Short answers, pulled from the story.
The Roman Senate ratified the Twelve Tables in 449 BC. This text became the oldest surviving record of citizenship rights in ancient Rome and was displayed publicly within the Roman Forum for all citizens to see.
Emperor Caracalla declared all free men within the Roman Empire to be full Roman citizens through the Constitutio Antoniniana in AD 212. Free women received equal rights to those held by Roman women except for specific exceptions while dediticii remained excluded from citizenship.
Non-Romans acquired citizenship status by serving in non-Roman auxiliary forces or joining specific military units that earned citizenship through service records. Cities implementing Latin law allowed provincial residents to elect officials who then received citizenship as well.
Roman women possessed a limited form of citizenship compared to their male counterparts which prevented them from voting or standing for civil office during most periods of Roman history. Most women remained under the guardianship of their father or closest male relative on the father's side until marriages ceased by Augustus' reign when women gained more independence.
The Porcian Laws from the early 2nd century BC protected citizens from torture and whipping. These laws ensured that torture and crucifixion were forbidden for citizens unless treason charges applied with trials occurring in Rome.