Civilizations (Age of Empires II)

Aztecs
The Aztecs appear in The Conquerors Expansion and their unique unit is the Jaguar Warrior which is strong against other infantry units. The Aztecs are unable to field cavalry, so instead of scout cavalry at the start of the game, they receive an eagle warrior, which can be trained at the barracks. The strongest feature is arguably the monks, which, as monastery technologies are researched,can reach almost 100 hit points. They can, for example, take a direct hit from a cannon galleon and survive to convert it.

Britons
The Britons (in the campaign the concentration is on the English). Their unique unit is the Longbowman, which is an extra long-ranged archer. They have many bonuses which improve archers along with strong economic bonuses. Their archery ranges work 20% faster also.

Byzantines
The Byzantines, sister to the Roman empire. Its major strength is its defense in their buildings and units. Its towers and other buildings have more hit points (hp) and are stronger in attack. Their unique unit, the Cataphract, is an armored cavalry unit that's good at defense and good against infantry. All counter-units(camel, skirmisher, and spearman) are cheaper.

Celts
The Celts (in the campaign the concentration is on the Scottish). Its major strength is its infantry units, siege weapons, and speed. The have extra bonus in their buildings and units. The Celtic infantries are 15% faster than their counterpart units in other civilizations. Even more importantly, their siege weapons fire 20% faster. This important attribute means you can destroy other civilizations' buildings 20% faster. Their Woad Raider is the fastest infantry unit. They are unarmored but are excellent raiders.

Chinese
With the Japanese, Korean, and Mongols, the Chinese are one of the civilizations belonging to the East Asian culture. Their major advantage is the cost of development and technology. They start off the games with 6 villagers instead of 3 villagers. It is a more important attribute than it may sound, because it greatly enhances your speed to collect resources, create buildings, and to advance to the Feudal Age. They also incur cheaper cost in researching any technologies. In Feudal Age the cost of research is cheaper by 10%, 15% in Castle Age, and 20% in Imperial Age. Their unique unit is the Cho Ku No, an archer unit with a rapid-firing crossbow. They have a very strong attack, for they fire multiple arrows at a time, but shorter range.

Franks
With the Celts and Britons, the Franks are one of the civilizations belonging to the Western European culture, but are still a Germanic tribe. The Franks are able to build castles at a 25% discount. It allows them to build the strong unique units and siege weapons, and advance to Imperial Age, faster than other civilizations. All of their cavalry units have 20% more hitpoints; this is their best advantage when the game proceeds to the later ages. Their unique unit is the Throwing Axeman, which is an infantry unit with ranged attack. They throw axes that do hand damage at range and are effective against buildings.

Goths
The Goths are Germanic barbarians from east of the Danube. With the Vikings and Teutons, the Goths are one of the civilizations belonging to the Eastern and Northern European culture. The Goths are able to build infantry at a cheaper cost. Their unique unit, the Huskarl, is an infantry unit with excellent Pierce Armour that gives them good resistance to archer and missile attacks. They are very cheap as they cost negligible amount of gold (30 gold/unit), and they are nearly immune to archer units. A good strategy for them is to rush as fast as possible because they get numbers virtually instantaneously.

Huns
The Huns appear in The Conquerors Expansion and their unique unit is the Tarkan which is a cavalry unit, effective against buildings. As being nomadic tribes, they don't need any houses which allows a lot of rush tactics in multiplayer games. Their stables (in team games) produce cavalry 20% faster, along with their Trebuchets' aim being much more exact than the other civilizations.

Japanese
The Japanese are a far-eastern empire and their unique unit is the Samurai, a fast-attacking infantry unit which is effective against unique units of other nations. Their bonuses include infantry attack speed and major economic bonuses on land and sea.

Koreans
The Koreans appear in The Conquerors Expansion and their unique units are the War Wagon (heavily armored archery unit) and the Turtle Ship (heavily armored ship which is good against Fire Ships and Demolition Ships. Their towers have the most range in the game, which makes the Koreans excellent at blocking strategic choke points and narrow areas. Their onagers also have +1 range.

Mayans
The Mayans appear in The Conquerors Expansion and their unique unit is the Plumed Archer, which are stronger, faster and have better pierce armor but less attack. Their major bonus is that Archery Range units cost -10% Feudal Age, -20% Castle Age, and -30% in the Imperial Age. Their walls are cheaper along with all resources lasting 20% longer.

Mongols
The Mongols are barbarians from Mongolia in the east. Their major advantage is their strong and fast Cavalry Archers and the siege weapons. They collect food 15% faster by hunting than other civilizations. The Mangudai, their unique unit, is a cavalry archer which runs and shoots quickly, and is good against siege weapons. They are are superior at raiding the towns of enemies and engaging in hit-and-run battles with slower units.

Persians
The Persians are a middle east empire spanning from Turkey to India and Egypt. With the Turks, Saracens and Byzantines, the Persians are one of the civilizations belonging to the Middle Eastern culture. Their major advantage is their strong economy and their strong cavalry. They start the game with 50 more food and wood than other civilizations, the town centers and docks work faster, and their knights have +2 attack bonus versus archers. Their unique unit, the War Elephant, is very heavily armored and difficult to destroy as well as having a strong attack but being very expensive. They are also very slow and vulnerable to conversion of monks.

Saracens
The Saracens are the Arabs of the Middle East. The Saracens are one of the civilizations belonging to the Middle Eastern culture. Their major advantage is their stronger Cavalry Archers and the naval units. Their foot archers have +1 attack bonus versus enemy buildings, and cavalry archers have a +3 bonus. Their war galleys have 2 times attack speed. Therefore, they are a very strong army in destroying buildings using long-range units. The Mameluke, their unique unit, is a camel unit (classed as cavalry) with ranged attack (however, the range is a meager 3). They have a bonus vs cavalry units and their damage is normal damage as opposed to pierce damage. Be reminded, however, that they are very expensive. Saracens have a very powerful civilization and troops because they have most of the technologies available to them.

Spanish
The Spanish appear in The Conqueror's Expansion and their Conquistadors (mounted Hand Cannoneers) and Missionaries (mounted Monk) are their unique units. Spanish cannon galleons have the advantage of being allowed to benefit from the technology, ballistics (which makes ranged units fire faster and more accurately). The Spanish are one of the most flexible nations available in AOE II. They have all the blacksmith upgrades (which does not cost them gold). Paladins (the strongest of the cavalry) are available to them. Champions are also available. In the archer department, though they lack the crossbowman and the arbalest, they do have their unique unit, the conquistador. Siege-wise, they are average. They lack siege onagers and heavy scorpions so anti-personnel siege is not recommended as an investment for a Spanish player. They do, however, have the siege ram which is very effective in demolishing cities. On the high seas, they possess all the naval technologies including the fast fire ship and the galleon. Thus, the Spanish are among the top of the naval arena. The Spanish weakness lies in their beginning ages. Aside from builders building 33% faster, they possess no bonuses for gathering. It is not until the Castle age that the Spanish start to catch up and eventually overtake others.

Teutons
The Teutons are a Germanic tribe and are one of the civilizations belonging to the Eastern and Northern European culture. Their major advantage is their economy, defensive technologies, and their extremely strong unique unit. Their towers and town centres have an attack bonus, their monks heal units faster, and their farms cost 33% less. Their unique unit is the Teutonic Knight, a heavily armored infantry unit which is difficult to destroy. They are arguably the strongest infantry units in the game. They have double as much hp and attack than most other units, and cost almost twice as much too. They are extremely slow but they are almost invulnerable to most attacks.

Turks
With the Saracens, Persians and Byzantines, the Turks are one of the civilizations belonging to the Middle Eastern culture. Their major advantage is their cheap and strong gunpowder units. They have discount in researching Chemistry and other gunpowder technologies. Their gun powder units have 50% more hp. As gunpowder units cost a lot of gold, to compensate their gold miners are 15% faster. Their unique unit is the Janissary, which is a more powerful version of the Hand Cannoneer with no minimum and extra range as well as a more powerful close attack. They are the only gunpowder units that are available at the Castle Age. Due to their strong gunpowder force, they could easily rise to dominance in later stage of the games.

Vikings
The Vikings from northern Europe are a raiding force. With the Teutons and Goths, the Vikings are one of the civilizations belonging to the Eastern and Northern European culture. Their major advantage is their stronger infantry and great naval technologies. All of their warships have 20% training discount. All of their infantry units enjoy 10% more HP at Feudal Age, 15% in Castle Age, 20% in Imperial Age. They are the only civilization which have two unique units (except that in the expansion set the Koreans and the Spanish also have two unique units). Their unique units are the Longboat, a very powerful warship good against Fire Ships and Bombard Cannons, and the Berserks, very powerful infantry units who can heal themselves gradually. With such powerful infantry, their cavalry options are limited.