One of the first things you learn as a mage is that "magic" is just a blanket term for a dizzying variety of strange powers and abilities. The steps you take to summon a lightning bolt from the heavens are completely different from the steps you take to heal a wound.
Magic is broadly grouped into categories known as spheres. Spheres cover a particular way to work magic, involving similar occult symbols and rituals.
Spheres are treated like skills. Every rank you buy in a Sphere costs 1 experience point.
Every rank of a sphere you purchase allows you to add 1 spell of that sphere to your spellbook.
Spells are categorized, broadly, into spell levels that define a spell's relative power. Most mages can only access spells up to sixth level.
You unlock higher levels of spells at the following ranks in the sphere:
1st Level: 1 Rank
2nd Level: 4 Ranks
3rd Level: 7 Ranks
4th Level: 10 Ranks
5th Level: 13 Ranks
6th Level: 16 Ranks
If you are trying to affect a target with a spell, you make a Spell Check against the defence indicated by that spell. This check is equal to:
d20+your ranks in the Spell's sphere+the sphere's ability modifier+the spell's level
If someone is attempting to make a check against your spells, such as to dispel it, the DC is equal to:
10+your ranks in the Spell's sphere+the sphere's ability modifier+the spell's level
Casting a Rote Spell takes 1 Action, unless otherwise noted in the spell's description.
Casting a Rote Spell provokes Attacks of Opportunity from foes you are in Melee with unless you take 1 Action to Cast Defensively.
Casting a Ritual Spell takes the next time unit higher to cast.
A spell with a Rote time of 1 Reaction has a ritual time of 3 Actions
A spell with a Rote time of 1 Action has a Ritual time of 1 Minute
A spell with a Rote time of 1 Minute has a Ritual time of 1 Hour
A spell with a Rote time of 1 Hour has a Ritual time of 1 Day
Spells cost anima. You can either spend anima from your Anima Pool, or you can use Spellcraft to Channel Anima. A spell costs an amount of anima equal to 2 x the spell level. So a 1st Level spell costs 2 Anima, a 2nd Level Spell costs 4 Anima, and so on.
A spell with variable levels has different effects depending on the amount of anima you channel into the spell. It only counts as one spell known for the purposes of learning spells or your rote spells known.
When you learn a variable spell, you learn to cast it at all the spell levels you can cast for that sphere. Each time you unlock a new level of spells in that sphere, you unlock the ability to cast the variable level spell at that increased level.
The concentration required to cast a spell is sufficient to cause you to briefly lower your defenses. If a foe is in Melee with you, casting a spell proves an Attack of Opportunity unless the spell's description specifies otherwise.
Normally, you can concentrate even in a distracting situation, but if you’re casting a spell and you take damage from either a successful attack that targeted your AC or from an effect that you failed a saving throw against, the spell fails.
You can take 1 Action to Cast Defensively and deny enemies an Attack of Opportunity against you spellcasting actions until the start of your next round.
If you ever try to cast a spell in conditions where the characteristics of the spell can’t be made to conform, the spell fails. For example, if you try to cast a banishment spell on a human on the Mortal plane, the spell fails.
The Sphere of Air includes spells that involve the primordial element of air.