Universal Law is a common term for laws that are universally accepted throughout all realms. Some of the common offenses that fall under Universal Law include Emblem Fraud and Haers Theft. More commonly, though, it refers to the system of legal philosophy that is used by courts to make determinations of innocence or guilt, and to exact punishment accordingly. The system has been in use for some couple hundred years, and is specifically designed to limit intervention by the courts (the concept of "victimhood" is skewed such that almost any action against an entity that was not prevented by that entity is considered implicit; in other words, if you did nothing to prevent it, or were not able to prevent it, then you chose to do nothing or to limit your abilities in such a manner as to be able to prevent it). Almost every court case is just a matter of arguing whether or not one is actually implicit. This concept is called the Allowance Law.
Cases of fraud are almost always dismissed, for example, as are thefts of property outside of specific circumstances (haers theft, and marketplace theft are examples). In other, not so blatant cases, for example, a man may be attacked by another. He is beaten, knocked out, and subsequently robbed. A court would likely dismiss this case because, due to Allowance Law, he allowed himself to be beaten and then robbed. In the court's eyes, he made the choice not to prepare himself for such a circumstance. It is considered negligence. However, the same case might be chosen in favor of the victim, for instance, if he could establish some circumstance beyond control which prevented him from being able to avoid such an encounter. An example might be if the man had previously contracted some unavoidable illness, which impaired his ability to act in his own defense.
Because Allowance Law is so tenuous from a philosophical standpoint, much of the argumentation in court eventually boils down to another legal concept, which is from antiquity: Convincement Law. This is simply when one's argument only needed to be sufficient in order to convince the adjudicator, in most cases a head of state or his representative (King, Crownprince, Magistrate, tribunal, etc.).