Scorpion
From Age of Empires Series Wiki
The Scorpion is a Siege Unit that is featured in Age of Empires II. The Scorpion fires large arrow-like bolts. It is effective against groups of enemy units as it can cause damage to multiple units. Sc is built built at the Siege Workshop during the Castle Age. Scorpions upgrade to Heavy Scorpion. Unlike Mangonels, scorpions do not damage friendly units. This can make all the difference in a pitched close quarters battle.
[edit] Tactics
Scorpions are good against slower units such as Infantry, Archers and Monks, where its slower-moving bolts may have maximum efficiency. Scorpions are bad against Woad Raiders and Stable Units, which can dodge its missiles and close the gap quickly should they chose to engage.. Scorpions, like most Siege Units, should be well protected, as the Scorpions slow speed makes them very vulnerable to attack. If the opponent has primarily Cavalry, then it is a good idea to retreat Siege Units and send in Spearmen. Position the scorpions behind them so they don't get hit.
When used correctly, scorpions can be quite devastating. A medium-sized group of scorpions can decimate whole armies of infantry and archers in the blink of an eye, and even hold out well against cavalry in sufficient numbers. However, scorpions are always vulnerable to longer ranged attacks such as that from Bombard Cannons. When properly manouvered, cavalry archers and especially mangudai can deal with scorpions efficiently.
The Chinese technology Rocketry increases scorpion damage by a massive 33 percent which allows them to destroy even cavalry with relative ease.

