What legal tools did the roman republic use to uphold the rule of law

Creation of the law of the Twelve tables was the ancient legislation that was the foundation of Roman law. These laws were created as result of class struggle between the Patricians and the Plebeians. The Plebeians were the "common" citizens of Rome, not wealthy or of nobility as the Patricians but also not slaves. To prevent the Patricians from bending rules and exploiting them, the Plebeians pushed for the creation of the Law of the Twelve tables. The tables themselves, finalized in mid 5th Century, were pieces of stone with writing carved into them. The main benefit of having laws written down was that no one could change them to suit their whims. Once a law was made public (and carving it into stone was as public as it got), the law was known to everyone. No one could bend the rules anymore but also no one could plead ignorance. If a law was made public, it was everyone's responsibility to know and obey.