Compulsion is the name for the art of subjugating another person's will through the use of the One Power.
The lesser form of Compulsion is described like a whip, and makes the subject nervous and giddy, but the more advanced Compulsion compels the subject to worship the user. Both forms require using the Power to stimulate and control nerves in the brain, and forcing too hard can damage a person's mind permanently once they are released. Additionally, the greater the user's knowledge of the functions and anatomy of the human brain, the more effective their Compulsion becomes; this in part explains Graendal's unmatched mastery of it.
Normal use of Compulsion is to channel the Compulsion weave, often described as whip-like and making use of mostly Spirit, and then to issue a command. The victim will then carry out the command of the channeler. Through normal use, Compulsion is not thought to have any lasting effects. Repeated use on the same subject, however, can lead to the subject being more likely to be obedient, even if not under active Compulsion.
Some people have the strength of mind to try and resist Compulsion subconsciously. If they are able to resist, they are then able to free themselves of the implanted command. This does not, however, protect the victim from a subsequent or more powerful use of Compulsion.
If one is commanded under Compulsion to commit an action that is an innermost desire, the command will persist for the remainder of that person's life. Conversely, the weaker forms of Compulsion have no effect on a person who is currently holding the One Power.
Compulsion can be placed on a person permanently as well. By leaving the weaves tied off on a person's mind, their orders or even entire thoughts can be left by the channeler to stay with them until it is either lifted or they die. The more complex the Compulsion weaves, the harder it is to remove them. Lesser Compulsion can be lifted by an experienced enough channeler. However, extremely complex weaves literally end up taking the place of one's mind, rather than manipulating it, so lifting them evidently results in brain damage or death.
Compulsion is used extensively by Graendal, and to a lesser extent by all followers of the Shadow with the ability to channel. Since strong use of Compulsion can completely remove a person's free will, it is forbidden from use by the current Aes Sedai.
It is often found that novices with the spark will have learned some crude form of Compulsion before coming to the White Tower. Normally, this type of Compulsion is simply an unintended prod on another person's mind in order to get something that they strongly want. These women are strongly disciplined and discouraged from using it again.
Recently, Nynaeve al'Meara was able to learn how to work with those under Compulsion. She was able to lift extremely heavy weaves from the mind of one of Graendal's victims. The youth was able to regain his mind for just a few moments in order give Rand and Nynaeve vital information before dying.
The female weave for Compulsion as used by Moghedien is described by Nynaeve as "a complex weave of Spirit streaked by Water and Air". The weave that she lifted from the aforementioned youth also consisted of these elements. A weaker form of Compulsion that Verin has discovered uses all five elements.
Forsaken known to use Compulsion
Aes Sedai known to use Compulsion
- Verin Mathwin (although her version is mild and requires the subject to supply their own motivation)
- Presumably Theodrin Dabei
- The Blue Ajah (one of their secret weaves is closely related to Compulsion)
- Delana (under Graendal's instructions; by a comment by Graendal it seems that many Black Ajah sisters were instructed in it)