It’s the unwritten rules that arguably most influence the culture of organizations. And organizational culture spills over into customer experiences. What is not necessarily clear is where the unwritten rules come from. In many—if not most—instances, they are a reaction to the written rules. Sometimes the influence is constructive. When the written rules are bureaucratic, unthinking or unfeeling, the unwritten rules and resulting behaviours can also be subversive. And sometimes they’re just destructive.