I know that the answer to the question "Why were other members of Decius Muls' family also committed to his offering" is in "The devotio was the most extreme offering a Roman general could make, promising to offer his own life in battle along with the enemy as an offering to the underworld gods. Livy offers a detailed account of the devotio carried out by Decius Mus; family tradition maintained that his son and grandson, all bearing the same name, also devoted themselves. Before the battle, Decius is granted a prescient dream that reveals his fate. When he offers sacrifice, the victim's liver appears "damaged where it refers to his own fortunes". Otherwise, the haruspex tells him, the sacrifice is entirely acceptable to the gods. In a prayer recorded by Livy, Decius commits himself and the enemy to the dii Manes and Tellus, charges alone and headlong into the enemy ranks, and is killed; his action cleanses the sacrificial offering. Had he failed to die, his sacrificial offering would have been tainted and therefore void, with possibly disastrous consequences. The act of devotio is a link between military ethics and those of the Roman gladiator.". Can you tell me what it is?
A:
family tradition