The Vietnamese are a team-focused archery civilization with many bonuses that favor the late game. Their unique units, the Imperial Skirmisher and the Rattan Archer, provide tremendous anti-archer capability and make the Vietnamese a fearsome opponent to other archery-specialized civilizations.
The Vietnamese can field resilient archers, thanks to their bonuses and unique units. They can train every unit at the Archery Range except the Hand Cannoneer, and can research every important unit upgrade except for Parthian Tactics. Their Imperial Skirmisher upgrade is a unique unit upgrade for the Elite Skirmisher, and their Rattan Archer is an archer with high pierce armor and reasonably high attack; both of these units excel against other archers. All Vietnamese archers have more hit points than traditional archers, giving them greater durability against Onagers and even allows them to trade favorably against ChineseChu Ko Nu.
The Vietnamese shine in multiplayer, as their civilization bonus reveals the location of each enemy Town Center. This saves the Vietnamese player valuable scouting time and allows them and their teammates to adjust their strategy according to enemy position. Their Paper Money unique tech grants each player on the Vietnamese team 500 gold upon completing research, giving the team a much-needed gold boost in the late game.
Finally, the Vietnamese get free Conscription, saving them resources and giving them a critical early Imperial Age boost to unit production. They also have access to every important unit upgrade for their infantry and cavalry lines, only lacking Hussars and Paladins. Their Battle Elephants are also more durable thanks to the Chatras unique tech, combined with their access to Bloodlines.
As mentioned before, the Vietnamese are a team-oriented civilization. They are weaker in one-on-one games due to the fact that they do not have any significant early-game economic bonuses and most of their bonuses come into play in the late game. The Vietnamese are also particularly vulnerable to Dark Age and Feudal Age rush strategies, especially from stronger early game civilizations such as the Vikings, Huns, Mongols, Aztecs, Mayans, and Malay.
At the start of the game, the first priority of the Vietnamese is to play defensively and scout for early-game rushes. Since the enemy Town Centers are revealed at the start of the game (or revealed after being built, like in Nomad-style games), the Vietnamese player can determine their strategy based on positioning and then take appropriate action. If the enemy is much closer than expected, or is an aggressive, early-game civilization, the Vietnamese player should prioritize gathering Stone and placing defensive structures.
At the Feudal Age, the Vietnamese have two options: continue playing defensively, or go on the offensive and raid with Archers and Skirmishers. Producing Spearmen is also a good idea as they can defend the base, protect Archers, and/or stop Scout rushes.
During the Castle Age, the player should continue to focus on building Crossbowmen and Elite Skirmishers as Archery Range units' defensive capabilities increase with each age. Players should also strongly consider building a Castle for access to the Rattan Archer, free Conscription upon reaching Imperial, and access to the Chatras tech for bulky Battle Elephants. Even without Parthian Tactics and Husbandry, a Cavalry Archer rush can be viable due to access to Bloodlines combined with the hit point bonus (and access to the Heavy Cavalry Archer upgrade in the Imperial Age).
The Vietnamese shine in the Imperial Age; durable Heavy Cavalry Archers, Arbalests, Imperial Skirmishers, and Elite Rattan Archers will be the main backbone of any Vietnamese army, with Halberdiers and Battle Elephants as main front-line protection and Trebuchets and Bombard Cannons as the main siege support. When gold becomes scarce in the late Imperial Age, the Imperial Skirmisher gives the Vietnamese player an edge in "trash wars," despite their lack of Hussars and Blast Furnace. Paper Money can also generate a decent amount of gold to the Vietnamese team in multiplayer, and is always worth consideration.
The Vietnamese are perfectly suited as a "support" civilization due to the identification of enemy Town Centers, Paper Money unique tech, and team bonus (Imperial Skirmisher upgrade available at allied archery ranges).
Civilizations with already powerful trash units (such as the Berbers, the Magyars or the Malay) or those with archer/skirmisher specific bonuses (such as the Aztecs' Atlatl upgrade and Incas' Andean Sling) may abuse this advantage greatly and acquire an alarmingly good trash army.
The Berbers are a strong ally to the Vietnamese, as the Vietnamese receive the Genitour unit at the Archery Range, which benefit from the Vietnamese hit point bonus. Vietnamese Castles can produce Rattan Archers faster thanks to Kasbah. The Berbers' strong early game can help to offset the Vietnamese weak early game, and access to the Imperial Skirmisher upgrade is a nice addition to the Berbers' already strong anti-cavalry archer capacity with Camel Archers and Genitours.
A Byzantine-Vietnamese alliance is particularly beneficial, as the Byzantines have cheaper trash units and can access cheaper Imperial Skirmishers. The gold from Paper Money facilitates the acquisition of Cataphracts, which can help to counter civilizations with high pierce armor infantry like the Goths. In the Feudal Age, cheap Byzantine spear units can cover the weak Vietnamese early game and help fend off early cavalry rushes.
The Teutons can utilize Imperial Skirmishers to counter gunpowder and cavalry archer civilizations like the Spanish and Mongols, respectively, and the Vietnamese player's archer army can target civilizations with strong anti-infantry units (e.g., Japanese, Aztecs). The Teutons, in turn, offer great siege, fortifications, and an anti-conversion team bonus that shields Vietnamese Battle Elephants from Monks. Finally, Paper Money helps soften the economic blow of training gold-intensive units like Paladins, Monks or Teutonic Knights.
The Britons' team bonus that allied Archery Ranges work 20% faster allows both players to flood the map with Imperial Skirmishers in trash wars. In the Vietnamese player's case, they can quickly mass-produce high hit point archers in all stages of the game.
The Saracens' bonus damage against buildings will make the Rattan Archer far more threatening to enemy towers thanks to the unit's natural high pierce armor.
The Italians are also a nice ally for the Vietnamese, since both the Vietnamese and Italians can get each other's team-bonus-based unique units.
Civilizations with strong early games can abuse the Vietnamese enemy Town Center location bonus to quickly, accurately rush enemy positions. In the Feudal Age, after Cartography is researched, the LOS around enemy Town Centers is shared between allies. The Portuguese are a valuable ally in this regard, as they provide free Cartography at the start of game to their team.
Despite the Vietnamese bonuses and access to the Paper Money tech, it is important to note their exceptionally poor synergy with the Turks. The Turks do not have access to Elite Skirmishers, and therefore cannot get the Imperial Skirmisher upgrade. The faster gunpowder unit creation team bonus from the Turks matters little to the Vietnamese as they do not get Hand Cannoneer, but may help to produce Bombard Cannons and Cannon Galleons.
In conclusion, Vietnamese may struggle in one-on-one situations but their excellent direct and indirect support should never be underestimated in team games.
The Rattan Archer is a well-rounded archer with high pierce armor and counters almost all types of archers, even those from prominent archer civilizations like the Britons, Mayans, Italians, Mongols, Chinese, and Magyars. They can resist Scorpion bolts, so civilizations that utilize them like the Khmer, Chinese, or Ethiopians should take extra precautions and mix in other siege units like Onagers or Rams.
Civilizations with poor early and/or mid-game (like the Turks, Portuguese, and Khmer) may have trouble against an early Vietnamese archer rush, thanks to the Vietnamese HP bonus and enemy location bonus. This is especially true in open maps like Arabia, if starting in the Dark Age.
The Vietnamese have a small advantage in closed maps like Black Forest against civilizations with poor late-game strategies (like the Aztecs, Huns, and Malians), thanks to their archers and offensive towers (which only lack Masonry and Architecture).
Vietnamese Battle Elephants buffed with the Chatras tech are strong in melee fights and arrow-resistant, and therefore archer-reliant civilizations like the Mayans and Britons will find difficulty in taking them down. Civilizations like the Aztecs, Franks, Goths, and Malays should also take precautions against these Battle Elephants due to their ability to counter non-pike, non-camel melee units. Massed, non-pike infantry such as the Karambit Warriors, Shotel Warriors, Goth Huskarls, and Champions are all susceptible. Finally, Vietnamese Battle Elephants can become a viable replacement for siege units, so civilizations with poor defenses (like the Huns, Goths, and Magyars) may struggle against them.
Access to Bombard Cannons gives the Vietnamese an advantage against defensive civilizations like the Byzantines and Incas.
The Vietnamese have access almost all Dock units and techs (besides Shipwright and Fast Fire Ship; see in Disadvantages), so they are also able to perform a Galley rush against civilizations with poor early navy.
The Vietnamese Skirmisher line is bulkier than most civilizations and can be improved to Imperial status, giving them an advantage against other prominent archer civilizations like the Mayans, Chinese, Britons, and Ethiopians. They are a strong trash unit, and perform well against civilizations with poor trash units (such as the Turks) or poor Militia-line infantry (such as the Persians).
Despite their pierce armor and bulk, Rattan Archers have low melee armor. Prominent infantry and cavalry civilizations (like the Aztecs, Huns, Franks, Goths and Malay) can usually capitalize on this, or counter with fast infantry like Celt Woad Riders, Ethiopian Shotel Warriors, or Eagle Warriors. Siege-focused civilizations like the Ethiopians, Koreans and Celts can use Onagers to counter contingents of Vietnamese archers, since Onagers deal melee damage. Massed Japanese Samurais can also pose a threat to the Rattan Archer due to their bonus damage against other unique units.
The Vietnamese do not have early economic bonuses and are weak in the early game, despite the fact that they can perform archer rushes in the Feudal Age. Civilizations with good early aggression (like the Aztecs and Huns) can rush or counter-rush them, especially in open maps starting from the Dark Age, or in one-on-one games.
The Malians, Goths, and Celts can counter the Vietnamese with high pierce armor and/or speed. The Malian infantry pierce armor bonus partially negates the overall effectiveness of the Vietnamese archers, and their Gbetos can move extremely fast to pick off archers with their high ranged attack. Similarly, the Goths can simply field a swarm of Huskarls, which have high pierce armor and an attack bonus vs archers and buildings. Celtic infantry can also be unpleasant for the Vietnamese to deal with, as they can move fast enough to avoid arrow-fire (especially the Woad Raider).
The Mayans, Incas and Aztecs have access to Eagle Warriors, which utilize their high pierce armor and attack bonus vs cavalry and siege units to counter Archers, Battle Elephants, and Bombard Cannons; these three units are the core of the Vietnamese army. It is also worth mentioning that all three civilizations have good anti-cavalry units in the form of the Incan Kamayuks, Aztec Pikemen (buffed with Garland Wars), and fully-upgraded Mayan Halberdiers.
Vietnamese Battle Elephants can be countered by the Viking infantry after researching the Chieftains tech, Italian Genoese Crossbowmen, and by civilizations with prominent Halberdiers (like the Japanese, Byzantines, Slavs and Celts) or decent Camels (like the Berbers, Indians, and Saracens). They are also vulnerable to conversion, so civilizations with good monks (like Aztecs, Portuguese, Spanish, and Slavs) can convert them easily.
Berber Genitours can counter the Vietnamese archers and are arguably on par with Vietnamese Imperial Skirmishers. The Berbers also have cheap Hussars and Camels that can counter Battle Elephants and Bombard Cannons.
Civilizations with any high hit point, high pierce armor units (like the Korean War Wagon or elephant units) can be a threat to Vietnamese archers if the player forgets to make the archers focus-fire. These units, typically seen from the Koreans, Persians, Indians, Burmese, Khmer, and Malay, can soak the arrows and still deal high amounts of damage to the archers.
Persian Paladins have an attack bonus against archers, and their War Elephants are far superior to the Vietnamese Battle Elephants stats-wise.
Aside from having Bombard Cannons, the Vietnamese siege line is exceptionally mediocre; any civilizations with decent cavalry, Eagle Warriors and/or better siege can defeat it. The Magyars', Huns', and Mongols' cavalry lines are excellent at countering Vietnamese siege, and the Italian Condottieri is also a threat to Vietnamese Bombard Cannons.
Vietnamese defenses can be easily defeated by civilizations with strong siege (like Celts, Ethiopians, Portuguese or Mongols) or a by good anti-building unit (like the Goth Huskarl and Hun Tarkan) thanks to the lack of Masonry and Architecture. Civilizations with good rams (such as Slavs, Celts and Ethiopians) pose a threat to Vietnamese archers, as the rams have high pierce armor and can garrison proper counters for archers. Civilizations with Siege Onagers and/or strong blast-radius siege (like the Celts, Ethiopians, Mongols, and Koreans) also counter Vietnamese archers effectively, especially if the Vietnamese player forgets to micro them.
The Vietnamese have no naval-specific buff, so any civilization with a better navy (like Vikings, Saracens and Portuguese) can easily defeat the Vietnamese navy. Shipwright is also absent from the tech tree, so the Vietnamese late-game navy is more expensive than that of civilizations with access to Shipwright.
As mentioned previously in the alliances section, the Vietnamese have more advantages when playing in a team game, due to their 3 team bonuses (one official team bonus, 2 technically team bonuses triggered by the player), so it logically follows that they provide better boosts in large teams, especially regarding Paper Money, since it gives 500 gold to each ally. In a 4 vs 4 game, they are technically converting 800 food into 1800 gold for the entire team, without a tribute fee.
In Nomad maps, they get a distinctive advantage due to their revelation of initial enemy Town Centers, as in this setting those will be revealed as soon as their opponents finish to build them, enabling the Vietnamese to adapt their future strategy even in this map.
In closed maps like Black Forest, Vietnamese have an advantage as they can wall up, then defend for a while with archers and finishing the game by spamming Imperial Skirmishers, Bombard Cannons and Battle Elephants. This advantage may also be applicable in maps like Arena, Fortress and Hideout, as in these, players start the game walled.
Having access to Battle Elephants, Bombard Cannons, Bombard Towers and tanky archers, they are well suited for Post-Imperial matches.
Knowing the exact location of the Town Centers is incredibly useful in Sudden Death modes, as the players are limited to having one Town Center, hence it's easier to locate and destroy the opponents' Town Centers.
In the Budapest map, the Town center revelation bonus applies to the additional Town Centers opponents have (in this map, every player starts with 2 Town Centers, and the Vietnamese revelation bonus applies to both).