8. Tips and tricks
There are also several tricks that one may utilize in order to help defend against assaults when in castles. I have summarized them below.
Reverse Psychology
Sometimes, though not often, I will opt to place artillery inside my walls. Generally, trebuchets and mortars are the only weapons with arcs of fire high enough to get over the wall, but used right, and they can be deadly. They can destroy artillery and siege weapons far easier than towers, and at greater ranges. Cannons, serpentines, ribaults, and basilisks can be used inside the walls, though only for street fighting. Bombards and grand bombards are not recommended.
Regicide
The enemy general is the most valuable enemy unit, especially in siege warfare. Attackers are touchy when assaulting stone in addition to men, and are therefore easy to rout. Concentrating on the general, so much so that you waste far more troops than you kill, can be used as an atom bomb to enemy morale, and will work when all other hope is lost.
Catapult Banzi
Enemy artillery is often the most effective weapon they can use against you, and what's worse, is that they are generally out of range. By sending your cavalry out, you can try to rout their weapons before they can severely damage your walls. Be forewarned: your cavalry are almost certainly screwed, and even so, chances for success are not good. This is not a job for your general.
Suckerpunch
An interesting method I sometimes use can help weaken the strength of enemy battering rams. As the ram nears my gates, I will send men out to attack the unit arming it. The ram will stop, and them men will start fighting, giving my archers time to get rid of the ram. Also, if your men make it back inside, your gates are still serviceable.
Mousetrap
An addition to the suckerpunch method, you can attack and then draw the enemy inside your walls. Then, after a sufficient amount are separated, attack at the end of their column, separating them from the gates. If you do this right, the gates will shut, and then half their army is between your pissed off troops and a hard place.
9. Preparation
Preparing for siege is also important. If I notice that the enemy is about to attack me, I will start preparing as soon as I notice. This often will be when they attack, which is a little late, but if I happen to figure it out beforehand (hint: large enemy stacks hanging around your cities is a good harbinger of doom), I will do some things to prevent my ass from being kicked. This consists of making repairs and retraining and recruiting last minute units. Do not build anything that takes more than one turn, because if you do, it won't be finished in time, and production stops during a siege. There are some good units to have, and there are bad units. Try to keep them straight:
Examples of good units:
Heavy infantry
Archers
More archers
Some light infantry
High-trajectory artillery (Trebuchets, mortars)
Examples of bad units:
Cavalry, for the most part
Low-trajectory artillery
Lots of light infantry
Now why are some good, and some bad? Heavy infantry can hold key positions far easier than light infantry, which is only really effective when moshed. A mosh pit of infantry can be demoralizing to an enemy, but is particularly dangerous; if your general is not present in the mosh pit, one rout can start a chain reaction that will destroy you, and if your general is in it, and he dies, the battle is pretty much lost. Heavy infantry are also very effective on walls. Gone are the days of RTW when units routed on walls they fought to the death; now, your men will actually rout. This is good for the defenders, because it means that the enemy is far easier to get off the wall, but it also means that stronger units must be placed on the wall. Also, stronger units will outlast the enemy, and sieges, even in battles, are often simply a waiting game. Whoever routs first will lose, and the longer your men can hold out, the better.
10. Types of defense
There are thee main types of defense when holding off an enemy army. These three types are a Static Defense, a Dynamic Defense, and a Composite Defense.
Static Defense
A Static Defense is the most simple of all defense strategies. When one is utilizing a static defense, one simply places his units directly in front of the enemy, and does not give them orders. This works fairly well, most of the time. It also has the advantage of not requiring you to give your men orders, and this is very important, as I have pointed out in my previous section on the stupidity of your soldiers. However, static defenses can have problems, especially when the odds are particularly out of your favor. A static defense cannot react well, and will not have a reserve. While it may have several lines of defense, it is not conducted with a fallback plan in mind. A static defense can basically be termed as a fight to the death, since there is no room for error. They must be meticulously planned, but if done right, can be very effective at crushing enemy troops at minimal losses. The problem, of course, is that you must be there to meet every single enemy attack, and you only have enough men to do that when the odds are not far out of your favor. Even so, they maximize the chance of victory, though they increase the chance of heavy casualties being sustained.
Dynamic Defense
A dynamic defense is a very hard thing to pull off, and relies a lot on luck. The only time you really need to use a dynamic defense is when you have a lot of cavalry units. Cavalry works far better under charge conditions, and so it is better to place your cavalry far from the gates, so that when the enemy breaks through, you can meet them in stride. Placing infantry around your gate in an ambush is another method; a dynamic defense usually relies on a small force at the wall, followed by a large, strong reserve that is brought up where it is needed. This strategy is only very effective when one has a lot of cavalry, and is not recommended otherwise.
Composite Defense
A composite defense combines both elements of a static defense and a dynamic defense. Composite defenses often result in higher enemy casualties than static defenses, but are far riskier. Composite defenses are most effective in citadels and fortresses, where your men can fall back to a second line of defense. A composite defense will have a moderately sized reserve, with static defense positions interwoven. When utilizing a composite defense, one is at liberty to do more things - however, if you make a mistake, you are often far more screwed than you would under a static defense. The advantage of a composite defense lies in its ability to accept odds. When the odds are far out of your favor, and you do not have many mounted units, a composite defense can be utilized to help secure victory.
Sallying forth
Sometimes, it is best to sally forth. This sort of defeats the purpose of the siege, so I do not do it often. However, sometimes it is a good idea, under specific purposes. The obvious time for this to happen is when you are about to surrender, and it is your only hope. A good tool there is the mousetrap method, which I described earlier, though this does not always work. However, another important time to sally forth is when two armies besiege you, and your general can conduct a night attack. Attacking at night will remove half the enemy reinforcements, and you can therefore greatly increase your chances of victory. When sallying forth, send your cavalry out first. Then, send out your infantry, and get them in formation before assaulting. Sometimes, it is a good idea to place your units in column formation. That is a good idea if you are planning on fighting within the indent that forms in your wall around the gate. However, if you are not planning on doing this, move your men into a standard formation, and fight it as if the walls were not there.