One Power

In Robert Jordan's Wheel of Time books, the One Power is the energy that flows through everything. It is separated into two halves: Saidin - the male half; and Saidar - the female half.

Each half of the One Power can be used only by people of the appropriate sex. Furthermore, not everyone has the ability to "channel" the One Power. Some people are born with the ability in them, and many more are born with the ability to be trained in it.

The Aes Sedai are the largest collection of women who officially use the One Power. They refer to all women who learn to channel on their own as "wilders".

Men who can channel almost inevitably go mad, due to the Dark One's taint on Saidin.

Furthermore, all men and women who learn to channel on their own come to a point of crisis, in which they are in severe danger of dying without training. Many women who die of mysterious circumstances in their late teens are actually wilders who have failed to cope with their abilities.