• The Luban Book (《鲁班书》), also known as Que Yi Men (《缺一门》, “The Missing One Gate”),

1. • The Luban Book (《鲁班书》) is an ancient Chinese text attributed to Lu Ban (鲁班), a legendary carpenter, inventor, and engineer of the Spring and Autumn Period (770–476 BCE).
   • It combines practical craftsmanship (carpentry, architecture) with esoteric knowledge (Feng Shui, Daoist mysticism, and folk rituals).
2. Content Structure
   • Volume 1: Practical Techniques
     • Detailed woodworking methods, tool designs, and architectural principles (e.g., mortise-tenon joints, beam structures).
     • Examples: Temples, furniture, and traditional Chinese wooden buildings.
   • Volume 2: Mystical Teachings (allegedly)
     • Contains charms, spells, and rituals tied to construction (e.g., ensuring structural stability or cursing opponents).
     • The title Que Yi Men (“Missing One Gate”) reflects a folk belief that mastering the book leads to personal sacrifice—prosperity in skill but loss in family, health, or fortune.
3. Cultural Significance
   • Historical Influence: Shaped Chinese carpentry and architecture; some techniques remain in use today.
   • Legends & Taboos:
     • Lu Ban allegedly hid advanced knowledge to prevent misuse, leading to the “curse” tradition.
     • Practitioners were said to face the “missing one” (缺一) fate—success in craft but suffering in another life aspect.
   • Daoist & Folk Connections: Linked to Fangshi (方士, occult traditions) and rural superstitions.
4. Controversies
   • Authenticity Debate: Scholars question whether Volume 2’s mystical content was added later or distorted by folklore.
   • Forbidden Knowledge: Some dynasties banned the book due to fears of its alleged supernatural power.
5. Legacy
   • Lu Ban is worshipped as the god of builders in Chinese folk religion.
   • The text symbolizes China’s historical interplay of empirical skill and spiritual belief.
   • Modern adaptations focus on its technical heritage, while mystical elements remain a cultural curiosity.

Key Note: Que Yi Men underscores the book’s dual reputation—a treasure of craftsmanship and a cautionary tale about hidden knowledge.