The base stuff of magic, the raw energy that powers all magic everywhere, is called mana.  Mana is one of the basic building blocks of the universe, and the source of all life and energy.  The Gods themselves are beings of pure mana; the power they gain from the faith of their worshippers and feed upon is a form of mana.  When the Gods created the world, they formed it out of mana, and when a God causes a miracle to occur, he does so by ordering mana to his whims.  Mana is what makes existence itself possible.

The ultimate source of all mana is the Gods themselves.  Bluntly put, mana is a waste product created whenever the Gods manipulate reality.  Thus, mana is generated by certain special phenomena caused directly or indirectly by one of the Gods.  Lightning strikes, thunderstorms, hurricanes, tornadoes, forest fires, the full moon, a night of no moon, sex, birth, and death (especially ceremonial death) all create mana.  And when a spellcaster creates a magical effect, he is unknowingly imitating the gods by forcing manna to do his bidding.

Of course, very few mortal beings are even aware of the existence of mana.  To a mortal spell-caster, the methods used to create a magic effect are much more important than the magic itself.  For priests, magical effects happen through the power, symbols, and rituals of their faith.  Wizards use arcane and mysterious rituals and formulae to create magic.  Sorcerers create magic through sheer force of will and innate talent.

The sad truth is this: mana has been used at a much faster rate than it has been created.  Times long ago were much more magical than the age of the Young Kingdoms.  Legends of the long-lost elves speak of mighty sorcerers able to move mountains and shift the course of rivers at a whim.  Such tales also speak of a time when dragons ruled the world in horrifying numbers.  And there are stories of mortal-crafted objects of magical power that could challenge the very Gods themselves.

In modern Taranche, no wizard has the power to alter the world in such a way.  The elves are but a memory, dragons are few and far between, and while most spell-casters know how to cook up a potion or inscribe a spell onto a scroll, crafting truly awesome objects of power has become something of a lost art.

This is not to say that the power of the spell-casters is diminished.  There is enough mana left in the world to power all the spells a wizard could ever want to cast.  A wizard is still a powerful and fearful thing.  Rather, it is the scope of the magic that had been reduced.  The time of legendary magic has passed; with it went the time that dragons filled the sky, that elves created towers of ivory and glass, and wizards shook the very foundations of reality.