Magic is the supernatural element that influences certain aspects of the lives of the Shadow World's inhabitants. Magic can be manifested as either seraphic or demonic.
Demonic magic is possessed by demons and Downworlders, and other beings affiliated directly with them and the Void, that grant them their inhuman abilities and powers. Demonic magic is considered dark or black magic only when used for harmful and malicious purposes and/or demons.
The magic of the fey and the warlocks are mutually exclusive and both individually powerful, though not much else is known about faerie magic. While these two groups actually use their magic, for the remaining group of Downworlders—vampires and werewolves—the demonic magic is merely "installed" in their souls.
Magic enables warlocks to cast spells and practice their organized and researched magic. The power of a warlock's magic apparently depends on their demon parent; Greater Demons often give birth to more powerful warlocks than the rest. The magical secrets and records of the warlocks are kept in their secretive Spiral Labyrinth.
However, there are warlocks who are somewhat incapable of using magic, known as ifrits.
Shadowhunters are incapable of, and forbidden from performing magic. However, they actually use magic almost regularly. Glamour, the simplest among all magic, is most frequently used by Shadowhunters as well as the other Shadow World denizens, their wards, and most of the tools given to them by the Angel Raziel, such as the Mortal Instruments and their runes, are actually magical.
Their Portal, created with the help of warlock Magnus Bane, also uses a form of magic not accessible to the Nephilim. Some of their weapons also use materials with magical properties; adamas, gold, iron, silver, and electrum are said to be good conductors of magical energies, and rowan from the European tree has magically protective properties.
Mundanes are typically incapable of using magic. However, with practice and usually blessing from demons or training from warlocks, some people who fancy themselves magicians or witches dabble in magical arts and find themselves able to successfully perform some spells or summon demons in the same way warlocks do. One such known case was in Charlotte Fairchild's youth, when a group of men summoned the Greater Demon Marax; their lack of skill and knowledge in the field led to them not binding the demon, allowing it to kill them all. Other examples include Axel Mortmain, the adopted son of a pair of warlocks, Valentine Morgenstern, and the young witch Wren, who were known to have studied and used some form of magic successfully. Mortmain was able to use magic for an assortment of tasks, not the least of which was slowing his aging.
Much of the magic available to Nephilim were gifts from angels. Angels also have powers possibly going far beyond conventional magic.
Demons, like warlocks, utilize what is termed as "demonic magic", though their use of this is mostly darker than that of most Downworlders.
- Magnus Bane — the High Warlock of Brooklyn; an old and powerful warlock capable of a variety of spells
- Ragnor Fell — the High Warlock of London; one of the few warlocks capable of dimensional magic
- Malcolm Fade — the High Warlock of Los Angeles
- Catarina Loss — uses her magic ability for healing
- Tessa Gray
- Valentine Morgenstern — spent years studying magic
- Mundanes (Witches)
- Demons — known to utilize "dark" demonic magic
- Battle spells — spells used in battle which include attacking with fire, acid, lightning, venom, poison, among others;
- Binding (and unbinding) spells — infuse demonic energy into inanimate objects, giving it life; used on vampire motorcycles and automatons;
- Demon possession — the possession of a mundane human's body by a demon;
- Dimensional magic — used to move from one dimension to another, as used for Valentine's obsolete apartment;
- Healing spells — spells used to heal wounds, injuries and poisoning;
- Hellmist/hellsmoke — a rare but powerful magic used as a weapon; a kind of conjured demonic fog that mutes the effects of other magic;
- Mind control — the domination of a weak mind against its will;
- Necromancy — the use of death energy to bring back the dead;
- Projection — the projection of a being's image without being physically present;
- Protection spells — also know as glamours; spells used to shield a person or place, often to fool mundanes into believing that what they see is something different from what is truly there;
- Summoning rituals — the summoning of either demonic or angelic entities;
- Tracking spells — spells used to find the location of an individual; requires any personal belonging of the individual;
- Transportation spells — spells that magically teleport people or things from one place to another; includes the Portal and the rings of Axel Mortmain, Valentine and Sebastian Morgenstern;
- Twinning rituals — a dark ritual that inextricably binds two individuals together, comparable to the parabatai ceremony but more powerful and dangerous, also making one of the pair superior over the other, the connection making the submissive one forget or look over facts he would typically care about; a variant of blood magic
- When performed correctly, a powerful ceremonial marriage can give a person the ability to access their spouse's magic or abilities or even grant the power to control the spouse.