Magic in Orre
What is magic?
In Orre, it's fairly uncommon to find someone without at least a little magical capability. Though this ability is extremely raw and unpredictable when untrained, a mage who undergoes training and attempts to wrangle the power inside will be quickly rewarded. However, the power of your average mage is somewhat limited. Every being in Orre is considered a vessel for things of unlimited power known as a Soul. When a Soul is ripped from the spirit plane the trauma causes it to align with one of the six elements:
Air: Not just making tornadoes, the ability to control air also includes the ability to move particles, create sound, and create lightning. Fire: Along with providing a dazzling light show, one who controls fire also controls space and emotion. Rock: Rock applies to the control of solids. It's also believed to be responsible for the creation of living vessels. Water: Some can control water in all of its forms. Water is also attributed to time and intelligence Light: Along with making sure you can see, light can be used to gain knowledge and help tether a Soul to a weakened body. Dark: Along with making sure you can't see, dark controls death and the purest essence of magic. It's often the source of most necromancy.
With a little training, a mage can learn to control and use their own element. With substantially more training, a mage can learn to control a secondarily innate element, and combinations of certain elements will allow access to a third group of spells. A well trained mage can be a real force. Though a mage can never truly master other elements, with enough study they can gain some ability with other magic.
How magic will work in this campaign
I will be using the Ritual Magic Rules as described in Thaumatology and Magic. There are a couple limitations, however. A typical mage may specialize in, at most, two basic colleges of magic. A mage with more experience will be able to take a third college based on the combination of basic colleges they possess, as described below. They can still cast other spells at a default as Ritual Magic allows, however they cannot improve that ability without consequences.
Schools of magic
Air: Air magic corresponds to its like named college. Simple!
Fire: Fire also corresponds to its like named college.
Rock: Corresponds to earth.
Water: Corresponds to water.
Light: Corresponds to healing spells (not Light&Dark)
Dark: Corresponds to light and dark spells.
Combinations
Rock/Light: Animal Spells
Rock/Air: Body Control Spells
Light/Air: Communication and Empathy spells
Fire/Rock: Food Spells
Fire/Water: Gate spells
Light/Dark: Necromantic spells
Rock/Dark: Making and Breaking Spells
Water/Dark: Mind Control Spells
Rock/Water: Plant Spells
Air/Fire: Protection and Warning Spells
Air/Dark: Sound spells
Air/Water: Weather spells
Light/Water: Illusion and Creation Spells
Fire/Light: Knowledge Spells
Wild Magic
A mage who wishes to master more than three colleges starts approaching realms of magic that are unpredictable and unstable. In order to take four or more colleges, a beginning mage must take the -50% "Radically Unstable Magery" limitation (Thaumatology P. 26). Over time this can be bought off up to the -10% version. Critical failures for this version of magery won't roll off the typical table, instead I'll be using a Wild Surge table I have from a computer game I used to play (probably modifying it on a case by case basis to make it work better for GURPS). Results range from harmless things such as a rain of frogs or a mist of bubbles, to harmful things such as summoning demons and being launched into the air. It also includes the incredibly bizarre, such as making everybody within ten yards to fall in love with you, and the beneficial, such as permanently enchanting something with the spell you wanted to cast at no cost.
Setting wise, it's possible for a mage to study wild magery rather than typical magery that advances into wild territory, meaning A mage who wants to use Wild Magic may take it from the beginning.
Divination, Metamagic, and Enchantment
As these don't feel necessarily like they should be limited by elements, these types of spells will not count as "colleges" where limitations are concerned. Enchantment is still up in the air, at the moment. Meta-Magic is available to anyone.
Each basic path will have one or more divination abilities associated with it. Treat divination as if it were a spell in your chosen college(s) if you the have the appropriate element, otherwise treat it as a default. Remember that you only need one of the listed elements to use that method of divination.
Astrology: Dark, wind, Fire
Augury: Dark
Cartomancy: Light
Crystal Gazing: Rock to scry crystal, Water to scry water (at no penalty)
Dactylomancy: Fire, Wind
Extispicy: Light, Rock
Gastromancy: Wind
Geomancy: Rock
Lecanomancy: Water
Numerology: Water, Fire
Oneiromancy: Dark, water, wind
Physiognomy: Light, Fire
Pyromancy: Fire
Sortilege: Rock, Wind
Symbol Casting: Light, Dark
Legality of Necromancy
In many fantasy settings Necromancy is usually looked down upon if not outright banned by society. In Orre, it is believed that when you die your soul returns to the spiritual plane and your body remains as an empty vessel. Because of this view, necromancy is merely seen as enchanting a corpse, much as one might enchant a chair or a staff. Though most necromantic spells can be aggressive in nature and most would prefer you don't practice it in the streets, there is no repercussion to telling someone you reanimated their dear aunt Sally the other day. They may even invite you in for tea.
However, due to this view, forcing a soul to remain on this plane is seen as the most abominable and evil act one could commit. Resurrection spells are frowned upon, and summoning spirits is a good way to get an angry mob on your tower door step. Becoming a Lich won't win you any friends either (well, not any living ones). Knowledge of these kinds of spells is highly illegal, and casting them can lead to legal and social consequences.