In the practice of Six Lines (Liu Yao) divination, the moving line and the changing line are among the most critical elements for interpretation. The moving line refers to the "changing line" (old yang or old yin) that appears during the casting process, representing key turning points in the development of events. Accurately interpreting the moving and changing lines is essential for improving the precision of Six Yao divination.

Identifying a moving line is straightforward: in the three-coin method, when all three coins land on the obverse side, it signifies an old yang (denoted by ○), and when all three land on the reverse side, it signifies an old yin (denoted by ×). The line where an old yang or old yin appears is the moving line. A hexagram may contain one or multiple moving lines, or none at all (a static hexagram).

The moving line represents the trend of change and key factors in a situation. When interpreting, the first step is to focus on the position of the moving line. A moving line in the first position indicates the beginning or foundational level of the matter; the second position suggests internal or nearby factors; the third position signifies a transitional phase; the fourth position points to external or higher-level influences; the fifth position represents the core or leadership; and the top position indicates the final outcome or distant factors.

The changing line is derived from the transformation of the moving line. An old yang changes into a young yin, while an old yin changes into a young yang. The new hexagram formed by the transformation of the moving lines in the original hexagram is called the transformed hexagram. The transformed hexagram represents the outcome or future trend of the situation. The original hexagram reflects the current state, while the transformed hexagram indicates the future direction.

When multiple moving lines appear, the order of interpretation is as follows: first, focus on the primary moving line (the one most relevant to the query), then consider the others. If all six lines are moving, it is called a "six clashes hexagram," signifying intense and rapid changes, often indicating significant upheavals.

Interpreting a static hexagram (one with no moving lines) is unique. A static hexagram suggests that the situation is currently stable, with no apparent trends of change. When interpreting a static hexagram, the focus should be on the strength or weakness of the "use god" (the line corresponding to the query) to determine auspicious or inauspicious outcomes. A static hexagram does not imply no change but rather that change has not yet begun or is in a latent phase.

Mastering the interpretation of moving and changing lines requires extensive practice and experience. Beginners are advised to start with hexagrams containing a single moving line and gradually progress to analyzing more complex configurations. Additionally, it is important to integrate hexagram statements, line statements, and the relationships of the five elements (Wu Xing) for a comprehensive judgment.