In 1973, Horst W.J. Rittel and Melvin M. Webber, two Berkeley professors, published an article in Policy Sciences introducing the notion of “wicked” social problems. The article, “Dilemmas in a General Theory of Planning,” named 10 properties that distinguished wicked problems from hard but ordinary problems.

1. 1. There is no definitive formulation of a wicked problem. It’s not possible to write a well-defined statement of the problem, as can be done with an ordinary problem.
   2. Wicked problems have no stopping rule. You can tell when you’ve reached a solution with an ordinary problem. With a wicked problem, the search for solutions never stops.
   3. Solutions to wicked problems are not true or false, but good or bad. Ordinary problems have solutions that can be objectively evaluated as right or wrong. Choosing a solution to a wicked problem is largely a matter of judgment.
   4. There is no immediate and no ultimate test of a solution to a wicked problem. It’s possible to determine right away if a solution to an ordinary problem is working. But solutions to wicked problems generate unexpected consequences over time, making it difficult to measure their effectiveness.
   5. Every solution to a wicked problem is a “one-shot” operation; because there is no opportunity to learn by trial and error, every attempt counts significantly. Solutions to ordinary problems can be easily tried and abandoned. With wicked problems, every implemented solution has consequences that cannot be undone.
   6. Wicked problems do not have an exhaustively describable set of potential solutions, nor is there a well-described set of permissible operations that may be incorporated into the plan. Ordinary problems come with a limited set of potential solutions, by contrast.
   7. Every wicked problem is essentially unique. An ordinary problem belongs to a class of similar problems that are all solved in the same way. A wicked problem is substantially without precedent; experience does not help you address it.
   8. Every wicked problem can be considered to be a symptom of another problem. While an ordinary problem is self-contained, a wicked problem is entwined with other problems. However, those problems don’t have one root cause.
   9. The existence of a discrepancy representing a wicked problem can be explained in numerous ways. A wicked problem involves many stakeholders, who all will have different ideas about what the problem really is and what its causes are.
   10. The planner has no right to be wrong. Problem solvers dealing with a wicked issue are held liable for the consequences of any actions they take, because those actions will have such a large impact and are hard to justify.