The Art was only taught to members of the Chen clan until a promising young outsider named Yang Lu Chan was accepted as a student in the early part of the 19th century. Yang Lu Chan (nicknamed "Yang without enemy" as he was reportedly a peerless fighter) modified the original Chen style and created the Yang style of T'ai Chi Ch'uan, the most popular form practiced in the world today. Wu Yu Hsiang leaned the Art from Yang Lu Chan and a variation of the original Chen form from Chen Ching Ping (who taught the "small frame" version of Chen T'ai Chi Ch'uan) and created the Wu style. A man named Hao Wei Chen learned the Wu style from Wu Yu Hsiang's nephew and taught the style to Sun Lu Tang, who in turn created the Sun style (Sun was already an established master of Hsing Yi Chuan and Pa Kua Chang when he learned T'ai Chi Ch'uan. He combined his knowledge of the other arts when creating his style). Yang Lu Chan had another student, a Manchu named Ch'uan You, who in turn taught the Art to his son, Wu Jian Ch'uan. Wu Chian Ch'uan popularized his variation of the Yang style, which is commonly referred to as the Wu Chian Ch'uan style. In recent times (this century) there have been many other variations and modifications of the Art, but all may be traced back through the above masters to the original Chen family form.

Traditionally, single patterns of movement were learned and repeated over and over until mastered, only then was the next pattern taught. Once the student had mastered an entire sequence of movements individually, the movements were taught in a linked sequence (a 'form'). The goal of training is to cultivate a kind of 'whole body' power. This refers to the ability to generate power with the entire body, making full use of one's whole body mass in every movement. Power is always generated from 'the bottom up', meaning the powerful muscles of the legs and hips serve as the seat of power. Using the strength of the relatively weaker arms and upper body is not emphasized. The entire body is held in a state of
dynamic relaxation which allows the power of the whole body to flow out of the hands and into the opponent without obstruction.

The T'ai Chi Ch'uan arts have a variety of two person drills and exercises designed to cultivate a high degree of sensitivity in the practitioner. Using brute force or opposing another's power with power directly is strictly discouraged. The goal of two person training is to develop sensitivity to the point that one may avoid the opponent's power, and apply one's own whole body power where the opponent is most vulnerable. One must cultivate the ability to 'stick' to the opponent, smothering the others' power and destroying their balance. Finally, the formal combat techniques must be trained until they become a reflexive reaction. Modified forms of T'ai Chi Ch'uan for health have become popular worldwide in recent times because the benefits of training have been found to be very conducive to calming the mind, relaxing the body, relieving stress, and improving one's health in general. 

Modern vs. Traditional training methods 

Traditionally, a beginning student of Tai Chi Chuan was first required to practice stance keeping in a few basic postures. After the basic body alignments had settled in, the student would progress to performing single movements from the form. These were performed repetitively on a line. After a sufficient degree of mastery had been obtained in the single movements, the student was taught to link the movements together in the familiar long form. Now, it is not uncommon for a student to be taught the long form immediately, with no time being spent on stance keeping or on basic movement exercises. Since the Long Form trains all of the qualities developed in the basic exercises, this does not really produce a dilution of resulting martial art. It does however make it more difficult for beginner to learn. The duration of the basic training depends on the student and the instructor; however, it would not be unusual for a relatively talented student, with good instruction, to be able to defend themselves effectively with Tai Chi after as little as a year of training.

The Yang style of T'ai Chi Ch'uan is a variation of the original Chen style. The forms, which were passed down from the Yang style founder, Yang Lu Chan have undergone many modifications since his time. Yang Lu Chan's sons were very proficient martial artists and each, in turn, modified their father's art. The most commonly seen variation of the form found today comes from the version taught by Yang Lu Chan's grandson, Yang Cheng Fu. It was Yang Cheng Fu who first popularized his family's Art and taught it openly. Yang Chen Fu's form is characterizes by open and extended postures. Most of the modern variations of the Yang style, as well as the standardized Mainland Chinese versions of T'ai Chi Ch'uan, are based on his variation of the Yang form. 

Yang Lu Chan's student, Wu Yu Hsiang combined Yang's form with the Chao Bao form, which he learned from Chen Ching Ping, to create the Wu style. This style features higher stances and compact, circular movements. His nephew's student, Hao Wei Chen was a famous practitioner of the style, so the style is sometimes referred to as the Hao Style. Hao Wei Chen taught his style to Sun Lu Tang, who combined his knowledge of Hsing Yi Ch'uan and Pa Kua Chang to create his own 

Yang Lu Chan had another student named Chuan You, who in turn taught the style to his son Wu Chian Ch'uan. This modification of the Yang style is usually referred to as the Wu Chian Chu'an style. This form's movements are smaller and the stances are higher than the popular Yang style. 

In summary, the major styles of traditional T'ai Chi Ch'uan are the Chen, Yang, Wu, Wu Chian Ch'uan and Sun. All other "styles" are variations of the above. 

Non-martial Tai Chi variants. 

There are modified forms of Tai Chi which are devoted mostly to health enhancement and relaxation. The movements retain the flavor of Tai Chi Chuan, but are often simplified.