What common characteristic do all common law nations share?

All common law nations share the characteristic of having legal traditions that are fundamentally derived from English common law. This is primarily because many of these nations were colonized by England, which established a legal system that relied on judicial decisions and precedents rather than being strictly based on codified statutes. As a result, the principles and practices of common law, including the role of case law and the doctrine of precedent, were introduced and developed in these countries.

Countries such as the United States, Canada, Australia, and India, among others, adopted this legal framework as they gained independence or were established as colonies of the British Empire. This historical connection to English law has created a commonality in legal practices and principles among these nations, distinguishing them from those that operate under different legal systems, such as civil law jurisdictions that rely heavily on codified laws rather than judicial rulings.