Warning: the following contains SPOILERS for The Witcher.
Magic functions differently in Conjunction of the Spheres, which happened around 1,500 years before the events in the novels. This cataclysmic event caused Chaos from different planes to merge with the magical energies in the Continent, forever altering the nature and future of our reality.
Chaos, also known as Force or Power, is drawn from the primary elements – air, earth, fire, and water – from which four of the branches of magic are based, which additionally includes the branches of mind and divination magic. A more powerful fifth element called Ether refers to Chaos drawn directly from the Astral Plane, although Ether can also be harnessed by combining the primary elements. This is the system used by all sorcerers, mages, and other magic-s across the multiverse. Although innate Chaos wielders known as Sources are the only ones who can truly realize the incredible potential that magic holds, simple spells like the signs used by Geralt of Rivia (Henry Cavill) and other witchers can be learned by almost anyone at little cost. Moreover, for reasons yet-unknown to those who study magic, women have a more natural predilection for controlling Chaos than men, for whom the cost of magic is usually greater.
The Witcher focuses greatly on the cost of harnessing Chaos in order to use magic. Wielding Chaos and magic entails sacrifices to achieve the desired effect and its magnitude. This can be observed in Tissaia’s (MyAnna Buring) lessons at Aretuza, during which mages-in-training sacrifice small living things or parts of themselves to perform basic spells. In general, the greater the spell, the greater the sacrifice needed – as seen in how Yennefer (Anya Chalotra) nearly kills herself and temporarily loses her innate Chaos when she uses fire magic to turn the tide at the Battle of Sodden Hill. This is why Sources, those with Elder blood like Ciri (Freya Allan), and other natural magic s face constant danger despite their ability to easily unleash incredible power. Indeed, the physical injuries caused by mismanaged Chaos pale in comparison to the mental and spiritual anguish experienced by Sources who’ve gone mad with the knowledge of the multiverse. Unlike the use of mana as a source of magic in other more traditional fantasy settings, magic in The Witcher comes at the cost of life itself – a reflection of the recurring theme of sacrifice throughout the series.
This is why some organizations, such as the Brotherhood of Sorcerers, either limit or completely forbid certain types of spells and practices, both for practical and ethical purposes. For instance, the Brotherhood forbids fire magic except in the direst of circumstances, as its cost is deemed too great for everyday use. The same can be said of necromancy or death magic. Disturbingly, as the kingdom of Nilfgaard’s mages reveal, some magic s actually sacrifice human lives for powering spells, a practice that’s even more frowned upon than fire-based and necromantic magic. While most mages in the Continent adhere to these rules, there are some who completely ignore them, risking their limbs, organs, and minds in the pursuit of absolute power.
The Witcher’s rules for wielding Chaos and magic are an examination of the heavy costs of attaining and maintaining power in the world. While the effects of Chaos and magic only exist in fantasy, these concepts are also analogous to the driving forces of modern capitalism, geopolitics, and everyday social interactions. The evolution of Chaos-born magic – both as a tool in the multiverse and as a form of social commentary – will continue in The Witcher season 3.