Butterfly Knives (Baat Jaam Do)
Wing Chun is an unarmed system of combat, even though it includes the Long Pole (Luk Dim Boon Gwan) and the Butterfly Knives (Baat Jaam Do). Baat Jaam Do means "Eight Chopping/Slashing Knives". The Butterfly Knives are a pair of large knives, slightly smaller than short swords. Historically the knives were also referred to as Dit Ming Do ("Life-Taking Knives"). They are also known as Yee Jee Seung Do ("Parallel Shape Double Knives").
Students are only given the Butterfly Knives form in the last phase of the system. When the student graduates from the Butterfly Knives then he or she has completed the entire system of Wing Chun Kung Fu. In the Butterfly Knives form, there is emphasis and training on footwork, coordinating the two swords, the training of the eyes, your wrist motions, body motions and the double hands. Of course with this comes speed, timing, and power as well as the ability to use the Butterfly Knives themselves and learning how to defeat the Long Pole (Luk Dim Boon Gwan) with Butterfly Knives.
Along with the development of the Wing Chun system, the Butterfly Knives/Swords (Baat Jaam Do) were chosen as a only weapon in the Wing Chun system because the length of the Baat Jaam Do made it easy to conceal. It could be used as an extension of the arms, and they were the most deadly and effective weapons of all. The principle was based on the fact that every defence was accompanied by a counter attack, and every attack was accompanied by a trapping, parrying or immobilizing move of the other sword. This is a very skilful form which, with very good techniques, can be applied with weapons or with empty hands.
The blade length of the Butterfly Swords is approximately that of the forearm, for easy concealment within the sleeves or inside boots, and for greater manoeuvrability to spin and rotate in close-quarters fighting. The Butterfly Sword is usually wielded in pairs. As well, they are usually held side by side within the same scabbard, so as to give the appearance of a single weapon. The sword has also a small cross guard to protect the hands of the wielder, which can be used to block or hook an opponent's weapon. The guard can also be used as a knuckle duster when non-lethal application of the weapon is desired. Traditionally, the blade of a Butterfly Sword is only sharpened halfway, from the middle of the blade to the tip. From the middle down to the handle, the blade is left blunt. This is done so that the unsharpened portion of the blade can be used for blocking without damaging a finely honed edge, and to deliver non-lethal strikes. In Wing Chun, one notable aspect of Butterfly Swords combat is that its principles are the basis for all other weaponry. In theory, any object that can be held in the hands of a Wing Chun practitioner will follow basically the same principle of movement as the Butterfly Swords.
The eight cuts or offensive techniques in the Butterfly Knives/Swords set are: