Law
Custom and tradition are practices that are widely adopted and agreed upon in a society, thought often not in a written form. Custom and tradition can be enforced in courts and are sometimes considered as part of the legal reasoning in matters decided in courts. In some societies and cultures all law is or was custom and tradition, though this is increasingly rare although there are some parts of the world where custom tradition are still binding or even the predominant form of law, for example tribal lands or failed states.