Onager (Age of Empires II)

"Stronger than Mangonel. Wheeled siege weapon used to attack a small mass of units."

- Age of Empires II description

The Onager is a ranged siege unit in Age of Empires II that can be trained at the Siege Workshop once the Imperial Age is reached. It is primarily used against large groups of enemies. Its high attack and splash damage make it a powerful unit, especially against archers and slow-moving units. Its main offsets are its projectile speed, minimum range, and tendency to harm friendly units caught in its blast. Onagers can attack ground and.

Onagers are available to all civilizations except for the Huns and Turks.

Tactics
Onagers are devastating against archers and slow-moving units, but cannot defend themselves against most melee units. Therefore, they need to be guarded in most situations. Archers are often used, because own melee units are usually endangered by the own Onagers. But archers don't cover the Onager's main weakness adequately, which is cavalry. Therefore, Onagers are also often paired with Halberdiers. That combination is especially prominent with the Celts and Slavs.

Onagers are very effective against naval units. The AI will often send out Onagers as a shore defense to protect its buildings.

Since The Forgotten, Onagers are able to cut down trees, making them valuable in maps with large areas of forests like Black Forest by enabling to the player to attack from behind a forest.

Civilization Bonuses

 * Aztecs: Onagers are created 15% faster.
 * Burmese: Researching Faith is 50% cheaper.
 * Celts: Onagers fire 20% faster. Onagers can convert herdables even if enemy units are next to them.
 * Chinese: Technologies that benefit Onagers are 20% cheaper.
 * Portuguese: Onagers cost 15% less gold.
 * Slavs: Onagers are 15% cheaper.

Team Bonuses

 * A team containing Celts: Onagers are created and upgraded 20% faster.
 * A team containing Koreans: Onagers.
 * A team containing Malians: Researching Chemistry and Siege Engineers is 80% faster.
 * A team containing Teutons: Onagers are more resistant to conversion.

The Age of Kings

 * Onagers move at a speed of 0.5.

The Conquerors

 * Onagers now move at a speed of 0.6.
 * Onagers gain +12 bonus damage against siege weapons.
 * Heresy introduced.
 * Celts: Furor Celtica introduced. It gives Onagers +50% HP.
 * Mongols: Drill introduced.
 * Koreans: Shinkichon initially gives Onagers +2 range. With patch 1.0c, the effect was reduced to +1.
 * A team containing Koreans: Onagers have +1 range.

The Forgotten

 * Onagers can cut down trees.
 * Celts: Furor Celtica now gives +40% HP to Onagers.
 * Teutons: Ironclad introduced.
 * A team containing Koreans: Onagers minimum range reduced (instead of +1 range).

Trivia

 * In reality, the Onager was invented long before the Mangonel by the Ancient Romans. The Onager is credited as being the first Torsion Spring or "Petraria Arcatinus"-type catapult, as all catapults before that are called Ballista and/or Scorpions.

History
The onager was an improvement of the mangonel; it was larger, more powerful, and hurled a heavier payload for greater distance.