Yes and no; its martial aspects are completely, and I mean completely reliant on the manipulation of chi energy. Hence if the style is not COMPLETELY mastered, TRULY mastered, its useless for fighting. It can nevertheless be used to enhance focus, and overall athleticism, especially for OTHER Martial Arts. Paradoxically, Yang Tai Chi is both the weakest AND the most powerful of all Kung Fu styles, if you believe that chi energy stuff. Truly mastering Tai Chi though can take decades.
The Yang Style dramatically changed in the 1900s with its emphasis shifting from life or death combat to health approaches and less hardcore martial art applications. One of the greatest shifts was the increased emphasis on using push hands as a fundamental foundation of the martial components (something not existing as much within the old yang style).Teachers of the Old Yang style are much rarer and hard to come by than those familiar with the New Yang Style, and the subject is extremely misunderstood in most circles.Tai Chi Master Bruce Frantzis has a very good appendix on the subject on pages 337 and 338 of his book "Power Of The Internal Martial Arts" (he was fortunate enough to learn and inherit the lineage of the Old Yang Style from Lin Du Ying).http://wiki.answers.com/How_was_tai_chi_developed
Tai Chi Zero is a martial arts style film created in 2012. Yang ventures to Chen Village to dabble in the arts of tai chi. Villagers were strictly forbidden from teaching outsiders about the most powerful form of tai chi and a man planning to construct a railroad through his village prompted Yang.
Ku style /Yang form Tai Chi.
Im not sure if this is relevant but i was told that if you do a specific set of tai chi movements in the sand by the end of it your feet would have drawn a perfect yin yang in the sand and you would be based in the middle of it tai chi looks slow when done in excercising but could quite possibly be THE most deadliest martial art in the world when done fast.
Ku style Tai Chi does exist, as well as Wu style; and many other styles of Tai Chi. Katara studies Ku style/Yang form Tai Chi, Sun style Tai Chi, and Bikram Yoga.
Ku style is Yang style as taught by Ku Yu Cheung a famous Iron Palm practitioner.
Yang Jwing Ming. has written: 'Advanced Yang Style T'ai Chi Ch'uan'
Jwing-Ming Yang has written: 'The root of Chinese Qigong' -- subject(s): Chi kung 'Yang style taichi chuan' 'Chi Kung for Tai Chi Chuan' 'Shaolin chin na'
All Tai Chi styles have the same essential foundations, and have the same aims or goals for betterment of life and martial ability. They differ in how they execute these foundations. Ku style is also (primarily) known as Guang Ping Yang style which is hard to find in the US. It would definitely be worth learning any style of Tai Chi until you can find someone teaching Guang Ping Yang.
My favorite unique DVD on Yang Style Tai Chi is "Yang Style Fighting Applications" by Bruce Frantzis (you can get it online). If you want a video of the form to copy from and learn, there are actually plenty on Youtube, just search "Yang 24" (that is the simplest, easy to learn, well known form which many references to exist for).
There is no such thing as blocking with chi, but you can improve your chi flow making your blocks and strikes more powerful.
Tai Chi is a very ancient martial art that has been used in China for thousands of years.