At its heart, coin casting translates the heads or tails of three coins into yin and yang lines. Traditionally, the side with writing (the "text face") is considered yin, and the blank or patterned side (the "reverse side") is yang—but different schools may define them differently, so decide your own rule before you begin and stick with it. Each toss of three coins produces one of four results based on the number of heads/tails: "old yin," "young yin," "young yang," or "old yang." The "old" lines are moving lines, indicating change. This logic comes straight from the I Ching's philosophy of yin and yang as forces of transformation in the universe—the coins are simply a medium for those symbols. Ancient practitioners believed the randomness of the toss could reflect the present moment and the querent's state of mind, serving as a tool for contemplation, not absolute fortune-telling.

Before tossing, clear your mind and focus on a specific question—make it concrete. Hold the three coins loosely in your palms, then gently toss them onto a flat surface like a table or tray. The result of this first toss gives you the "first line" (called the initial line). Repeat this process six times total, and record each line from bottom to top: lines 1 through 6. Each line is determined by the heads/tails combination (yin or yang, and note whether it's a moving line). After all six tosses, you'll have a "primary hexagram." If any line was moving, flip its yin/yang to derive a "relating hexagram." The primary hexagram shows your current situation; the relating hexagram suggests how things may evolve. Together they offer a fuller picture.

Once you've cast all six lines, write them down clearly in order (bottom to top) with their yin/yang label and any moving lines marked—this prevents confusion later. After you have both the primary and relating hexagrams, consult the names, judgments, and line texts of the 64 hexagrams. Beginners can start by looking at the overall imagery of each hexagram—what atmosphere or situation does it evoke? Then zoom in on any moving lines, as they often carry key messages. Remember, I Ching coin casting is meant to inspire reflection and self-understanding—it's cultural and entertainment insight, not medical, financial, or legal advice. Use it wisely and you'll truly appreciate the beauty of the I Ching.