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. Most of the magic used by warlocks is used to manipulate their surroundings, rather than using pure magic as brute force. 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.
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.
- Sebastian Morgenstern — has shown ability to conjure illusions
- Ty Blackthorn — partially succeeded in utilizing a spell from the Black Volume of the Dead in an attempt to resurrect Livvy
- Tatiana Blackthorn — spent years studying dark magic in hopes of raising her son, Jesse
- James Herondale — has the power to enter demonic realms and turn into a shadow, being the grandson of Belial
- Lucie Herondale — has the power to command the dead, being the granddaughter of Belial
- Grace Blackthorn — has the ability to entrance men, due to the machinations of Tatiana Blackthorn and Belial
- Kit Herondale — ability borne from his fey lineage
- Valentine Morgenstern — spent years studying magic
- Mundanes (Witches)
- Axel Mortmain — a mundane who used magic from the Book of the White to prolong his life force; created an automaton army by binding demons to human-like machines
- Wren — a Sighted mundane and self-taught witch who paid a warlock to teach her basic spells
- Unidentified group of men who summoned the demon Marax in the late 1800s; their lack of skill and knowledge in the field led to them not binding the demon, allowing it to kill them all.
- Madame Dorothea — a witch who lived as Clary and her mother's neighbour in Park Slope. Her adoptive mother was a warlock, and taught Dorothea some magic.
- 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; this also includes any form of teleportation that involves traveling between dimensions, such as the rings of Valentine and Sebastian Morgenstern;
- Geas — spells used to impose an obligation or prohibition magically on a person;
- 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;
- Objects — sometimes, inanimate objects can be enchanted to contain or be used for some magical purpose;
- Oneiromancy — the magic of dreams, manipulate them, only performed by very powerful magic-users;
- 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;
- Sacrificial magic — the use of energy from deaths to achieve an end. Typically the chosen victims will have to have something in common between them; ie. they are all virgins, have the sight, have the same blood type, etc. A sacrificial circle must be drawn in order to perform sacrificial magic;
- Summoning rituals — the summoning of either demonic or angelic entities;
- Sympathetic magic — used in objects or actions symbolically associated with an event or person;
- 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 possibly the rings of Axel Mortmain;
- 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;
- Wild magic — an ancient kind of magic performed by faeries, like the Wild Hunt or the Riders of Mannan.
- 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.