If magic existed in the real world, the source of its energy would depend on the specific fictional world or mythos in which it is grounded. In different mythologies and fantasy settings, magic is often associated with different sources of power. Here are a few examples:
Mana or Life Force: Many fantasy settings attribute magic to a form of energy called "mana" or "life force." Mana can be drawn from living beings, nature, or the elements. It might be replenished through meditation, rituals, or by harnessing natural energies like moonlight or ley lines.
Elemental Forces: Magic could be connected to the elemental forces of fire, water, air, earth, and other natural elements. Practitioners might tap into these elemental energies to manipulate the world around them. For example, fire mages would draw upon the energy of flames, while water mages would harness the power of water.
Cosmic or Astral Energies: Magic might be fueled by celestial energies from the stars, planets, or other astral bodies. Mages would tap into these cosmic forces to cast spells and manipulate reality. The alignment of celestial bodies or specific constellations could enhance magical abilities.
Spiritual or Divine Sources: In some settings, magic is derived from spiritual or divine sources. Practitioners might channel the power of gods, spirits, or other supernatural entities. The magic could be granted as a gift, acquired through pacts or rituals, or inherited through bloodlines.
Personal Energy or Willpower: Magic could be connected to the individual's own energy or willpower. Practitioners would tap into their inner reserves to perform spells and shape reality. Training and discipline might be required to enhance one's magical abilities.
These are just a few examples, and the source of magic energy can vary widely depending on the world-building and mythology of a particular story or setting. It's up to the imagination of the author or creator to define the source and mechanics of magic within their fictional universe.