JKD is based on three main principles: simplicity, directness, and being non-classical. With these ideals in mind it is easy to comprehend how effective JKD can be.

Simplicity is not a new concept. Anyone that knows anything about mechanics, realizes that simplicity is what makes things work. Mechanically, the more complicated the machine, the more moving parts it has. With more moving parts, the odds of failure become greater. The human body is no different. Accumulation of techniques only adds complications. Excess movement leaves a greater possibility for inaccuracy. Being simple in structure, JKD only has approximately five punches and four kicks. These few tools, as we call them, are broken down and practiced to the point in which they are extremely efficient. Centering oneself on these few techniques best utilizes the short amount of time a normal human being has in which to perfect them. A person with a great propensity towards athletic performance, may be able to adequately perform a technique in a short amount of time. Even though their performance may be adequate it is far from perfection. Perfection is execution without a single flaw. To reach this stage of development takes a life time, no matter how much natural ability one has. If Bruce were alive today, he would be the first to tell you that even he, himself, was far from perfection. That is one of the many things that made him so incredible. He never settled for mere adequacy Adding excessive techniques to ones arsenal only adds to the amount of time to reach that perfection. If it takes a life time to perfect one punch, how long will it take to perfect a barrage of techniques borrowed from Silat, Thai boxing, Jui- Juitsu etc? It is obviously a complete impossibility in one life time. How many lives do we have?

Directness goes hand in hand with simplicity. A direct approach to self improvement is an approach that is exact, concise, and straight forward. Keeping this in mind, we can appropriate the techniques in JKD. JKD is based on a straight line. A line, being the shortest distance between two points, is the most logical path due to its speed and efficiency. A hooking attack generates power through momentum. A straight attack is power because it arrives there first, nullifying any other attack. In being direct, no excess motion is exerted. For example, If an assailant grabs your wrist, some forms of martial arts may teach you to stomp on their foot, grasp their hand, take them down to the ground with a wrist lock, subdue them with an arm bar, and then finish them with a strike to the throat. This seems brutal and may appease the misinformed. In reality, it is complicated, indirect, and a complete waste of energy. The direct solution would be to strike them in the throat right off the bat. No need for theatrics.

JKD is not a classical system. By this I mean, practitioners do not wear uniforms, they do not practice forms, and they don't waste time with techniques simply because of tradition. Many martial artist attest that their system is effective because it is hundreds of years old. Age and tradition have absolutely nothing to do with efficiency. Hundreds of years ago people were bled with leaches to cure the flu. Does this mean we should do the same?

Bruce, being a philosopher as well as a martial artist made many statments such as the on above that related to his thoughts on JKD. It is unfortunate that many of his writings have been misinterpreted since his death. Some have so badly been misconstrued that the opposite meaning has been accepted as the truth.

You should be able to adapt to the situation at hand. As an attack approaches, you are ready with the appropriate response. The opponents attack becomes your attack, as you fit into the opening created. He states that JKD can "fit in with any style". This does not mean that JKD can be added to any style to make it more efficient, or vice versa. What it does mean is that JKD can counter an adversary regardless of their style or system. It fits in, filling the gaps left by their commitment to attack. JKD uses any means necessary to accomplish this task. If grabbed you may bite, scratch, or pull hair. If kicked you may kick back, punch, eye jab, or what ever best fits the situation. JKD is not limited to only punching, or only kicking. It is fighting with any ability you may have.

JKD does not need to borrow or adapt techniques from other styles to achieve its means. Along with the philosophy, Bruce developed extremely effective ways of attacking, moving, and defending yourself. Without knowledge of his methods, the practice of true JKD is impossible. He spent his lifetime researching, through trial and error, the most efficient ways a human body can perform.