What purpose does a breastplate serve? The breastplate Roman soldiers wore during battle was explicitly designed to protect the upper body's most vital parts. This included the chest area, safeguarding the heart and lungs; the stomach; and the rest of the abdominal region, which houses other critical organs such as the liver, spleen, and intestines. The sturdy construction of the breastplate was essential for preventing fatal injuries to these essential bodily components from weapons like swords, arrows, and spears. Without a breastplate, a soldier would be asking for death, as any attack could instantly become fatal. With a sturdy breastplate, the same attacks become ineffective and useless as blows glance off the armor.