The Hellenistic Kataphraktoi are armored in an expensive combination of lamellar armor and chain. They are to be used as heavy shock cavalry, but have staying power in melee because of the sheer weight of their armor.
After suffering heavy losses to the Parthoi and Armenioi Kataphraktoi, the Seleukid and Baktrian empires produced their own versions of these heavy horsemen, both adapting the tactics and style of warfare to Hellenic technology and using superior metalwork to make them even more heavily armored. They are armored in an expensive combination of lamellar armor and chain, with heavy felt sandwiched in the middle. The resulting armor is tough and flexible, but offers outstanding protection. They are to be used as heavy shock cavalry, and have staying power in melee because of the sheer weight of their armor. They are slightly heavier than their Parthoi counterparts, but lack the deadly maces that the Parthoi carry and also the élan of their elite Parthoi counterparts. Their horses are more heavily armored than those of the Hetairoi, but they lack the characteristic fierceness and discipline of the elite Diadochoi cavalry.
Historically, Hellenistic Kataphraktoi were at least as good as their Parthoi enemy, but most Seleukeis commanders did not quite understand how to use this cavalry. They won great victories over the Parthoi when supporting the tougher and more elite Hetairoi, compelling the Parthoi to settle for a peace treaty and suzerainty over some of the Seleukid eastern possessions. They passed into history when most of the unit was bribed by Pompeius during his conquest of the east. They formed the basis for the Romaioi Kataphraktoi of later ages.