Siegecraft

To capture a camp, city or bridge that has been fortified with walls, you will need to conduct a siege. There are multiple components to conducting a siege including the assault, supporting fire and the blockade. A siege can be won either by reducing the target’s defences or the target’s morale to zero.

Walls
Walls were an integral part of defence in ancient times and formed a nearly impenetrable defence prior to improvements in siegecraft. Walls are essential to the security of a city and can be built as upgrades in the building tab. Walls provide defensive strength to a city and provide catapult fire from wall towers. The addition of a garrison will further strengthen defences and increase the rate of catapult fire, provided the garrison has food. The disadvantage of walls is that they cost gold to maintain. Additionally, non-native cities are more likely to revolt if they are given the protection of walls. The only solution is to provide a strong enough garrison to suppress the local population or to tear down the walls. Unwalled cities will be less likely to revolt and will require a much smaller garrison. Historical

=Assaulting the Walls= To reduce the enemy’s defences to zero, you will need to directly assault the walls. Select a combat unit and right-click on the target to move them into siege position. When the mouse is over the target you’ll see a preview of the available siege positions. Once in position, the units will begin to damage the target’s defences in proportion to their size and any siege bonuses. Some of this damage may be blocked by the city’s garrison. The garrison will also take damage and suffer casualties during the assault. While defending the walls, the enemy’s garrison will also be throwing javelins to attack the besieging army.

=Supporting Fire= In addition to directly assaulting walls, ranged units can be directed to fire at the target. Javelineers, archers, and even scorpions are not strong enough to damage walls, but they are very effective at shooting the garrison guarding them. Ranged units do not need to be in a specific siege position to attack the target. Since they do not damage the walls, ranged fire cannot reduce the target’s defences. However, they can be used to weaken the defending garrison before or during an assault, and their attacks will have a negative effect on a city’s morale which may be sufficient to force a surrender.

=Blockade= The difficulty of a siege is often determined by the strength of the target’s garrison. However, a garrison is only effective if it is properly supplied and you can prevent food and new recruits from reaching the garrison by blockading incoming supply lines. To block a supply line, simply move a combat unit anywhere along its length - it does not have to be near the target. If the target has water access, you may also need to block any maritime supply lines using warships or wait until winter when it is too rough to sail.

=Surrender= When sieging a city, you can also win by reducing its morale to zero and forcing it to surrender. This may be easier than destroying its defences, particularly if the city already has low morale due to faction hostility. Each unit of yours that is attacking the city will lower the target’s morale, as will starving its garrison. Finding and defeating any hostages that have been taken from the city will also significantly reduce morale.