Siege weapons (Age of Empires II)

Siege Weapons in Age of Empires II become available in the Castle Age. They are powerful machines that excel at taking town enemy buildings or at battle against massed units. Unit upgrades for siege weapons as well as long-range siege weapons are only available in the Imperial Age.

They are built at the Siege Workshop or Castle. Cannon Galleons and Demolition Ships are sometimes considered naval siege units. They are built at the Dock. With the exception of Rams, all siege weapons possess a mid-to-long range.

Like ships, siege weapons cannot be healed by Monks, but have to be repaired by Villagers instead. Repairing siege weapons costs gold.

In order to train gunpowder siege weapons (Cannon Galleon and Bombard Cannon), Chemistry must first be researched.

Trebuchets, Onagers (since The Forgotten), and Siege Onagers can kill trees, making them the only units being able to do so, next to, of course, Villagers. That can be of high strategic importance, especially in maps with dense forests, e. g. Black Forest.

Categorization
Siege weapons are best divided into two categories: units that main purpose is to destroy buildings and units that excel at combat against enemy infantry and archers.

Anti-building
 * Rams
 * Bombard Cannons
 * Petards
 * Trebuchets

Anti-unit
 * Mangonels
 * Scorpions
 * Bombard Cannons
 * Organ Guns

As a unique unit, the Organ Gun is only available to the Portuguese. It is the only unique siege unit.

The Siege Tower cannot attack enemy structures or units and cannot be put in any of the categories above.

The Bombard Cannon can be put in both categories since it can outrange almost all buildings, but also can be effectively used against enemy units.

Although the two types of units can still fulfill each other’s roles, they are generally ineffective at doing so. For example, while Mangonels are devastating against groups of infantry and can outrange Town Centers, they deal little damage to Castles. Trebuchets, on the other hand, are excellent against fortifications but almost never hit any unit they target - excluding, to some extent, other Trebuchets.

Availability by Building
Note that the ships that listed here are not actually treated as siege weapons by the game, but as they match the description, they are included here.

Siege Workshop

 * Battering Ram -> Capped Ram -> Siege Ram
 * Mangonel -> Onager -> Siege Onager
 * Scorpion -> Heavy Scorpion
 * Siege Tower
 * Bombard Cannon

Castle

 * Petard
 * Organ Gun -> Elite Organ Gun (Portuguese only)
 * Trebuchet

Dock

 * Demolition Raft -> Demolition Ship -> Heavy Demolition Ship
 * Cannon Galleon -> Elite Cannon Galleon

Availability by Age
Note that the ships that listed here are not actually treated as siege weapons by the game, but as they match the description, they are included here.

Feudal Age

 * Demolition Raft

Castle Age

 * Battering Ram
 * Mangonel
 * Scorpion
 * Siege Tower
 * Petard
 * Organ Gun (Portuguese only)
 * Demolition Ship

Imperial Age

 * Capped Ram -> Siege Ram
 * Onager -> Siege Onager
 * Heavy Scorpion
 * Bombard Cannon
 * Trebuchet
 * Elite Organ Gun (Portuguese only)
 * Heavy Demolition Ship
 * Cannon Galleon -> Elite Cannon Galleon

Technologies
Listed below are all technologies that benefit siege weapons:

Note that technologies for ships that listed here, although ships are not actually treated as siege weapons by the game, but as they match the description, they are included here.

Note that Ballistics is available to all civilizations, but only affects certain siege weapons for the Spanish and Portuguese.

Civilizations
The Slavs, Celts, and Ethiopians have the best siege weapons due to their civilizations bonuses and unique technologies.

The Ethiopians are the only civilization to have access to all units from the Siege Workshop.

The Aztecs are the only civilization without access to any 'naval siege weapon'.

Civilization Bonuses
The following civilizations have bonuses that specifically benefit siege weapons:
 * Celts: Siege weapons fire 20% faster.
 * Chinese: Demolition Ships have +50% HP.
 * Huns: Trebuchets are 30% more accurate.
 * Slavs: Siege Workshop units are 15% cheaper.
 * Spanish: Cannon Galleons benefit from Ballistics.

Team Bonuses
The following civilizations have bonuses that specifically benefit siege weapons:
 * Celts: Siege Workshops work 20% faster.
 * Koreans: Mangonel.