Lex Annalis was the law which decisively regulated the order of office (cursus honourum) in the Roman Republic. Moreover, it set the minimum age that a Roman citizen must have had to apply for a questorship. The requirement was 26 years of age and 10 years of military service.
According to its provisions, a citizen starting his career as a politician had to first apply for a questorship. After two years, he had the right to apply (optional) for the edilate. Then there were the offices of praetor, consul and censor.
As mentioned, the act also regulated the issue of waiting two years (biennium) after leaving the office of quaestor before running in the next elections. However, this rule did not apply to plebeians who could run for new offices every year.
Lex Annalis was introduced by the people’s tribune Lucius Villius in 180 BCE and was an effective mechanism to limit the arbitrariness and over-ambitious new candidates for the magistracy. In this way, efforts were made to reduce the number of candidates and prevent progressive electoral corruption (ambitus).
Interestingly, the act did its job and was rather rigorously followed until the 1st century BCE.