Triplex Acies, testudo and wedge were the main strategic formations that the Roman army used in wars

The "Triplex Acies" (triple combat order), testudo (tortoise), and wedge were some of the strategic formations the Roman army utilized to confront their enemy.

The troops were positioned in three ranks for the triple combat order: the Hastati, who were the least experienced, were in the front line; the Principes, who was in the second rank; and the Triarii, who was the most experienced, was in the third and final rank. To provide even more freedom for movement, the three lines had alternating gaps. When facing defeat, the first two lines retreated onto the Triarii to reorganize the line and enable a counterattack or a safe retreat.

In the testudo formation, the soldiers would line up their shields to create a dense formation that was shielded from the front and top. The testudo offered steady defensive strength against hostile troops while providing protection from arrows and other missile weapons.

An aggressive military formation was called the wedge. It was employed to cut through enemy lines since it was shaped like a triangle.