Sacramentum

A Sacramentum is a solemn oath or vow that renders the swearer "given to the gods" should they violate it. It is referred to as the most sacred of bonds, and cannot be undone. A Sacramentum is believed to establish a direct relation between the person swearing the pledge and the gods themselves.

It is common practice in the Eternian Empire to require a new citizen to make a Sacramentum promising loyalty to the Empire before they can be recognized as a citizen. Likewise, deserters or other traitors to the Empire who manage to spare themselves from death are typically required to make a Sacramentum, regardless of the rest of their sentence.