Note: This only works for settlements with a Large or Epic Stone Wall. At least two Archer unit and at least one Onager, if possible, are required. If not, just having the Archers is fine. You also need Infantry and Cavalry; however if you have the ability to build a large or Epic Stone Wall, then this should be easy. First, array your archers onto the walls either side and on top of the gate if possible. After that, place your infantry in a semicircle around the gate, taking care not to block the entrances to the walls. If you have Onagers, place them far enough back for them to be able to fire over the walls. Cavalry should be placed at strategic points as you see fit. When the attacking army begins, look at the siege engines they have. If they have Siege Towers, tell your Onagers to fire flaming ammo towards the towers. This will set them alight and raze them, rendering them useless. If the enemy has a Ram, tell your archers to fire flaming arrows onto it. This will also raze the ram, making it useless. If the enemy has Onagers, look at where he is aiming and redeploy your troops to the weak location. If the enemy breaches the gates, he should be running directly into a ring of swords, backed up by cavalry. If he gets onto the walls, simply deploy a unit onto the wall, with archers behind. This method will stop armies much larger than the army inside the city. For this to work well, you need about twelve units: two Archers, one Onager, five Infantry and about four Cavalry.