Magic

Source

The source of magic is innate and is known as a person's Ardency. Every person in the universe has the ability to cast magic, but most aren't able to tap into that part of their energy. It comes from a combination of their spirit (abdomen), their intellect (head) and their empathy (chest).
A low-level magic user (a.k.a. Spellcaster) will use only one of these three sources. Only strong magic users (a.k.a. Adept) are able to combine all three.

Spells cast only with their spirit are controllable but unsophisticated.

Spells cast only with their intellect are complex but lack energy.

Spells cast only with their empathy are energetic but unpredictable.

Rules

Abilities

Drawing on Ardency is all about the use of a person's energy to make changes to energy which exists within the physical world around them.

Ardency draws on elements of a person's energy to affect the energy around them

The energy could be used to create a physical object or destroy an existing one (although the energy from the destroyed object would have to go somewhere). It could be used for the creation, destruction or manipulation of sound, light or heat.
It could be used to work with electrical, magnetic or chemical energies too, although this is far less common and relies on a combination of elements, often a high level of intellect, in the Ardency which often dulls one of the other two elements. It could also be used to affect time which is a nebulous form of energy, difficult to control and requires a large reserve of Ardency.

Imbuing Magic

It is possible to imbue inanimate objects with magic drawn from the Ardency. This takes a lot of time and concentration and the energy can dissipate or warp over time. Only someone capable of tapping into all three elements of the Ardency (an Adept) is able to do this.

Read More About Types of Energy

Energy	Impact	Example	Elements
Force (Kinetic)	Move inanimate objects	Lift a box, pull a cart, wave a paint brush	Any one
Force (Potential)	Create or destroy inanimate objects	Construct a door, demolish a boulder	Any two
Light	Manipulate light waves to create illusions	Hide something in shadow, change someone's appearance	Intellect
Sound	Manipulate sound waves	Create silence, make a voice louder, create a loud bang	Spirit
Heat	Manipulate heat waves	Set a fire, cool something down	Empathy
Electrical	Manipulate electrical charges	Power a lightbulb, create lightning, charge a battery	Empathy & Spirit
Magnetic	Using and creating magnetised charges	Magnetise metal, pull objects together, force objects apart	Empathy & Intellect
Chemical	Changes at an atomic level	Create edible items, create chemical compounds	Intellect & Spirit
Time	Changes to the momentum of time	Slow things down, speed things up	All

Cost

Ardency is limited by the energy of the spellcaster

Magic from the Ardency is limited by the energy of the person. For a spellcaster, using the Ardency is physically, emotionally and psychologically draining, depending on the amount of energy used and the depth of their Ardency in the first place.

For example, a person tapping into their Ardency for the first time may begin to feel hungry, dizzy and or nauseous after casting a fairly basic spell, such as closing a door. However, someone who has trained and built up their Ardency's stamina may be able to send bolts of lightning through the sky for over an hour before they begin to tire.

Ardency cannot create or destroy life

For example, if someone feels deflated or in low spirits, their magic is less predictable. Or, if someone is tired and is less capable of connecting to their intellect, their magic is less complicated. Or if someone is feeling hurt and disconnected, their magic is low energy.

It is for this reason that it cannot be used to destroy or create life without also destroying the person trying to do such a thing, and even then it would take an extremely powerful spellcaster to succeed.
As the Ardency draws from a person's spirit, intellect and empathy, any change in these three things may impact a person's ability to use their magic.

Restrictions

While it is said that everything is made of energy, there are types of energy which don't mix or are far too complex to be able to manipulate. The most obvious example of this is with the Ardency itself.

Ardency cannot change another's Ardency

One person's Ardency cannot impact another's Ardency, nor can it change the elements which make up the whole of it.

For example, magic from one person's Ardency cannot affect the way someone is feeling (their spirit), what they know or understand (their intellect) or their relationships with others (their empathy).

Ardency cannot affect the spellcaster's energy

For example, a spellcaster cannot physically change their own appearance, make themselves faster or improve their own intelligence. However, they might change the light waves around them to create an optical illusion or slow down the world around them so it looks like they're faster.

While many have tried, it is not possible to use Ardency on one's own energy. The experience is something like trying to use dial-up internet while also calling someone on the landline; it makes all the noises as if something will happen and then disconnects.

Ardency cannot affect the mind or life of another

It is not possible to access the mind of a living creature or impact a life force. The few times this has been attempted this has caused the death of the spellcaster.

Spellcasters

While everyone has the potential to tap into their Ardency, not everyone puts the time and energy into doing it. Indeed, in a technologically advanced universe, the effort it takes for most to master Ardency is considered a waste of time.
There are a few for whom the elements of the Ardency align naturally, and the magic comes to them with greater ease than for most. However, even then some training and self-discipline are required to master it.
Anyone who attempts to tap into their Ardency can call themselves a spellcaster, but it is only those who are able to master all three elements of it at once who may call themselves an Adept.

Type

Magic System

Source

Ardency

Elements

Empathy
Intellect
Spirit

Empathy

Pro: Powerful
Con: Uncontrollable

Intellect

Pro: Complex
Con: Weak

Spirit

Pro: Controllable
Con: Simplistic

Cost

Energy

Users

High: Adept
Low: Spellcaster