In martial arts, the terms hard and soft technique denote how forcefully a defender martial artist counters the force of an attack in armed and unarmed combat. In the East Asian martial arts, the corresponding hard technique and soft technique terms are 硬 (pinyin yìng, Japanese gō) and 柔 (pinyin róu, Japanese jū), hence Goju-ryu (hard-soft school), Shorinji Kempo principles of go-ho ("hard method") and ju-ho ("soft method"), Jujutsu (“art of softness”) and Judo (“gentle way”).
Regardless of origins and styles "hard and soft" can be seen as simply "opposing or yielding"; each has its application and must be used in its own way, and each makes use of specific principles of timing and biomechanics.
In addition to describing a physical technique applied with minimal force, "soft" also sometimes refers to elements of a discipline which are viewed as less purely physical; for example, martial arts that are said to be "internal styles" are sometimes also known as "soft styles", for their focus on mental techniques or spiritual pursuits.
The soft technique usually is applied when the attacker is off-balance, thus the defender achieves the "maximum efficiency" ideal posited by Kano Jigoro (1860–1938), the founder of judo. The Taijiquan (T'ai chi ch'uan) histories report "a force of four taels being able to move a thousand catties", referring to the principle of Taiji — a moving mass can seem weightless. Soft techniques — throws, armlocks, etc. — might resemble hard martial art techniques, yet are distinct because their application requires minimal force.
In Judo and Jujutsu when the attacker (uke) pushes towards the defender (tori), the tori drops under the uke, whilst lifting the uke over himself, effecting the Tomoe Nage throw with one of his legs. The technique is categorized as a "front sacrifice technique" in judo and jujutsu styles. The push from the uke can be direct, or it can be a response to a push from the tori.
With martial arts styles such as T'ien Ti Tao Ch'uan-shu P'ai the soft style is also in keeping with the Taoist philosophy, the idea that the technique can also be applied in mental terms as well as physical.
Soft techniques can be used in offense but are more likely to appear in defense and counter offense. Much like hard techniques they are effected by foot work and skeletal alignment. Where a hard technique in defense often aims to interrupt the flow of attack; a soft technique aims to misdirect it, move around it or draw it into over commitment, in counter offense a soft technique may appear as a slip or a vault or simply using the momentum of a technique against the user. Soft techniques in offense would usually only include feints and pulling motions but the definition and categorization may change from one art form to another.
Soft techniques are also characterized as being circular in nature and considered internal (using Qi (Chinese) or ki (Japanese and Korean)) by martial arts such as tai chi chuan, hapkido and aikido.