The Eastern religions are a religion group in Crusader Kings II.
The Indian religions, also called Dharmic religions, form a subgroup within the Eastern religions.
The Eastern religions all originated in South and East Asia and share historical connections.
Non-nomadic rulers following a religion of this group are playable with the 
Rajas of India DLC; 
Jade Dragon DLC only makes Taoist rulers playable.
Features
Indian religions
Indian religions are described in detail on the Indian religions page.
道教
Taoism is a religion and philosophy originating in China which is based on living in harmony with "the Way" (Tao or Dao). Its main theorician is Lao Zi, which left a strong impression over Kong Fuzi (better known as Confucius) and was later deified. Like him, many Chinese mythical figures have become Taoist saints or gods along with their close relatives. The main deities are Yuhuang Dadi, the Emperor of Jade which rules over destiny, Donghua Dijun, Lord of the Eastern Mountain and of afterlife and Xiwang Mu, Mother-Queen of the West and guardian of the peaches of Immortality, which grant an almost divine status to the virtuous and wise ones.
Taoist principles are naturalness, spontaneity, simplicity, detachment from desires, and most important of all, wu wei (i.e. "Doing nothing" = not occupying oneself with/not interfering in the affairs of others). The principle of balance (represented by the yin yang symbol) is also important.
In-game, Taoism is restricted by a lack of special casus belli. However, the stability offered by the absence of a short reign penalty should not be underestimated. With the +2 bonus for Stewardship, it is easier to have a large demesne and to receive more taxes. If your ruler has the Han culture in addition to the Taoist faith, he gets +2 Imperial grace every month towards the Chinese Emperor (if the Emperor is Han and Taoist, which he is over long periods of time) which can be spent on a multitude of useful features to improve the domain and strengthen the ruler. Getting a peace treaty and thus protection from Imperial invasion and military help through an Imperial marriage or Kow-tow is easy for a Taoist Han ruler.
Overall, Taoism offers stability and the option to build tall, i.e. smaller but powerful realms, at the price of fewer offensive options.
Taoism has a unique name for Piety, Te.
Features:
- A combination of stability and economic power
- Ruler gets + 2 stewardship
- No "Short reign" penalty
- Can designate any valid offspring as heir
- Can take up to three concubines
- Holy sites: Jiuquan, Lhasa, Khotan, Gaya and Udabhanda
- Jiuquan: An outpost in the Hexi Corridor which near the Kongtong Mountains, one of the sacred mountains of Taoism (though in fact not so near, about 1000 km apart).
- Lhasa: Location of the Jokhang Temple, the most sacred and important temple in Tibet. Jokhang Temple is related to Songtsen Gampo's wife, Princess Wencheng of the Chinese Tang dynasty.
- Khotan: Location of the Kunlun Goddess, the highest mountain of the Kunlun Range. And Khotan is the main source of the nephrite jade used in ancient China.
- Gaya: This is where the Buddha is said to have reached enlightenment ,and according to a Taoist book called Hua Hu Ching(Classic on converting the barbarians) ,after leaving China to the West, Lao Zi had travelled as far as India, where he had converted—or even become—the Buddha.
- Udabhanda:Seems to be the place where the famous Taoist Qiu Chuji meet Genghis Khan.
- Lhasa, Khotan and Udabhanda are important
Silk Road counties.
- Lhasa, Khotan and Udabhanda are important
- Gets +2 Grace/month if Han, as long as Chinese Emperor is Han and Taoist (invasions can change that): better availability of wide variety of boosts from Emperor
- Can Intermarry with Buddhists, Böns, Manicheans, Zunists and Nestorians
- No Holy War CB or special CB
- No religious head and thus no Great Holy War mechanic
- No holy order
- Can choose a school of thought (out of 3 choices) when reaching 100 Te
- Zhengyi Dao, the Way of Orthodox Unity: National Revolt Risk -2%, Martial +1, Intrigue +1, Diplomacy -2.
- Quanzhen School of Complete Perfection: Build Cost -10%, Build Time -10%, Martial -2, Fertility - 25%, Health +1.
- Shangqing School of Supreme Clarity: Diplomacy +1, Stewardship -2, Learning +3.
Taoism Overview
Taoism is in-game almost absent from the map. The only start dates where it is present is 769, with the Han General Protector ruling over Jiuquan Province, and 867 where the Liao Khaganate rules over Mongolia.
China is the main, and almost only source of Taoist characters in-game. When the Emperor is Taoist, it is not rare to find Taoist courtiers created with Grace Interactions. Often, some of them are granted counties as a reward for their services.
Another source of Taoist rulers is the numerous mercenaries that come from China. The Companies of the Qilin and of the Dragon are the most powerful mercenaries in the Far East and provide a steady flow of Taoist commanders, even when the Chinese Emperor is Buddhist (following a Jurchen invasion, or in 1066) or Tengrist (following a Mongol Invasion). Occasionally, they will try to shape out their own territory, or some of their courtiers will become adventurers.
Adventurers are another important source of Taoist characters and especially rulers. The Tarim Basin and Fergana, due to their proximity to China, will be their main targets. Some of them can succeed, and found their own Taoist principalty.
Finally, some events can create Taoist characters. An opponent of the ruling dynasty can seek refuge in a ruler's court, for instance, or following the payment of a tribute of horses the Chinese can send a trade administrator to a ruler's region.