In short Hap Ki-Do means the art of power coordination.

The coordination of power is manifested in two ways: first and most important is the harmony between the mind and body. To be able to function most effectively in a combat situation, one must have control of both mind and body. You should use the body as an extension of your mental directives. The second concept of harmony deals with the coordination of an attack or defense. Both concepts are essential to good self-defense. A person might know how to save himself from a knife attack, but if he allows fear to effect his body then all his knowledge is in vain. Likewise a person may be totally calm, in full control of his emotions and body; however if he is unable to use his opponent's force against him then he will be at a disadvantage.

The Koreans describe this harmony or coordination of power on a deeper, more philosophical level. Being greatly influenced by Buddhism and Taoism, they feel that Hap Ki-Do is a way of becoming one with nature.

The most important element in Hap Ki-Do and one of the most difficult to develop is the power of mind. The basis for mental power is Ki. Ki is an oriental concept of the power in all nature all around us. It is said that all living things posses Ki in varying intensities.

Although Hap Ki-Do is primarily defensive in nature, it can be very offensive when the need arises. Many of its techniques are based upon an opponent's attack. Once the attack has been nullified, a devastating counterattack is launched. Hap Ki-Do not only meets the attack, but quickly and effortlessly disables the attacker by reversing their own force and using it against them.

Self-control is crucial in combat situations. For example, one would react differently to a drunken friend at a party than to an unknown attacker in a dark alley. In the first situation, one would want to constrain the friend so that they are not harmed. In the second situation, one might have to disable or kill the unknown attacker. There are many levels of harshness in Hap Ki-Do techniques and many measures of control and variation for each technique.