During the God Design phase you can, and must, set magic skills for your Pretender God. Picking new paths and putting more points into current ones costs Design points, and the cost to pick new paths is announced when you select a physical form for your pretender. When adding level in a path, each additional skill level costs 8 design points *more* than the preceding, so it is very expensive to reach the 9 levels necessary for the special "bless effects". Generally you have to select a pretender with a starting level of 3 in the chosen path.
The amount, type and strength of magic you pick for your pretender also affects your Divine Titles and more importantly your bless effects.
There are eight Paths of Magic you can choose from, and you can place at max ten points of each skill at start for your Pretender. Levels of these paths also appear on the numerous mages of the world, but there are practically no mages who go over 5 picks in some magic skill without empowering or items. Pretender Gods can, and if the player wants to use a bless strategy will go beyond five picks. On the other side some players like to use low-magic gods.
All magic paths give you +5 to Magic Leadership per pick. Note that high levels (5+ in each) combinations of Air/Earth or Fire/Water magic allow the forging of the path-boosting Staff of Elemental Mastery.
Air
The Path of Air deals with controlling the different manifestations of air such as lightning, wind or illusion. Air nations possess the means of magical flight and can conjure up large armies of phantasms on the battlefield supported by massive lightning storms. Air mages gain +1 Precision per level of Air magic.
Air magic offers powerful and accurate electrical attacks and immunities, useful protective wards and glamours, flying and good summons. When combined with Death or Earth it allows the creation of Corpse Constructs (shock- and cold-immune undead) or Watchers (lightning-throwing statue guardians). Magical items include Robes of Missile Protection, Chainmail of Displacement, Winged Shoes,Spirit Helmet and Staff of Storms. When combined with Blood or Earth, it allows forging Robes of the Magi. Gems collected from Air Magic are called Air Gems.
Astral
Astral is the first source of magic and draws its power from the celestial spheres. It is very versatile, offering some of the most powerful late-game spells and rituals. It can be used to alter the fate of the battle or used to empower or dispel other spells. Astral Mages gain +10 magic leadership per level.
Astral magic allows the boosting all other paths of magic through spells (Power of the Spheres) and forged items (Ring of Sorcery, Ring of Wizardry, Crystal Shield) and thus combines very well with every other path. It allows forging of the devastating Ethereal Crossbow or turns your mundane commanders into sacreds with a Shroud of the Battle Saint. Astral enables a wide variety of unique and useful powers: Teleportion and Dispeling magics, protection buffs such as Body Ethereal, Resist Magic, Twist Fate or Astral Shield and mind-altering combat spells such as Enslave Mind, Mind Burn, Astral Tempest, Magic Duel, Paralyze, Horror Mark and Soul Slay. Astral mages can form Communions so as to empower each other in battle and share fatigue. The most powerful astral mages can Wish for just about anything.
Astral magic gems are called Astral Pearls. All other magic gems must be first alchemized into Astral Pearls if one wants to alchemize gems from one type to other.
Blood
Human Blood is the second source of magic and it is banned by most rulers. The majority of Blood spells require a second magic path to cast, and thus this magic school can be seen as complimentary to (or a corruption of) other magic. As such, only Rainbow mages will gain access to the full compliment of spells and rituals. Blood spells often call forth powerful demons, fallen angels, crossbred abominations or Horrors, both in the form of summons and globals. Battle magic also manifests as fatiguing combat spells that deal with burning, boiling, bleeding or draining blood from your enemies or conversely the healing or recuperation of friends. Arcane forging offers a diverse assortment of diabolical weapons and contracts as well as useful items which control fatigue, aging and death itself. Mages of the Blood Path can command five undead units per level in Blood magic as well as form Sabbaths (Communions) similar to those of Astral mages.
The lore of the individual nations notwithstanding, in fact any pretender can take blood magic and commanders can bootstrap into blood during the course of the game, even if their nation doesn't normally have blood mages available at start. It's sacrificial rites and techniques are unlike any other magic Path, as you MUST expend Blood Slaves to cast any spell. The Blood Hunt command is used with your commanders to gain Blood Slaves - sacrificial virgins used to fuel the Blood spells. These are the "gems" for Blood magic, but in battle Blood Slaves appear as units and can be killed. On the strategic map they go into the commander's gem box like other gems.
Note that you can not alchemize Blood Slaves into or from other magic gems.
Death
The dark path of Death deals with necromancy, reanimation rituals and destruction of life. Among Death's hallmark strategies are huge undead armies led by powerful SC generals lording over provinces devoid of any living being. A strong knowledge in Path of Death is required to command great hordes of undead. A mage can lead 20 undead units per one level of Death magic. Each 5 levels of Death magic bestows a Fear Aura of +1 (ie. at Death 5 a commander gains a Fear (0) aura), whereas each individual level of Death increases the area effected by a Fear Aura by 1.
Death magic offers numerous summoning spells, both in the laboratory and on the battlefield, that call forth undead creatures ranging from hordes of lowly Soulless to terrifying Tartarian Titans and immortal Liches. Death magic allows mages to cheat death itself and come back from the grave. Death has some of the most widely destructive and population-killing late-game Globals as well as powerful combat spells such as Disintegrate and Soul Vortex. Forged items include weapons that can cause leprosy or aging as well as items that magically increase research and experience. Death magic gems are called Death Gems.
Earth
The Path of Earth deals with the control and enchantment of the different manifestations of earth such as metal, stone and the very ground. It is the magic of protective armor and re-invigoration. Earth magic is essential to create magical items inexpensively through forge bonuses. Earth mages receive one point of Protection for each level of skill in Earth magic.
Earth magic offers many potent battle spells and protection buffs such as Petrify, Earthquake, Rain of Stones, Invulnerability, Legions of Steel, Weapons of Sharpness, Blade Wind, Destruction, Summon Earth power, Marble Warriors, Army of Gold and Army of Lead. It combos well with Astral or Fire magic, both on and off the battlefield. Earthen magic items include the prized Dwarven Hammer along with simple armors and weapons, but adding Astral or Fire magic to the mix makes available such powerful items as the Crystal Shield, Crystal Heart, Crystal Matrices and Fire Brands. Summons include regenerating Trolls, ethereal Fall Bears and many magically animated constructs.
Earth magic gems can be alchemized into 10 gold each.
Fire
Fire is the most violent and destructive of all Paths of Magic. Fire mages carry an aura of righteous authority that helps them lead great number of troops, and the mages tend to be violent and aggressive. They receive a bonus to Attack skill for every level in Fire magic.
Fire magic spells mostly deal with shooting fire at enemies, setting them on fire, blinding or restraining foes, or evoking wreathes of protective flames. It has a great number of different spells in Evocation school. Summons include fire-spitting drakes, fiery lions and serpents, ancient magi forgotten in tombs under sun-scorched sands, and Elemental Kings of living fire. Fire can remotely rain destruction on enemy armies, and burn the world into a sun-scorched dessert. When combined with Astral it can sear hordes of undead and demons in holy light. Combined with Earth it offers magma spells and enables the forging of many useful items. Whereas combined with Water it allows the use of acid magic in battle.
Fire magic gems are called Fire Gems and they can be alchemized for 15 gold each.
Nature
The Path of Nature deals over the control of different manifestations of nature. It includes control over plants and animals as well as manipulating states of mind and body such as healing wounds, poison, causing fatigue and shape-shifting. A mage of this path can feed 10 troops per skill in Nature and any regenerative powers of the mage are boosted (~5% of max hp per nature level). Also, each extra level in the path of nature adds some years to the commanders maximum age, taking away any old age status if it surpasses current age. The amount of years added depends on the base max age the unit has (~+50% base max age per nature level).
Nature magic has spells that drive people to sleep or berserk fury or give them regenerative powers and spells that tangle people inside masses of vines, conjure forth clouds of poison, turn enemies into swine, transform the caster into a beast, or evoke overpowering streams of life energy. Nature magic also has many useful magic items that offer recuperation from fatigue, poison damage, berserking or feeding troops, regeneration, lycanthropy, blinding or entangling enemies. Summons include various creatures of Nature from Wolves and Vinemen to Bog Beasts and mighty Tarrasques (poison spitting Dragons). Combining with Death allows summoning armies of Manikin warriors (undead that attack using sleep and entanglement). Nature magic gems are called Nature Gems.
Water
The Path of Water deals with the control of different manifestations of water and ice such as rain, seas, snow and frost. It is the magic of winter, the sea, speed and defense. Water mages gain increased Defense skill for each level.
Water magic has a number of useful combat spells such as Breath of Winter, Winter Ward, Cold Bolt, Sailor's Death and Niefel Flames, as well as spells that specifically give boosts when fighting underwater. Pure Water has a variety of summoning spells such as Call Kraken, cold-aura Winter Wolves, Sea King's Court (a Sea Troll mage and his entourage) and Queen of Elemental Water (an elemental royalty SC that regenerates 100% hp each round) while combined with Nature or Earth offers Naiad Warriors (elite awe troops), Dryads (powerful casters), Manifest Vitriol (poisonous Lions) or Claymen (regenerating magical constructs). There are many acid-based combat spells available when combined with Fire. Water & Death go hand-in-hand, as the dead are not affected by winter's icy touch while Kokythiads (amphibious magi) bring their magics to bear. Water globals generally only affect sea or coastal provinces and can block access to the sea. Water magic has some strong magic items such as Frostbrand, Boots of Quickness, Demon Bane and Sword of Swiftness and items that allow commanders to go under seas with their troops. When combined with Nature or Air it offers the useful items Clam of Pearls and Amulet of the Fish (aquatic units can leave the sea). Water magic gems are called Water Gems.