Six Lines Na Jia is the core method of Wen Wang Gua. "Na Jia" refers to "inserting" Heavenly Stems and Earthly Branches into the six lines. A complete hexagram consists of six lines, from the bottom (First Line) upward (Second, Third, Fourth, Fifth, and Top Line). Each line is not only yin or yang, but also assigned an Earthly Branch and a Five Element attribute. This process is called "assembling the chart." Traditionally, the diviner uses three copper coins tossed six times, recording each toss's yin/yang and old/young status to form the primary hexagram and its changing hexagram. Understanding the judgment of old yin and old yang (which become changing lines) is a fundamental skill for beginners. The precision of the Na Jia method lies in transforming abstract hexagram symbols into an analyzable network of Five Element interactions.

The most important practical step in Six Lines is "assembling the chart." First, based on the hexagram’s palace classification (Eight Palaces), assign Earthly Branches to the lines of the inner and outer trigrams. For example, Qian Palace and Kan Palace each have fixed Na Jia formulas; beginners typically memorize the Eight Palaces chart. Next, compare the Five Element of each line’s Earthly Branch with the Five Element of the hexagram’s palace. Those that generate me become Parents; those I generate become Children; those that control me become Officials; those I control become Wealth; those the same as me become Siblings. This is the arrangement of the Six Relationships. Finally, determine the Shi (Self) line and Ying (Other) line. Shi represents the inquirer themselves, and Ying represents the other party or external environment. Their positions are fixed according to the hexagram structure. Mastering these three steps allows you to complete a basic Six Lines chart.

After completing the chart, interpretation relies on selecting the Yong Shen. Yong Shen is the Six Relationship most relevant to the question. For example, for financial matters, look at the Wealth line; for career or official matters, the Officials line; for children, the Children line; for elders or documents, the Parents line. Once Yong Shen is chosen, observe its strength or weakness in the hexagram — whether it is supported or restricted by the month and day, whether it moves (changes), etc. — to assess the overall auspicious or inauspicious trend. The Five Element interactions (generation and control) are the logical backbone of the entire system. Beginners are advised to memorize the generation and control cycles of Wood, Fire, Earth, Metal, and Water, then practice with real cases step by step. Please note: Six Lines divination is a cultural tradition and entertainment reference; it should not be the sole basis for major life decisions.