Wu Hun Dao (Way of the Martial Spirit in Mandarin), is Sifu Jason Goldsmith’s personal method of Wun Hop Kuen Do (WHKD). WHKD Kung Fu, which means "combination fist art style", was founded by Sifu Al Dacascos in 1969. Wun Hop Kuen Do (WHKD) is a style of KAJUKENBO that incorporates Chinese and Filipino martial arts into the traditional KAJUKENBO system. KAJUKENBO is a composite system of martial arts that was formed between 1947-1949 by grandmasters from various forms of martial arts. Mr. P.Y.Y. Choo brought karate to the system (KA). Mr. Frank Ordonez brought Ju-Jitsu, while Mr. J. Holck contributed Judo (JU-JU-Jitsu). Professor Adriano D. Emperado, the only remaining founder of the system, contributed Kenpo (KEN), as well as the Filipino fighting arts. Professor C. Chang contributed the boxing (BO) aspects of the art, including both western boxing and Chinese boxing, more commonly called Kung Fu.

As a composite system, KAJUKENBO sought to adapt and combine martial arts styles to create an all-inclusive system that could be effective in any street scenario. Sifu Al Dacascos took this further, incorporating significantly more Kung Fu elements into the system, as well as additional Filipino knife and stick fighting (known as Kali, Arnis, or Escrima). He further modified the system by incorporating 25 unique fighting principles to help consolidate combat knowledge into a common language that can be discussed and referred to in class. Finally, Sifu Al Dacascos further emphasized practically in his style, resulting in a system that prides itself on being reliable and practical in real-life encounters.

WHKD is commonly referred to as a "system without a system". The art seeks to adapt to any situation and incorporate new techniques and methodologies as they are encountered by practitioners. Within this framework, the style still maintains it traditional roots in Kung Fu, teaching the "ways to preserve rather than destroy", and seeking to instill a respect for humankind and sense of calm that should be present in any true martial artist.

Traditional WHKD instruction is based around a set of requirements: blocks, strikes, holds, locks, throws, combinations, setups, history, and fighting principles that are contained in a red binder affectionately referred to as the "Redbook". The Redbook contains the list of requirements needed for each rank in the system. Next to each listed requirement is a description of the technique, to aid the student in study outside of class, and a place where the instructor may "sign off' the technique--a form of evaluation used to determine whether the technique is performed by the student at a level suitable for testing. When all the requirements of a given rank are signed off, the student may test for the next belt. The ranking system in WHKD is: white, yellow, orange, purple, blue, green, brown, and degrees of black. Red belts, which signify assistant instructor, may also be given out under certain circumstances.

Classes at Goldsmith Kung Fu and Mixed Martial Arts are based on the core WHKD requirements, but goes further to emphasize street-based applications of those requirements; teaching how to adapt the techniques learned to a variety of situations, and learning how to be spontaneous when fighting--using the requirements as building blocks instead of canon. Finally, the classes also add an extra element of grappling, building upon the foundation of Judo and Ju-Jitsu that is present in the system.