Meaning all experience in the Roman army was lost by the end of the fighting. Armies would then gain experiences during their campaigning, until they were disbanded with the end of the war or the campaigning season. The army would undergo extensive training before campaign. It was considered the duty of every physical able man to serve in the army when a campaign was called. The soldiers would be organised into four legions, each legion was raised annually. The soldiers were called through a lot drawing process called the Dilectus. The incumbent consuls would recruit an army when it was needed. The pre-Marius Roman army was organised as a conscript levy of all male citizens, similar to other Poleis especially in Greece. These changes remained principally intact until the downfall of the Roman Empire, but there were structural and administrative adjustments, notably by Augustus and later by Diocletian. As a consequence these reforms had a significant impact on the military supremacy of Rome, as well as unintentionally contributing to the social and political disruption of the Late Republic. Marius also granted citizenship and land to all Roman soldiers. The reforms also put the responsibility of supplying and managing an army in the hands of the general. The reforms revolutionised the Roman military machine, introducing the standardised legionary, the cohort unit and drastically altered the property and weaponry requirements for recruitment. Marius proposed radical alterations with the intention of creating a more professional, permanent and dynamic Roman army. Centuries of military campaigning throughout the Mediterranean and increasing invasions and uprisings across Roman territory had stretched the human and physical resources of the Roman army.
The reforms originated as a reaction to the military and logistical stagnation of the Roman Republic in the late 2nd century BC. The Marian reforms were reforms of the ancient Roman army implemented in 107 BC by the statesman Gaius Marius, for whom they were later named.