Defensive Magic

Defensive Magic is pretty much a basic cornerstone of combat magic, something that every person willing to dabble in the arcane arts must learn and sooner rather than later. Without it, even the most powerful magician would be vulnerable for getting killed by a single enemy archer. Which would have rendered entire magician trade a rather suicidal thing.
Pretty much every type of Modern Magic (and many types of Old Magic as well) include at least some defensive spells and hexes. There are all divided and put neatly into tables by the Imperial Magic Guild (as most magical things are).
On its most basic level, the Defensive Magic can be separated into three basic categories: Passive, Active and Evasion. In most cases - especially by magicians, but also competent sorcerers - they are used simultaneously. While costly and difficult, such system offers maximum possible protection.

---

Passive Defensive Magic

First type of Defensive Magic, that is also the most common... because it's easiest to learn and its most cost-effective. While it's further divided into two subcategories, their basic trait remains the same. Passive Defenses does not require caster's attention until they broke or are badly depleted. They work automatically once casted, stopping or weakening incoming attacks. They are divided into Bulwark and Armour spells and hexes.
The Bulwark Magic work by projecting a field of magic surrounding the caster that is used to stop incoming attacks. Basic example of it can be an Magic Shield, an Arcane Magic defensive spell that covers the caster in mostly transparent bubble of magic that works pretty much physical armour. More advanced and slightly different examples: Unlife Barrier and Bend Reality. The former is essentially a bubble of Death Magic, causing intense and painful debuffs and damages to organics trying to attack the caster at melee rangee and destabilizing spells, that can do little to material projectiles. The latter is a destabilized space surrounding the caster which reacts to incoming attacks by partially collapsing and negating them, originating in Doom Magic.
Armour Magic work by reinforcing the body of the caster, in a way similar to defensive Aura Manipulation. Unlike the Shield Spells they aren't expected to stop damage completely, they are a last line of defense supposed to weaken damage to survivable levels. They mostly work by caster's imbuing his skin with a lot of magic of certain type. Examples: Arcane Armour and Inhuman Resilience, common Armour Spells of Arcane Magic and Doom Magic respectively.

Active Defensive Magic

Second type of Defensive Magic, that works mostly as an addition to Passive Defenses. Unlike them, they typically are neither omni-directional nor automatic and require caster's attention. Rather than being 'bubbles' surrounding him, most of them are very short lived and are more of a short-range spells/hexes that just happen to be useful in defending yourself from enemy attention. They are internally divided into two subcategories: Shield and Control Magic.
Shield Magic can be more or less summarized to be a very localized version of Bulwark Spells anchored to ones hand/catalyst They aren't made to negate incoming damage completely, and are sort of a middle layer between Bulwark and Armour Spells - after an attack pierces through the Arcane Shield (for example), it is then intercepted by a Shield Spell (for example a Localized Distortion of Doom Magic) by caster purposefully hiding behing his staff. Only after this defense is broken as well, the attack can hit the last line of defense, for example an Arcane Armour cast on caster's body.
Control Magic are defensive spells that works on a different princinple than the rest. Rather than being cast on the caster to protect him, they are cast on the enemy that endanger caster's wellbeing (while not being an explicitly offensive magic). This subcategory includes spells that are supposed to force melee combatants back from the melee range, cause enough confusion for the caster to flee and so on.

Evasion Defensive Magic

Third and final variant of Defensive Magic. Rather than absorbing enemy attacks or making sure they can't stab you on close distance, the Evasion Magic works by helping you not be hit by an attack at all. In short - it allows you to detect and dodge incoming attacks. Hardest to use and, typically, rarest to encounter... while being very, very troublesome to deal with.
Movement Magic - In short - a magic that lets caster rapidly move from point A to point B. By either short-range teleportation or something similar. This allows to both avoid melee combat and an incoming attack that is deemed too powerful to defend against in normal way (or simply would deplete too much from the passive defenses magic. Used mostly by better sorcerers and magicians.
Detection Magic that is supposed to detect incoming attacks early (or even predict them, in case of some high leveled spells). It is mostly an addon to Movement Magic (allowing caster to dodge the incoming attack), or Shield Magic. Also helps in avoiding instakills, though it's always possible to slip one or two (no unkillable people there).