Who gets it: Seleucid Empire, Seleucid Rebels (Asia Minor), Seleucid Rebels (Upper Satrapies) and Lysiad Kingdom

Greetings, mighty Basileios, may you live long and prosper, Agathe Tyche. Our Macedonian soldiers are the best in the world, sons of the divine Herakles themselves, worthy of Alexander the demigod. Yet, sometimes us mortals have to change, and it seems that now a new type of armour has become available, which will protect the Thorax (chest) of our soldiers. Allow us to retrain our men to fight as Thorakitai and you will see how effective our Greek armour is. Long live the dynasty of Seleukos!

It fires when mercenaries have been hired by Seleucid Empire at least 15 times (each hiring counts once, however many units it takes on).

The game checks this at the end of every round.

5 units can be recruited once it fires:

Unit	Who can raise it
Neocretan Archers	Free Peoples
Seleucid Chrysaspides	Free Peoples
Seleucid General's Bodyguard (Late)	Free Peoples
Seleucid Thorakitai	Free Peoples
Thureophoroi Cavalry	Free Peoples