The Romans adopted a tall rectangular shield that gave them advantages in battle when used properly. The size of the shield protected more of the body. The Romans fought in tight rectangular formations of approximately 100 men called maniples. The shields of the men in the maniple presented a continuous front, or shield wall, which protected them greatly from missile fire. They developed a formation variant called the Testudo (or turtle). In this formation, the shields covered all four sides and the heads of the men, allowing them to advance under missile fire. This was useful advancing toward a gap in an enemy wall, for example.
Benefit: +1 infantry armor against Ballista, Helepolis, and missile weapons. Only infantry and Academy units benefit from this technology.