Nearly 50% of patients in U.S. hospitals experience some form of harm during their stay, costing the economy $17.1 billion per year. The article proposes three simple rules that hospitals can adopt to reduce patient harm and improve safety: 1) Treat all patients and staff with respect to overcome a poor safety culture, 2) Develop a preoccupation with potential failures in order to prevent them, and 3) Ensure an open and transparent culture where staff are comfortable reporting errors without fear of reprisal. Following these three rules can help transform hospitals into high reliability organizations with improved patient safety.