The "Law of Unintended Consequences" refers to the idea that actions, especially those taken with good intentions, can lead to unexpected and often negative outcomes. This concept highlights the complexity of systems where changes can produce results that were not anticipated by the decision-makers. For example, when governments implement new policies to improve public health, such as banning certain substances, it may lead to unintended consequences like the rise of black markets. Understanding this law encourages careful consideration and analysis before making decisions, as the effects can ripple through society in unforeseen ways.