Law is not just statutes; it is the "Operating System" of society. As the world enters the era of AI and high-frequency trading, traditional legal logic is struggling to keep up. How do we govern a world where algorithms update in seconds, but legislation takes years? "Legal Governance: Boundaries, Systems, Protocols, and Intelligent Governance" proposes a boundary-centered theory for the digital age. Ng Tick Kee argues that law must evolve from "managing behavior" to "managing systems." Core Insights: The Behavior Boundary Model: A new classification system (Permitted, Regulated, Prohibited) to clarify legal risks in complex environments. Governance Protocols: How to create an "institutional syntax" that coordinates behavior across platforms, communities, and jurisdictions faster than statutes can. Hybrid Governance: The future order is not maintained by law alone, but by the collaboration of Law, Platforms, Technology, and Communities. Agentic Governance: Preparing for a future where AI agents participate in decision-making. How do we design a "human-AI co-governance" framework? This is a blueprint for the architects of future order. Whether you are a lawyer, a policymaker, or a tech regulator, this book offers the structural language needed to understand and design governance in a cross-domain, automated world.