This text was taken from "Magic" page, written by DrDoodlittle.
What is Mana?Edit
Mana is a force and a source of magical energy as a whole. All spells require mana, so this means a mage will require a Mana source. The world leaks out mana like a sponge being slowly squeezed, so it should be easy to use, right? Wrong. Only 15% of the world's population can use magic, and it is a very complicated and precise practice. "Mages" in general are just people that can use the energy of the world-however, there is a limit on what a person could use.
Think, if you will, a sink. And that sink is connected by a long tunnel of pipes to a water source. The sink is the spell and the lake is the world's mana. The piping is the mage. For a mage to make a spell, he must use mana. For him to use mana, he must be tuned and crafted and trained so he can do it in JUST the right way. Then the mana flows through the person and is directed into a spell. Voila, magic.
Magic Abuse & Mana DependancyEdit
But if this was the case, then magic would be limitless and too destructive. So if a person uses mana too long, they get what is known as Mana Burn. Mana Burn is a sickness that only mages can contract from exhausting themselves by using magic. No mage can cast without a price, and sometimes the price is far too great. Therefore, even if you are in the 15% of mages in the world, you can only hope that your "Mana Pool" (how much magic you can use naturally) is large enough to hold the spell up.
Mana Burn is a warning. You can keep casting your spells, no problem. However, if you keep casting too long, you will inevitably die from Mana Exhaustion-The loss of all the mana in your body.
You see, mages always have mana in them, like a hose still holding water. Their body NEEDS mana, and to be without mana spells a mage's death. ALL MAGES MUST HAVE MANA TO LIVE! Their body depends on it, and because of the dependent attitudes, mana is tied with their life.