Roman law is the legal system of ancient Rome and the legal developments spanning over a thousand years, from the to the Corpus Juris Civilis (AD 529) ordered by Eastern Roman emperor Justinian I. The historical importance of Roman law is reflected by the continued use of Latin legal terminology in legal systems influenced by it.

After the dissolution of the Western Roman Empire, the Justinian Code remained in effect in the Eastern empire, known in the modern era as the Byzantine Empire (331–1453). From the 7th century onward, the legal language in the East was Greek.
"Roman law" also denotes the legal system applied in most of Western Europe until the end of the 18th century. In Germany, Roman law practice remained in place longer under the Holy Roman Empire (963–1806). Roman law thus served as a basis for legal practice throughout Western continental Europe, as well as in most former colonies of these European nations, including Latin America, and also in Ethiopia. English and North American common law were influenced also by Roman law, notably in their Latinate legal glossary  Eastern Europe was also influenced by the jurisprudence of the Corpus Juris Civilis, especially in countries such as medieval Romania (Wallachia, Moldova, and some other medieval provinces which created a new system, a mixture of Roman and local law. Also, the Eastern Europe law was influenced by the "Farmer's Law" of the medieval Byzantine legal system.
In other words the Roman law was very famous all around the world everyone liked the Romans systems so they passed it to their own country
Another important statute from the Republican era is the Lex Aquilia of 286 BC, which may be regarded as the root of modern tort law. However, Rome's most important contribution to European legal culture was not the performing of well-drafted statutes, but the emergence of a class of professional jurists and of a legal science. This was achieved in a gradual process of applying the scientific methods of Greek philosophy to the subject of law, a subject which the Greeks themselves never treated as a science.
Traditionally, the origins of Roman legal science are connected to  Flavius. Flavius is said to have published around the year 300 BC the formularies containing the words which had to be spoken in court to begin a legal action. Before the time of Flavius, these formularies are said to have been secret and known only to the ministers. Their publication made it possible for non-priests to explore the meaning of these legal texts. Whether or not this story is credible, jurists were active and legal treatises were written in larger numbers the 2nd century BC. Among the famous jurists of the republican period are Quintus Mucius Scaevola who wrote a voluminous treatise on all aspects of the law, which was very influential in later times, and Servius Sulpicius Rufus, a friend of Marcus Tullius Cicero. Thus, Rome had developed a very cultured legal system and a refined legal culture when the Roman republic was replaced by the monarchical system of the principate in 27 BC

I think the Roman system is a really smart law because of this law Rome and the other provinces have rules that the people needs to obey it and if they don’t they will have a big punishment.