The Lex Plautia Papiria de Civitate Sociis Danda was a Roman plebiscite enacted amidst the Social War in 89 BCE. It was proposed by the Tribunes of the Plebs, M. Plautius Silvanus and C. Papirius Carbo. The law granted Roman citizenship to Italian communities that had previously rebelled against Rome during this war.
The Social War, which was fought between 91 and 88 BCE, was a rebellion against Rome by some of her Italic socii (allies) caused by Rome's refusal to grant them Roman citizenship. However, this concession became necessary to try to stem the rebellion. The Lex Plautia Papiria was not the first law that extended Roman citizenship during the Social War. In 90 BCE, the Lex Calpurnia gave commanders the power to reward valor of soldiers with Roman citizenship. In the same year, the Lex Julia de Civitate Latinis et Socii Danda granted civitas to Italian communities who had not participated in the rebellion against Rome to prevent them from joining the war. The law stated that communities with newly granted citizenship should be enrolled in new tribes for voting in the Comitia Tributa. In 89 BCE the Lex Plautia Papiria followed the guidelines laid out in the Lex Julia for adding new tribes to the Comitia Tibuta for the new communities which were also granted citizenship. In the same year, the Lex Pompeia de Transpadanis granted Latin rights to the communities in Transpadana, the region north of the River Po as a reward for having sided with Rome during the war.
While the complete original text of the law has never been recovered, Cicero stated several of the provisions of the law in his Pro Archia Poeta Oratio:
The freedom of the city was given him in accordance with the provisions of the law of Silvanus and Carbo: "If any men had been enrolled as citizens of the confederate cities, and if, at the time that the law was passed, they had a residence in Italy, and if within sixty days they had made a return or themselves to the praetor."