The legal systems of the world are so different and complex it is nearly impossible to explore the laws of each country individually. However, many common legal problems arise in global business.

Four common heritages form the bases for the majority of legal systems throughout the world. The differences are more than theoretically important because due process of law varies considerably among and within these legal systems.

Common Law is based on tradition, past practices, and legal precedents set by the courts through interpretations of statutes, legal legislation, and past rulings. Ownership is established by use. The person who can establish first use is considered the rightful owner. Common law is English in origin and is found in the United States and other countries with a strong English influence (previous English colonies).

Code Law is based on a comprehensive system of written rules (codes) of law and is divided into commercial, civil, and criminal codes. Ownership is determined by registration. The first person to register a trademark or other property right is considered the rightful owner. Certain agreements may not be enforceable unless properly notarized or registered. Code law is predominant in Europe and countries influenced by the French, German, or Spanish systems.

Islamic Law is derived from an interpretation of the Koran. Islamic law defines a complete system that prescribes specific patterns of social and economic behavior for all individuals. While the primary objective of the Islamic system is social justice, it also includes property rights, economic decision making, and types of economic freedom. This law is found in Pakistan, Iran, Saudi Arabia, and other Islamic states.

Islamic law prohibits the payment of interest. This prohibition impacts banking practices severely. Some Islamic banks, however, have developed a method of financing trade through the purchase and subsequent sale of stock.

Since the laws are based on interpretation of Islamic law, the international trader must know and understand the way the laws are interpreted in each region. Regional courts may interpret Islamic law from the fundamentalist viewpoint or liberal viewpoint. Local authorities in one region may be willing to allow interest payment, while in another region, all interest charges are deleted and replaced with comparable "consulting fees." In yet another region, authorities may void a contract and declare any interest payments illegal.

Socialist Laws are based on the fundamental tenets of the Marxist-socialist state and center on the concept of economic, political, and social policies of the state. This type of law is found in some of the independent states of the former Soviet Union, in China, and in other Marxist-socialist states. Laws governing ownership, contracts, and other business entities have been created in an attempt to reconcile differences between socialist law and the common or code law that exists in most of the industrialized world.