Going to war is not an easy thing. it takes planning and practice.
You have to do a lot before you start. At a minimum you will need to do all of the following:
1. send in spies to see what you opponent has. They don't have to perform missions, just wander around and inspect the enemy army.
2. pick a city that you are going to capture. this will be based on the intelligence your spies provide. I prefer to pick the "low hanging fruit", which means grab the easiest city.
3. you will need siege weapons. lots of them. you if plan to take the city out in one turn, you will need enough seige engines to blow down the cities defense value (it's culture) and then bombard the units in the city. If the cities culture value is 50, then you will need enough catapults and trebuchets to reduce that to 0, plus you will want some extras to attack the city. I prefer enough of these to blow down the defense PLUS one seige engine for each garrison unit in the city.
4. build a force of your best units capable of capturing the city, add 50% for losses. here's an example, assume walled city built on a hill is defended by a longbowmen with CG2, a spearman CS2 and a warrior (no xp). All units are fully fortified. the longbowman's strength 17.7, the spearman is 12.8 versus mounted units and 8.8 versus everything else and the warrior checks in at 4.5. the total defense strength of the city is 31 if you attack with foot soldiers and 35 if you use mounted troops. So your minimum attacking force-
NOT INCLUDING SIEGE ENGINES-must have a combat strength of no less than 47. It must also physically outnumber the defender by at least one unit.
5. and then add a garrison for after you have taken the city. your garrison must be capable of holding the city AND suppressing any rebellions. I like to use (city size/3). Round up. Your garrison should include 2 spies and 2 missionaries if you have a state religion. there's no point in capturing the city if you cannot keep it, protect it and work it into your civilization.
6. build some cavalry units to pillage the countryside (i.e. destroy the improvements you don't want). i hate workshops and windmills, so I routinely pillage them.
7. build two smaller forces to cover your flanks; and
8. deploy extra spies in your home territory.
9. Take the city you want quickly and then consolidate your gains. Hold on for ten turns, then make peace with you enemy. repeat the procedure.
It's "OK" to win a small war, wait, win another small war, wait, win another small war and then finish your victim off at some later time.
Hoonak-Demon Warlord of Burbank
