Ki

Ki or energy, is the life force energy of all living things. This force is tangible energy inside every living being, with its major focus being in the center of the body. By drawing it out, an individual is able to manipulate it and use it outside their body which can be used for many different techniques. Because there are physical limits to the strength of the body itself, it is necessary to increase one's ki to overcome this barrier and become stronger. Usually, the more concentrated the masses are, the more time the user requires to draw it out by powering up. When fighters gather energy, they are able to gain enhanced strength, speed, endurance, and can increase the power of their attacks to inflict greater damage to opponents. Normally, the more the ki is increased, the harder it is to control, so ki control is also important. Energy can be lost when the user sustains injuries or transfers energy to an ally.

Types

 * Good ki: Energy that holds no evil intentions. The appearance of this ki is usually a white aura around the user though some techniques and transformations can change the appearance of this type of ki.
 * Evil ki: Ki that is manifested by beings with evil hearts. This nature of ki can be changed if the user holds no evil intentions. The appearance of this type of ki is usually a purple or pink aura around the user. However, users who have such dark and intense, evil ki can corrupt other beings into becoming evil as well.
 * Godly ki: A special type of ki used by godly beings. Godly ki is far superior to regular ki, however, a large enough amount of regular ki can outmatch a Godly ki. The appearance is different depending on the user.
 * God of Destruction ki: Gods of Destruction have a special type of Godly ki fueled by their own Energy of Destruction. The appearance is that of purple aura outlining the user.
 * Evil Godly ki: A type of ki that combines the properties of Evil and Godly ki and the appearance of this type of ki is a black aura around the user.

Amounts
The amount of ki varies depending on the individual. Usually, non-trained beings have very little ki. Training can increase the amount of ki greatly. The amount of ki is generally related to the Power Level, the greater the amount of ki, the greater the power level of the user.

Although Godly ki is clearly superior to regular ki, potent enough regular ki can rival it..

If the ki is great enough it can affect the surrounding, like generating powerful gusts of wind, shaking the ground (even the planet) or even destroying it.

In order for someone to be able to take attacks from a foe without taking any damage, they must possess twice the power of their foe.