Character Creation Edit
Tentatively, start with a DF delver template and add about 50 points in Power-Ups/Racial abilties/Lenses and another 50 points in Status, relevant non-DF skills (Administration, History, Intelligence Analysis), and the like.
- Stupid Wizards
To discourage spell-casters from taking IQ 16+ and then being strategic geniuses and expert diplomats, create a "Cunning" attribute that is the average of IQ and 10. All spells are now based off Arcana plus appropriate talent (Clerical/Druidic Investment, Magery). When using DF delver templtes, magic types have the option of buying down IQ to 12 and purchasing additional levels of talent.
Most "Wizards" are Ritual Casters using the "no core skill" option from Thau 73 and Thaumotology as their core skill. They cannot use Powerstones or Power Objects, have Variable Energy Access (Thau 79) with a Threshold of 20 and a Recover Rating of 5.
Wizards are born with magical ability. Some of them need to learn spells through careful study, while others know them naturally. The effects of the spells are similar, but the methods of acquisition are different and studiers can't learn from natural learners or vice versa. The colleges of the studiers are the standard GURPS spells, while natural learners use Ogham Tree Magic (or whatever whackiness other people suggest). This sometimes leads to weird effects: A studious master of Earth and Fire can cast advanced spells that a natural master of Alder can't, and vice versa.
Some wizards also study as priests. They are not Saints. They are just priests with Magery.
Most "Saints" are Ritual Casters using Ritual Magic (Theology) as their core skill, a TBD spell list, and a single Divine College* containing the entirety of their spell list. They cannot use Buffer (powerstones or power items) objects, have a threshold of 40 and a RR of 8, and are subject to Other Uses of Energy, Trading Fatigue for Power, and Some Fatigue Cost from Thau 80.
That's one Divine College for all "good" and all "evil" saints in the world. I'm using the CS Lewis "Narnia" model: if you pray to do good things, you're praying to a good deity, and if you pray to do evil things, you're praying to an evil deity. Your fate after you die depends on your actions in life, and there's no reliable way to determine your fate in life. Detect Good doesn't exist, and the high priestess of the goddess of Love and Kindness can cast "Summon Really Evil Demon" if she wants without the goddess being able to take power away from her. So there aren't any Pact Limitations, either.
The Saint spell list is approximately the Good Cleric, Evil Cleric, and Druid List from DF1 and DF3.
As a corollary, Sanctity doesn't depend on proximity to one's patron god's temple, but to the affinity of the local god to the spell being cast. Again, a priest of the goddess of healing and light is effectively praying to Kali when she casts a Murder spell, so it doesn't work so well in the Healing Temple but it works quite well in the Thugee murder pit.
Saints get their power from a will to believe, not the deity they are praying to.
Most Saints are priests, and identify themselves as servants of a particular deity. Not all are, but it's helpful to get instructions in magic from somewhere.
High level calamities just blow up the caster and destroy the things he cares for in a way that doesn't affect his enemies. It isn't possible to Samson one's enemies by deliberately casting a really difficult spell and hoping for a critical failure. Go earn your heroic victories!
Saints or Wizards will likely have the options of choosing Path magic. The exact details need to be worked out. Dwarven Runepriests are definitely going to use Path Magic.
Battlefield Magic Edit
Battlefield magic is as per the standard MC rules: a Mage Element is TS 5 with Artillery, C3I, Fire, & Recon class specials and an appropriate Move type and cost; it may have other specials as appropriate, and it can have whatever quality is appropriate.
In human armies, a Mage element represents 2-3 minor saints or full wizards, 2-3 focused wizards (who only know 1 College) or gadgeteers with magic items, and a small bodyguard of 4 soldiers. The bodyguard might be Sea Elf archers, human knights, dwarf heavy infantry, or Bone golems, depending on the element's movement type and idiom.