Tactics, operations, and procedures
In AoE, "tactics" refers to maneuvers that individual units or small groups of units use to accomplish their objectives. "Operations" refers to maneuvers that large groups of units use, or that take place over a large part of the battlefield. "Strategy" refers to overall considerations. For example, one strategy in a multi-opponent situation would be to concentrate all your forces against one opponent. An operational plan would be to send the shock troops in first, supported by foot archers, and followed by combat engineers, while the cavalry harasses the rear areas. Avoiding the fire of an enemy archer would be a tactical maneuver. There are also other useful procedures that are non-military in nature.
In Age of Empires 2, the Pause feature has been modified so that you can take any possible game action while the game is paused. Most importantly, this means that you can analyze the situation and issue orders to any and all of your units, all within the instant of time determined by how long it takes you to press the F3 key. The tactics and operations that are possible using this feature are vastly more complex than in a standard RTS game. Run in this mode, the game functions as a turn-based game, with each turn being approximately one instant of time long.
As a specific example, what this allows you to do is check all of your villagers to see who is idle, reallocate villagers from one resource type to another, build a wall (and frequently, getting a gate to go where you want it takes an awful lot of effort, including building guide walls that are deleted immediately afterward), hunt efficiently (which is otherwise virtually impossible), check all of your idle military units, check your recent warnings, admire the scenery, check to see which units are in trouble, assign attack orders to all your units, assign flee orders to all your units (very, very important!), scout with a bunch of units, check all of your production buildings, and so forth, all at the same time.
In AoE, unless you micromanage your units in combat continuously, your casualties will always be enormous and unnecessary, because the default for uncontrolled units is to commit suicide, regardless of the combat stance you assign to the units. This is primarily because manual control is required for units to avoid unfavorable situations. Accordingly, your tactics will not be much better than driving your units into contact and slugging it out with the enemy. Certain types of units, such as cavalry archers, will simply not be able to function in a realistic way. In addition, many of your units should obey the general rule of avoiding enemy units, and the AoE automatic routines make no provision for this whatsoever.
Obviously, playing the game this way makes it a lot easier. When you play the game like this, it is generally possible to avoid any casualties, regardless of how hairy the tactical situation might be, and how many simultaneous engagements are occurring. Therefore, you may decide to assign the additional victory condition that you need to complete a scenario with zero casualties.
Playing the game using the Pause/F3 feature is not possible if more than one human is playing. But then, we are discussing campaign walkthroughs here.
All of the tactics discussed here assume the use of the Pause/F3 feature, as do all of the walkthroughs. Otherwise, they cannot be fully implemented, although the general principles always apply.
Missile weapon projectiles in AoE travel in straight lines, at least in the xy-surface. Without Ballistics, they head towards the target's position at the time of firing. With Ballistics, they head towards where the target is calculated to be, based on its velocity at the time of firing. In general, such projectiles can be evaded by movement.
Pre-Ballistics, it does not help to move towards the projectile, and it doesn't help much to move away. The most effective movement is at right angles to the projectile motion. Post-Ballistics, any evasion that avoids the projectile's path will do. Stopping a moving target usually works, and it is mechanically the easiest evasive maneuver to execute.
The path of a projectile always has some width, so successful evasion requires the target to move at least a certain distance. Fast units are clearly superior. Small units may be superior.
Evading hand-held gunpowder weapon projectiles may not be possible, because they move too fast. However, target motion may affect the hit probability.
Ships have the additional feature that it takes them some time to turn. They can only move or fire directly forward. Viking Longboats appear to emit a spray of arrows; it may be harder to evade their fire than that of regular ships.
Artillery weapons all have special features. One common characteristic is that their projectiles move quite slowly. Another is that they have an effective area much larger than any arrow. Trebuchets have a strongly plunging attack (and a minimum range), so moving towards them can be very effective. The landing area of a trebuchet's missile is highly random at the instant of firing, although deterministic after that.
In addition to or perhaps as part of the evasive maneuvers described above, a target may want to move towards or away from a missile unit. Consideration of the firing unit's reload time is important here.
Bait, Bait-and-Switch, and Ambush
AI-controlled units in AoE tend to fixate on particular targets. As long as they feel that they have a chance of catching the target, they won't change targets. This allows you to set one of your units up as a bait, while your other units are free to do something else. For example, proper use of the Bait tactic will allow two cavalry archers to beat two infantry units 100% of the time, which is the way it really should be.
Sometimes you want the pursuit to switch from one unit to another, i.e. you want to set up a new bait unit. Usually, this can be accomplished by attacking the enemy unit with the second unit while the first unit runs away. One example of the Bait-and-Switch tactic is when two monks alternate conversion attempts on one enemy unit. The enemy unit pursues the monk that is currently attempting the conversion, while the other monk runs away to gain some distance. Then they switch roles.
There are certain powerful enemy units, such as monks, that you usually don't want to engage in direct combat. A good way of dealing with them is to show them one unit (the bait), and while the bait is being chased, maneuver several other units into range and suddenly attack the pursuing unit with them. A perfect Ambush will kill the pursuing unit with one volley. This is a standard real-world tactic.
These tactics can also be used against human opponents.
It is often more important to hurt an enemy's economy than it is to destroy their current military units. The principle of the Raid is to have a military force operating in an enemy's rear areas, causing as much damage as possible before the arrival of a guard force makes it expedient to withdraw.
The most common target for a Raid is enemy villagers. As the game goes on, a player, especially an AI, will often send their villagers out of their base into unprotected areas, and it is important to seek out such opportunities.
Raiding is obviously a real-world operation, which may actually work better against human AoE opponents than AIs, because the AI is guaranteed to respond.
At all times, be prepared to convert the Raid into an Ambush. If the raiding force can beat the guard force, with or without an Ambush, be prepared to seize and hold that terrain.
Wall Maze Complex
Town Centers are impregnable in the Dark Age, assuming they contain villagers, of course. Properly emplaced Towers are virtually unbeatable in the Feudal Age. Castles are virtually unbeatable in the Castle Age, as long as you deal with enemy battering rams. But in the Imperial Age, properly used long range artillery dominates the battlefield. Towers become virtually useless, and even castles may not be worth building, because they are so expensive and so vulnerable. Static defenses in the Imperial Age are still absolutely essential, of course, but they need to be organized along different principles than in the previous Ages.
A wall maze complex is an arrangement of structures (a complex that is complex) that has characteristics of a maze and consists of walls and other defensive buildings. Its primary purpose is to allow the defender to engage attacking siege weapons on favorable terms. One key aspect of the WMC is that it is possible to walk from the outside to the inside without using a gate. Other than that, anything goes, but you generally want to ensure that the open route is as long and complicated and channeled as possible, and that enemy heavy artillery and battering rams never get to attack expensive buildings.
A human attacking a WMC will probably never expose his artillery, and will simply cut through the wall wherever he pleases. In this case, the attack will take a long time, and the defender needs to use that time in various ways, such as adding new wall layers in the path of the enemy. However, an attacking AI is quite liable to simply march along the open route, and the defender needs to take advantage of that fact.
Without micromanagement, your ships will perform very poorly in combat. Their low rate of fire and high damage output means that you should definitely micromanage them. The most obvious maneuver is to move a ship sideways when it is being attacked by another ship, although Fire Ships and Demolition Ships pose special problems. This forms the basis of almost all naval tactics.
In a Galley-on-Galley encounter, in principle, you would like to keep moving except during the enemy's reload time. If you have several Galleys fighting several enemy Galleys, then, most likely, the enemy will concentrate fire on some of your ships. In this case, your targeted ships should engage in evasive maneuvers in range of the enemy, while your other ships stand and shoot. Focus fire at all times.
Avoid encounters with superior numbers or even equal numbers of enemy ships. Try to fight in range of one of your castles. Definitely arrange to protect your docks with castles.
Sink enemy Demolition Ships instantly, or flee in panic. Sink enemy Fire Ships instantly. Any Galley targeted by a Fire Ship must flee.
It is very important to have villagers available to repair damaged ships.
The AI will definitely try to use some of these tactics, but is incapable of applying them all, or applying them intensely.
Cannon Galleons are extremely effective on beach front attacks, however they require ships such as fire ships to protect them in combat against other naval vessels. You must watch your cannon galleons at all times to make sure the enemy has not destroyed them, or if they have come to close to shore and are being destroyed by land units.
This section discusses all interactions between land and naval forces.
It is important to realize that the Cannon Galleon is one of the deadliest units in AoE2. If you have naval superiority, even locally, your Cannon Galleons will devastate everything for quite some distance inland. The only realistic defense is to move everything far inland. The AI is especially weak against Cannon Galleons, as it will leave lots of stuff standing around near the shore to be slaughtered.
Basic, unimproved Galleys have better stats than most land units, with more hitpoints than a Knight, pierce armor on par with the Huskarl, and attack and range on par with the unimproved Arbalest. Towers get attack bonuses against them, and a Castle's base stats are enough to stand up to them. The Galley line does twice it's base damage against buildings. Units that pose a danger to warships include Monks, massed Skirmishers, Bombard Cannons, Trebuchets, and Onagers.
Warships will generally clear a beachhead with ease. This does not necessarily mean that you can land there, but at least, you should be able to set up a killzone with your warships and keep drawing enemy units into it with your landing attempts.
Transport Ships provide a pretty safe haven for most of your units. Just don't let an enemy monk get near one of your loaded Transports!!!
Be aware that your trebuchets, once detected, will be attacked by just about every enemy unit in range. Be prepared to flee with them at a moment's notice. Do not - ever - engage in artillery duels trebuchet on trebuchet. That is a fool's version of counterbattery fire. Definitely engage deployed enemy trebuchets with your gunpowder artillery. Of course, feel free to use any other units as well. Small catapults are very effective against siege weapons, just don't expect to actually get to use them. Anyway, why are you building small catapults? Don't you have better units filling up your roster?
When protecting a trebuchet use they box formation on your units in the bottom left hand corner of the screen. Using range units such as Janissarys, archers, and etc. are recommended so that any unit that comes near the box will be killed.
Villagers can do many things in AoE, well beyond their basic economic activities. For example, they are actually your most powerful military units in the Dark Age, assuming you have Loom, especially considering how many you have. Just stay away from enemy Town Centers! Some of the things that they can do are rarely employed, and are definitely worth describing.
Dead animals in AoE deteriorate with time. Therefore, efficient hunting requires that hunter walking time be minimized, and multiple hunters need to work on each animal. Sheep cooperate with the mission, but wild animals do not. Deer will run away from humans, which they really should. But you want to kill the deer close to a depot, so you need to start the hunt by herding the deer towards the depot with your beaters. It is quite realistic, actually. Furthermore, you need to keep an eye on the hunters, because once a carcass is depleted, you need to start the beating all over again with the next deer. If you do not micromanage the hunters properly, you will wind up with a lot of rotting deer carcasses in random locations. Because of the large amount of micromanagement required, hunting is generally not worth the trouble.
In some campaign scenarios, you will need to hunt for food. The first objective is to make sure that the animal is entirely processed with the smallest number of trips to the depot. A competing criterion is that there is a maximum number of hunters that can conveniently work on an animal at the same time. You also want to minimize the amount of micromanagement required. Different animals have different properties, and the properties of villagers are not fixed.
With sheep, for example, which technically isn't hunting, a basic villager can collect 20 food in two trips, and the sheep will deteriorate by about 17 units in that time. Therefore one basic villager would be able to get about 55 food from one sheep. Two basic villagers would be able to get about 71 food from one sheep. Three basic villagers would be able to get about 78 food from one sheep. Four basic villagers can get about 83 food from one sheep. Five basic villagers can get about 85 food from one sheep. Actually, you can reliably get 86 if you do it right. If insufficient villagers work on a given sheep, the wastage can be substantial, but the returns diminish as the number of villagers increases. In general, you want to put as many villagers as possible on one animal until they start to get in each other's way. Five is probably the optimum number, because counting by fives is easier than counting by fours, and you need to keep track of what your villagers are doing.
Not including travel time, a basic hunter collects 35 food from one deer in one load, and the deer will deteriorate by about 22 units in that time. A Mongol hunter works 50% faster, and so takes 2/3 as long to collect 35 food, and the deer deteriorates by only 15 units in that time. One basic hunter would be able to get about 85 food from one deer if the travel time was very small. Two basic hunters would be able to get about 107 food from one deer if the travel time was very small. Three basic hunters would be able to get about 115 food from one deer if the travel time was very small. Four basic hunters would be able to get about 121 food from one deer, and there would only be one load. Five basic hunters would be able to get about 124 food from one deer. With deer, the travel time is usually relatively large. As with sheep, five is probably the optimum number of hunters working on one deer.
Wild Boar are quite dangerous. Do not hunt them unless you have Loom. Make sure to use a minimum of 5-7 hunters. Even so, the villager being hunted by the Boar needs a safe place to flee or a monk standing by, otherwise he or she will die. The use of Bait-and-Switch tactics are definitely appropriate.
Wolves are definitely dangerous. A normal Wolf will kill a villager prior to having Loom, primarily because the Wolf almost always strikes first. Accordingly, send your villagers forth in pairs if possible. Sometimes you encounter two or more Wolves at the same time. Two Wolves will kill a single villager with Loom. If you start the game in the Dark Age, it is probably worth investing some effort to exterminate Wolves. A pair of archers is adequate. Of course, once real military units are roaming the map, Wolves become extinct real soon.
Villagers can eliminate trees with this technique, but at least 2 units of wood must exist in your stockpile. When a villager starts to harvest wood, the tree must first be knocked down. As soon as the tree is cut down, which requires 2 or 3 chops, you can build a structure in that location, the cheapest being a Palisade Wall. The structure can be cancelled immediately, but the tree is permanently gone.
Villagers can eliminate trees with this technique, but at least one other resource type must be present in the part of the map that you have explored. When a villager is carrying a full load of wood, order him or her to start harvesting the other resource. All the wood is immediately discarded. This procedure allows the villager to continuously harvest wood from a tree, without needing to deposit the wood at a depot. It also works if you don't have a wood collection depot. In some scenarios, this is the only way to get past blocking trees. Unfortunately, it can work against you. For example, if a villager carrying a full load of the precious stone is attacked by a Wolf, he or she dumps all the stone and starts trying to "harvest" the Wolf.
Villagers, properly used, can be very powerful attack units. At the lowest level, they can attack enemy units and buildings directly, but that is not particularly effective after the Dark Age. In the Feudal Age or later, villagers can build stone walls, Towers, and eventually castles. The possibilities for the offensive use of stone and even wooden walls are endless, but primarily, they are based around the principle that walls are hard to destroy without heavy equipment. Not that it would ever be reasonably possible, but consider what would happen if you managed to put a wooden wall around an enemy Town Center in the Dark Age. Use your imagination.
If you can build a Tower in an enemy's home area in the Feudal Age (behind a stone wall, of course!), you have probably won the game. If you can build a castle in an enemy's home area at any time, he is almost certainly finished.
Always keep in mind that villagers can repair walls, buildings, ships, and siege equipment. Furthermore, garrisoned inside certain buildings, villagers acquire significant direct attack potential.
Accelerated wall construction
Walls are so hard to destroy without heavy equipment that even a partially built wooden wall has a serious channeling effect. After a villager has hammered only twice on a stone wall, for example, it already has several hundred hit points, plus all its armor. A partially built wall may have the full relevant effect of a complete wall, but can easily be put up 10 times as fast. So if you need a wall to go up really fast, lay the whole thing down, and force your Builders to rapidly move from section to section well before any section is fully built.
Towers are deadly early in the game. If you can build a Tower in an enemy's home area in the Feudal Age (behind a stone wall, of course!), you have probably won the game. A perfectly executed early Tower Attack against an AI runs somewhat as follows. In the Dark Age, locate an enemy's base, especially where they are collecting wood or ore. Advance to the Feudal Age as soon as REASONABLY possible. Time things so that a group (5 is a good number) of your villagers arrives in the enemy's base just as you enter the Feudal Age. Make sure that you have Loom. Savagely attack some of the enemy villagers with your own. They will run away or die. As soon as the enemy has no observation in the area where you want to build your Tower, build a stone wall around that spot. (For some reason, the AI does not like to see your Builders in its town, although it is not so hostile to other villagers.) Try to incorporate as much blocking terrain into your wall as possible. Leave some space between the wall and the Tower. Don't complete more than 10% of any wall section at this time. With the wall a fait accompli, the AI will generally ignore it. As soon as the wall is continuous, get all your villagers to work on a Tower. The Tower needs to be built before the victim is producing archers. When the Tower is finished, garrison your villagers inside and start machine-gunning the enemy villagers as they try to collect the resource that you have just denied them. Wait for them to surrender.
There are many subtle but important variations to this general process. The biggest one is to incorporate a gate into your wall. When the Tower and gate are finished, open the gate. Your Tower will immediately be rushed by hordes of enemy units. Of course, you will not let them at your Tower, right? Machine gun them as they stand around stupidly (or sadly, or hopelessly) outside your wall. Repeat as necessary.
An AI has no effective defense against a properly executed Tower Attack. It is hard to see what a human could do against it, except to do it to you first.
If you can build a castle in an enemy's home area at any time, he is almost certainly finished.
There are times when you have the clear upper hand against an opponent, but he keeps rebuilding so rapidly that you just can't seem to finish him off. You know the end is near when the enemy does not seem to have any more units that require gold to produce. However, you may still be facing hordes of spear infantry and skirmishers, which, despite being virtually free, are very effective against the primary attack units, heavy cavalry and cavalry archers. A human is liable to resign in this situation, but an AI will not.
The best way to break the enemy is to bring up a bunch of villagers and rapidly throw down a castle near their Town Center. You are unlikely to be able to do this, or even want to, any sooner, because it is a very risky operation until there are no more enemy heavy units. But once the castle is finished, you can safely bring up your heavy artillery, knock out their Town Center, kill all their villagers, and proceed from there.
Artillery vs. trees
Trebuchets can eliminate trees, but a direct hit is required. With a deployed trebuchet selected, right-click on a target tree. "Attack ground" does not work. Siege Onagers can also eliminate trees. The implementation is not uniform. Sometimes you can just right-click on a tree with a selected Siege Onager, but you can always "attack ground". In both cases, a large area is affected.