The 3 coin method is the most common method. Heads or tails are interpreted as Yin or Yang respectively. Some prefer heads to be interpreted as Yang, and you can change this in the Settings app. Each coin has an equal probability of being heads or tails. 3 coin line probabilities are:
- 6, greater changing yin, is 1 in 8
- 7, lesser yang, is 3 in 8
- 8, lesser yin, is 3 in 8
- 9, greater changing yang, is 1 in 8
The Yarrow stalk method is preferred by more serious students of the I Ching. This involves separating yarrow stalks and counting them, which takes more time, enabling you to meditate upon your question. Yarrow stalk line probabilities are:
- 6, greater changing yin, is 1 in 16
- 7, lesser yang, is 5 in 16
- 8, lesser yin, is 7 in 16
- 9, greater changing yang, is 3 in 16
The 4 coin method is relatively new, and has the same probabilities as the yarrow stalk method. In this method, each coin represents a binary value, either 0 or 1, 0 or 2, 0 or 4, or 0 or 8, and summing these produces a numeric value from 0 to 15. This is then used to determine the line value from the yarrow probabilities.
The Quick method generates yin or yang lines with equal probability, and only one changing line by default. This can be changed to use 3 coin or yarrow stalk probabilities in the Settings app.
The 3 Dice method is devised by Michael Hurn, and is described in more detail in his book, “I Ching: the book to turn to for Wisdom and Guidance,” available for additional in-app purchase.
The Circle of Protectors method is devised by Stephen Karcher, and is described in more detail in his book, “Navigating Change,” available for additional in-app purchase.
The Mandala method is devised by Michael Tingle, and is described in more detail in the default book translation, as well as on this web site: http://www.michaeltingle.com/apps/.
Some oracle methods, such as 3 Coin and Yarrow, may produce no changing lines, or multiple changing lines. When no changing lines are produced, Changes and Future tabs do not display any text. However, the Future tab provides a link to the Mutual (or Nuclear) hexagram, whose reading may indicate hidden potential for the situation.
See the section for Settings options to control the display of lines text when there are multiple changing lines.