Magic in the Known Lands is different than your standard Vancian or 4e power system. While the Vancian system is dated, and the 4e Magic Power system is what is hot these days, Wizards in the Known Lands use the Dynamic Spellcasting System presented in both Sovereign Stone d20 and Advanced d20 Magic published by Guardians of Order (defunct).
The system works like this:
Casting any spell is a standard action that requires no special words or gestures and no other ingredients. A character that knows a spell may cast it as often as he or she desires, with no preparation time or additional study required. Spellcasting is draining, however, and most people will get worn out after a prolonged session of working magic.
In game terms, casting a spell requires a Fortitude Save against the spell’s Drain. The result of the Save determines the amount of Drain suffered by the caster. If the Fortitude Save is failed by 10 or more, a Control check will also be required to determine if the spellcaster can maintain control over the flow of energy coursing through him or her.
The casting DC of a spell is given in the spell description. This is the DC for the Fortitude Save to resist Drain. If the spellcaster is using the Metamagic Feats, the modifier for the Metamagic effect adjusts this DC. When determining the Drain, use the spell’s total DC, including any modifiers for Metamagic. The character makes their Fortitude Save and consults the Spellcasting Fortitude Saves and Spell Drain tables to determine the actual Drain suffered. This Drain is
normally deducted from the character’s Energy Point total, or in the case of the system we are using, it inflicts non-lethal damage.
This allows wizards to bust some heads with the fighters, but provides its own terrible balancing cost. Too much drain (non-lethal damage) can cause fatigue, exhaustion, or outright unconsciousness.
Drawbacks: record keeping and mathematics, but that is about it. A calculator maybe required to quickly add and subtract any modifiers to a spell's DC.
What's wrong with 4E's Powers?
Uhm, you can only do some powers once a day. The Dynamic Spellcasting system lets you cast any particular power or ritual as many times as you want as long as your character has the stomach for it. This includes the Wish spell (which has a DC of 101, good luck casting that ten times a day and not having your wizard go unconscious).
I hate math, I want to use another system!
Okay. Go ahead, I'm not making you. But the Dynamic Spellcasting system is the official system. Any one spellcasting NPC will have Dynamic Spellcasting statistics.
Okay, Why the Dynamic Spellcasting System?
I like the system. And I'm the one writing the game, so I'm using what I like. You can use any system you desire that is easier for you, but like I said, the Dynamic Spellcasting system is the official magic system of the campaign.