Lex Scantinia penalized a sex crime (stuprum ) against a freeborn male minor (ingenuus or prasetextatus). It may also have been used to prosecute adult male citizens who willingly took a passive role in sexual intercourse with other men. The law did not prohibit homosexual activity (as long as the passive partner was not a citizen in good standing), but was aimed at protecting a [male] citizen's body from sexual abuse (stuprum). Lex Scantinia seems to have been principally used for harassing political opponents whose private behaviour left them vulnerable to criticism as passive homosexuals.
It is not clear if the law made stuprum against a minor a capital crime: it is possible that a large fine may have been imposed instead, since law courts of the Republic rarely executed Roman citizens. Conflation of the Lex Scantinia with later or other legislation on sexual behavior has led to erroneous assertions that the Romans had strict laws and penalties against homosexuality in general.
Quintilian refers to a fine of 10,000 sesterces for committing stuprum with a freeborn male, which is sometimes construed as referring to the Lex Scantinia, even though the law is not named in the passage.
There is no Latin word for “homosexual” or “heterosexual.” Within Roman sexuality, the principal dichotomy was active/dominant/masculine and passive/submissive/"feminine." An adult male citizen was defined by his libertas, "liberty." Allowing his body to be used for pleasure by others was considered servile or submissive and a threat to his integrity. Having sex with other males of lower status, such as prostitutes or slaves, did not compromise a Roman’s masculinity as long as he took the active, dominant role.
The Lex Scantinia penalized the debauchery (stuprum) of a youth, but may also have permitted the prosecution of citizens who chose to take the pathic ("passive" or "submissive") role in homosexual relations. Suetonius refers to the law in the context of punishments for those who are "unchaste," which for male citizens often suggests pathic behavior. Ausonius made an epigram in which a semivir, "half-man," fears the Lex Scantinia.
It has been argued that the Lex Scantinia was concerned with the rape of freeborn youth, but the narrowness of this interpretation has called into question. The law may have codified traditional sanctions against stuprum involving men, as a forerunner to the Lex Julia de adulteriis coercendis, which criminalized adultery with women. The early Christian poet Prudentius makes a scathing joke that if Jupiter had been subject to Roman law, he could have been convicted under both the Julian and the Scantinian laws.
Freeborn Roman boys wore a protective amulet (bulla), which was a visible sign that they were sexually off limits. Puberty was considered a dangerous transitional stage in the formation of masculine identity. When a boy came of age, he removed his bulla, dedicated it to his household gods, and became sexually active under the patronage of Liber, the god of both political and sexual liberty. Pederasty among the Romans involved an adult male citizen and a youth who was typically a slave between the ages of 12 and 20.
The law protected only youths from freeborn families in good standing. Youths born or sold into slavery, or those who fell into slavery through military conquest, were subject to prostitution or sexual use by their masters. Male prostitutes and entertainers, even if "free," were considered infames, of no social standing, and were thus excluded from the protections afforded the citizen's body. It is possible that male slaves were granted freedom in recognition of a favored sexual relationship with their master, however in some cases of genuine affection it is possible that those slaves may have remained legally slaves, since under the Lex Scantinia the couple could have been prosecuted if both were free citizens.
The infrequency with which literary sources invoked the Lex Scantinia suggests that prosecutions during the Republic were aimed at harassing political opponents, while prosecutions during the reign of Domitian occurred in a general climate of political and moral crisis.