The Pros and Cons of Siege Equipment
This article was written to highlight the Pros and Cons of the siege warfare equipment available to the player in Medieval 2: Total War, along with a section detailing the most effective use of the equipment. Siege warfare can be an ugly affair, but is unfortunately a core part of the game. It can be a difficult thing to master in Medieval Total War as units struggle to push through breached walls or gates and maintain stamina when fighting high on the castle walls. Hopefully the following article will set you up to be a fine Siege Warfare General.
Fast to build, simple to operate, can take down a gate fairly quickly. It does not use up ammunition, and can allow siege weapons (ballista, catapult, trebuchet, bombard, cannon, etc.) to concentrate on towers or walls. Also, a ram will open a hole in the defending wall (the gate), meaning all of your units can move through (unlike towers and ladders that only allow infantry units--no cavalry), with the exception of very large siege weapons (trebuchets). Finally, rams can be moved through gates to attack the second or third wall of a fortress or citadel.
Rams can be destroyed, meaning towers and archer units have a chance to cause the ram to burn with fire arrows. Ballista and Cannon Towers (settlement upgrades) can also deal direct damage to rams. Troops operating them will take significant casualties. Rams can only target gates of walled settlements. That typically means only one breach-point per siege (unless you march around to another gate). With the Kingdoms expansion pack, stone walls will also use boiling oil at gates, which can do damage to rams and their crews. For the sake of casualties, you normally want a cheap unit operating the ram. However, that unit will likely be on the assaulting vanguard through the gate, so using a cheap unit is risky. But then again, so is using an expensive unit...
Use rams on poorly defended settlements. They are especially useful on Towns because rams can destroy the palisade walls, as well as break open the gates. You can also use them on larger settlements (I do), especially if you have strong heavy cavalry you want to use, but be prepared to take losses. Typically I'll use cheap non-archer units on rams if possible, and start moving in heavy infantry when they the ram reaches the gate. That way the heavy infantry will be under fire for the shortest time but at the gate when it opens. Also build more than one ram, and be sure to keep an eye on it. There's nothing worse than losing track of the ram, only to discover it has been destroyed and your troops are sitting near the gate being cut down by arrows.
You can build ladders faster than any other siege equipment. Ladders are hard to hit, making them virtually immune to fire arrows, Ballista Towers, and Cannon Towers. This means they will always reach the walls if there are still men to carry them. Like rams, ladders can be moved to the inner walls of a fortress or citadel. Ladders are the only siege equipment that can moved around at a run. Finally, men climbing ladders reach the top of the wall much faster than siege towers because they have multiple ladders to climb (rather than the single ladder inside the siege tower).
Ladders provide zero protection against incoming fire, meaning relatively high casualty rates before reaching the enemy in a well-defended settlement. Also, because troops join the battle on a wall as soon as they get off the ladder, and because troops climb the ladders one at a time, it means troops have a harder time establishing a foothold on the wall. Ladders effectively make a bottleneck because it is difficult to achieve a critical mass of soldiers. Your men will almost always be outnumbered and often out-moralled, meaning very high casualty rates and sometimes outright failure to clear a wall of defenders. Finally, ladders cannot be used against Huge City walls.
Ladders are a sure bet and a risky proposition. By that I mean ladders are a sure bet to make it to the wall without burning down, but taking a wall with ladders will ensure many of your own troops die in the effort. Use ladders when you have superior troops (in quantity and quality) or if the settlement has Ballista or Cannon Towers. Do not be afraid to send multiple units up one set of ladders as you will need all the swords and spears you can get on top of that wall. Further, ladders will still be around to take the fight to a second or third wall if your ram burns down during a fortress or citadel battle. However, since troops can carry ladders at a run, they are great for exploiting an unforseen weak spot where a wall is lightly or completely undefended. They are the fastest way to take the fight to the enemy, so it's not a bad idea to keep some back, see how the defenders react to your siege, and then strike with a fast-moving ladder-based attack to flank defenders on the walls. Think of them as the siege equivalent of battlefield cavalry and you'll find some creative uses. But remember, they cannot be used against Huge City walls.
Siege towers provide the best protection for units marching to the walls for two reasons: they are big objects that block arrow fire, and defenders will probably be aiming at the siege towers--rather than the infantry--anyway. Siege towers also provide the most effective means of assaulting a wall because troops will attack the wall in a large group. Siege towers will only open up and release your infantry when enough have climbed to the top. This greatly increases their ability to fight and reduces your casualties. Finally, siege towers can be used against the highest walls.
Siege towers take the longest time to build of any siege equipment. Towers are big targets for wall towers and archers using fire arrows. Their size makes them especially vulnerable to Ballista and Cannon Towers. Siege towers can and often do catch fire, making them useless. Even worse, they can sometimes catch fire after they have docked with a wall, meaning the troops inside are goners. Ballista and Cannon Towers (settlement upgrades) can also deal direct damage to siege towers, in addition to incendiary damage. Siege towers cannot be used against a second or third wall in fortress or citadel battles even if a siege weapon has destroyed a section of wall (see discussion in posts below). Siege towers are slow to move and it takes a long time for troops to climb the tower, leaving it even more vulnerable to archer fire and giving the defenders more time to move troops into position.
Siege towers are the opposite of ladders: They are a risky proposition and a sure thing. It can be difficult to get all of your siege towers to the wall without having at least one burn down, so build extras. Remember: just because you have 10 infantry units doesn't mean you can only build 10 pieces of siege equipment. But once siege towers dock and get troops on the wall, you will be happy you took the extra time and effort. While the occasional catastrophe happens and you lose a unit when its siege tower burns down as they climb inside, a siege tower will rarely burn down after it reaches a wall. Therefore, it is the overall safest way to assault walls. Siege towers can also perform on Huge City walls that ladders cannot reach, which obviously makes them the more effective option in those cases. But remember siege towers cannot be used beyond the first wall of a fortress or citadel.
Like all things in the Total War series, there is no one "best" way to win. There are strategies that work better than others--and some that don't work at all--but all good strategies can be effective if done properly. I'm not going to tell you the "best" way to win as there really is no cookie-cutter answer. But I will say that as long as you keep the pros and cons in mind and you have the right information about your enemy, you will likely be successful in your sieges. Tailor your use of rams, ladders, and siege towers to the situation and you will be victorious.