One of the main features in Age of Wushu is the inclusion of "internal skills", the way a character grows within the game. These internal skills are based on ancient Chinese culture, also prominently featured in the game.
The second most recognizable school, Wudang, is not as rigid in discipline or style as Shaolin. Their Internal Skill, as well as their studies and practices outside the realm of the game, reflect this ideology. Tai chi is a derivative of Taoism culture, which began atop Wudang Mountain many years ago (before the time Age of Wushu takes place). The Yin Yang Protecting Skill flows like the movements of Tai chi practitioners today. It is the water-like representation of the balance between Yin and Yang. This skill uses a combination of forward and backward attacks to affect an enemy, rather than the rough punches from the Shaolin.
Read more on the Age of Wushu site.