Castle (Age of Empires II)

"Used to create your unique unit, build Trebuchets, and improve villagers and buildings."

- Age of Empires II description

The Castle is a defensive structure and military building in Age of Empires II that becomes available once the Castle Age is reached. It is an important building in later stages of the game, being a powerful fortification and providing unique technologies and units.

Castles also support 20 population and cannot be converted.

When playing Regicide games, each player starts with an additional Castle near to their Town Center.

Tactics and placement
Castles are often built inside minor fortifications outside the player's settlement. Surrounding the entire base with Walls along with Towers provides additional protection. If a river separates their base from the enemy's, walling up the river's shallows and building a Castle at the shoreline helps to protect from Transport Ships or ambushes. Castles are also of great use at major choke points, especially if Murder Holes is researched. Garrison a few melee units to fend off Battering Ram attacks is helpful.

Alternatively, players may build Castles inside their bases, which protects the economy against enemy raiding effectively, while making the Castles less vulnerable against long ranged siege units like Trebuchets.

For Teuton players, researching Crenellations adds +3 range to Castles. This allows them to match the range of Bombard Cannons and (non-Elite) Cannon Galleons, making their Castles more well-rounded, especially on naval maps. Still, long-ranged siege units remain a heavy threat, also because Castles always fire at the closest unit and not the most dangerous or expensive. Consequently, a Castle under attack needs constant attention of the player in order to fulfill its roles effectively.

If running for a Relic or Wonder victory, Castles can become very useful to build up the defense of the Wonder or the Monasteries holding Relics, but the support of other structures such as Walls and Towers is also required. Also, the player must have sufficient numbers of troops (especially cavalry) for countering enemy siege units. In Regicide games, the Castle is a safe place for the King if properly supported by other defensive structures.

Attack and range damage
An empty Castle is able to fire five arrows at a time, with a base damage of 11 each. Garrisoning either Villagers or archers adds additional arrows to the Castle's fire, up to maximum of 21. One base arrow and 20 additional arrows are fired. The Castle inherently already has 4 "power" which is listed in the attack with parenthesis. Not all garrisoned units add the same number of arrows, their value is generally dependent on two factors: attack and Rate of Fire. The more damage output the garrisoned units have the higher the number of arrows fired.

For a Teuton player with Crenellations researched, fully garrisoning infantry of the same type enables the Castle to fire 12 arrows (7 extra).

The following table shows the maximum number of arrows a Castle can fire, when it is garrisoned with units of the same type:

Trainable units and technologies
Clicking on the icon links to the corresponding page.

Blue: Units

Green: Technologies

Purple: Unique units

Civilization bonuses

 * Aztecs: Castle units are created 15% faster.
 * Burmese: Researching Herbal Medicine is 50% cheaper.
 * Byzantines: Castles have +10%/+20%/+30%/+40% HP in the Dark/Feudal/Castle/Imperial Age. Town Watch is free.
 * Chinese: Technologies that benefit Castles are 10%/15%/20% cheaper in the Feudal/Castle/Imperial Age. Castles technologies are 15%/20% cheaper in the Castle/Imperial Age.
 * Franks: Castles are 25% cheaper.
 * Incas: Castles are 15% cheaper.
 * Koreans: Castles are built.
 * Persians: Researching Town Watch and Town Patrol is 10%/15%/20% faster in the Feudal/Castle/Imperial Age.
 * Spanish: Castles are built 30% faster.
 * Teutons: Murder Holes are free.
 * Vietnamese: Conscription is free.

Team bonuses

 * A team containing Berbers: With Kasbah researched, Castles work 25% faster.
 * A team containing Malians: University technologies that benefit Castles are researched 80% faster.

The Age of Kings

 * Castles have 10 Line of Sight.

The Conquerors

 * Herbal Medicine introduced.
 * Teutons: Crenellations introduced.

The Forgotten

 * Castles now have 11 Line of Sight.
 * Chemistry now affects Castles.
 * Celts: Stronghold introduced.
 * Koreans: Castles are now built 33% faster.
 * Persians: Boiling Oil introduced.

Architecture
Each architectural group of civilizations has its own unique designs for its Castle.
 * The Western European Castle resembles the front gate of Bodiam Castle in England.


 * The Central European Castle has a blocky design with four tall towers and two shorter ones with a bridge in between, bearing a distinct (and ironic) resemblance to Rochester Castle in England.
 * The East European Castle resembles the Malbork Castle in Poland.
 * The Mediterranean Castle appears to be based on the Castello di Torrechiara in Parma, Italy.
 * The East Asian Castle bears an uncanny resemblance to the main keep of Japan's Osaka Castle.
 * The Native American Castle, while not based on anything specific, appears to resemble one of the temples of Palenque.
 * The Middle Eastern Castle most resembles Krak des Chevaliers in Syria.
 * The Indian Castle is a possible reference to the Red Fort, even though it isn't red. There are, however, some architectural similarities.
 * The African Castle appears to be made up and is only based on architectural features of mud buildings, as most, if not all, documented African castles are made of stone.
 * The Southeast Asian Castle, like the Native American one, seems to be based on a generic Southeast Asian temple.

Trivia

 * The Castle is the most expensive building in the military sector.
 * The Castle of East Asian civilizations appears to have more wood than stone, however its price remains the same and it still only requires stone.
 * The Native American Castle looks like a temple because the Aztecs, Incas, and Mayans never actually built any Castles, but the tall temples were apparently good places to defend from invaders like the Spanish.

History
"The first castles appeared in Europe in the ninth century as an improvement of the local lord’s stronghold. Castles were tactically defensive but strategically offensive. Because they were so difficult to capture if adequately defended, they provided a secure base from which a mobile force of warriors could extend political control. A local lord installed himself inside with a professional force of fighting men to serve him. Castles spread across Europe in the tenth and eleventh centuries in response to weak central authority and barbarian raids from the north and east. Kings spent the rest of the Middle Ages trying to take back control of castles raised by local lords. The development of dependable mobile heavy artillery in the fifteenth century finally made castles obsolete."

- Age of Empires II manual