mana sharing between the same people will cause them to gradually get used to each other’s mana, likewise easing mana sharing… though only between those specific individuals. Some creatures and bloodlines can innately use other people’s mana with greater ease than normal.

Ambient Mana:

Mana doesn’t disappear on its own. Unless it is spent on magic use, any mana that is released into the environment will slowly disperse throughout the area it is in and linger there. This free-floating, ownerless mana suffusing the environment is called ambient mana.

Ambient mana is everywhere. Aside from a handful of rare (and mostly artificial) areas, most of the planetary surface has at least small amounts of ambient mana suffusing it. There is too much mana floating around for it to come from living beings, who are rarely in the habit of pointlessly venting their mana reserves into the area around them. Where, then, does all this ambient mana comes from?

The short answer is that it comes from underground. Beneath the surface of the world is an extensive network of tunnels and caverns known by many names, but most commonly as the Dungeon and the Underworld. The Dungeon is very rich in ambient mana, and the deeper one goes, the higher the concentration of ambient mana becomes. Something down there seems to be generating incomprehensibly huge amounts of mana, which then gradually wells up to the planet’s surface.

No one has ever descended deep enough into the Dungeon to find the source of all this ambient mana. Since the only other thing that produces mana are souls, most cultures have decided since ancient times that there must be something alive down there. Something so powerful that its soul produces all this mana to inundate the world with. For example, the Ikosian creation myth states that this something is the heart of the World Dragon, from whose body the entire world was fashioned. Ultimately, though, nobody knows the answer to this mystery, and it is unlikely it will be solved any time soon.

Although ambient mana is relatively abundant in most places, it cannot be used directly for spellcasting. Or more precisely, it is very unwise to do so. Ambient mana erodes and damages things that channel it, which makes it highly toxic to living beings. Even small amounts of it will cause people to sicken and become delirious for hours or days, and prolonged use will quickly result in permanent physical disabilities and incurable madness. Drawing too much of it at once will lead to the death of the user, usually via sudden body explosion or being cooked from the inside out.

Despite these dangers, ambient mana is still in widespread use. The simplest, as well as the most reckless form of this consists of outright ignoring the dangers in isolated occasions. This is certain to incapacitate the mage in question for quite some time afterwards, but if the situation is desperate enough, they might feel the price is worth it. Since overuse of this tactic can easily result in reasonably healthy but thoroughly insane mages (with all the dangers this implies) the practice of drawing upon ambient mana is usually categorically banned in most places. Most mages do it anyway if they are backed into a corner or think they’re about to die if they don’t, so in most cases the authorities turn a blind eye to such usage of ambient mana.

Toxicity aside, ambient mana does not resist being wielded. It is relatively easy to shape into effects, though not as much as one’s personal mana.

The second, and probably the most widely used method, is to utilize ambient mana to augment the regeneration of one’s mana reserves. This is done by slowly drawing upon ambient mana and assimilating it into existing mana reserves. In the past, this was a rare and ill-understood ability – it is only in the last 200 years or so that mages figured out a reliable and easy-to-learn method to attune ambient mana into one’s personal mana reserves. This was mostly done by closely studying magical creatures, who passively and unconsciously use this method to ‘feed’ upon ambient mana. Even today, most magical creatures are still better at assimilating ambient mana than the average human mage.

Finally, it is possible to sidestep the toxicity of ambient mana by anchoring persistent spells upon inanimate objects and instructing them to draw upon ambient mana to power themselves. This is the method used in construction of some magical items and warding schemes. Although, technically speaking, this doesn’t negate the destructive tendencies of raw mana usage, a chunk of stone or a block of wood are a lot less delicate than living beings. They cannot sicken, and have no minds that can be driven insane. However, if too much ambient mana is channeled through an object too inadequate to bear the pressure, it can still break, burn or melt. This ambient mana overload is not necessarily an all-or-nothing deal, and it’s perfectly possible for a spell to quietly erode the structural integrity of its anchor over a long period of time until the damage becomes too much and it collapses under the weight of its accumulated flaws. Poorly made magic items can be quite dangerous for the wielder, and people trying to sell them for a living are often subject to official quality controls of a sort.

Higher order undead, such as liches and vampires, do not have living bodies but are capable of spellcasting nonetheless. At first glance, it may seem that they would be able to use ambient mana a lot more freely as a result. To an extent, this is true – they certainly won’t be incapacitated by sickness in the aftermath of such use. However, in order to retain their sapience, such undead need to possess a sort of magical brain to think with… and that brain is every bit as vulnerable to insanity as biological ones. Undead can’t get sick, but that just means they can get insane without being physically crippled – most people, even undead people, agree this is not a good thing.