The position to readily placed block fast moving blows to one's vital striking points, down the centerline of the body—neck, chest, belly and groin. Shifting or turning within a stance is carried out variantly on the heels, balls, or middle (K1 or Kidney 1 point) of the foot depending on lineage. As described more below, some Wing Chun styles discourage the use of high kicks, since this creates an opportunity for counter-attacks to the groin. Additionally, the practice of "settling" one's opponent to brace them more effectively against the ground aids in delivering as much force as possible to them.
Softness (via relaxation) and performing techniques in a relaxed manner, is fundamental to Wing Chun. On "softness" in Wing Chun, Yip Man during an interview said,
Wing Chun is in some sense a "soft" school of martial arts. However, if one equates that work as weak or without strength, then they are dead wrong. Chi Sao in Wing Chun is to maintain one's flexibility and softness, all the while keeping in the strength to fight back, much like the flexible nature of bamboo"
The first, and most important form in Wing Chun, Siu Nim Tau, which can be translated into "The little idea for beginning", Siu Nim Tau is not only for beginners but to be practiced throughout the practitioner’s lifetime. It is the foundation or "seed" of the art from which all succeeding forms and techniques depend. Fundamental rules of balance and body structure are developed here. Using a car analogy: for some branches this would provide the chassis, for others this is the engine. It serves basically as the alphabet for the system. Some branches view the symmetrical stance as the fundamental fighting stance, while others see it as more a training stance used in developing technique.
The second form, Chum Kiu, focuses on coordinated movement of bodymass and entry techniques to "bridge the gap" between practitioner and opponent and move in to disrupt their structure and balance. Close-range attacks using the elbows and knees are also developed here. It also teaches methods of recovering position and centerline when in a compromised position where Siu Nim Tau structure has been lost. For some branches bodyweight in striking is a central theme, whether it be from pivoting (rotational) or stepping (translational). Likewise for some branches, this form provides the engine to the car. For branches who use the "sinking bridge" interpretation, the form takes on more emphasis of an "uprooting" context adding multi-dimensional movement and spiraling to the already developed engine.
Biu Ji (Thrusting Fingers)
The third form, Biu Ji, is composed of extreme short-range and extreme long-range techniques, low kicks and sweeps, and "emergency techniques" to counter-attack when structure and centerline have been seriously compromised, such as when the practitioner is seriously injured. As well as pivoting and stepping, developed in Chum Kiu, a third degree of freedom involving more upper body and stretching is developed for more power. Such movements include very close range elbow strikes and finger thrusts to the throat. For some branches this is the turbo-charger of the car. For others it can be seen as a "pit stop" kit that should never come into play, recovering your "engine" when it has been lost. Still other branches view this form as imparting deadly "killing" and maiming techniques that should never be used if you can help it. A common wing chun saying is "Biu Ji doesn't go out the door." Some interpret this to mean the form should be kept secret, others interpret it as meaning it should never be used if you can help it.