How many military units per city/population is recommended in Civilization IV?

Question

I'm looking for guidance in Civilization IV on how best to build a military that allows for the optimum mix of defensive capabilities with offensive ability (when needed) without having to sacrifice technological gains and city improvements.

Some background: I'm having difficulty balancing domestic output and city improvements with military strength and aggressiveness whenever I play at the Noble difficulty level or above. My preferred style of play is to not emphasize military strength, but instead to work on science and trade and city improvements. On the military front I build primarily defensive units with defensive city improvements (such as archers and walls in the early game). The problem I run into with this strategy is that usually by 0 AD or so there will be at least one civilization on the map that's got it out for me, despite my attempts at placating all of my neighbors. They'll send in a swarm of units, destroy my improvements, and take out a few cities. My only defense (sadly) is to buy/negotiate a peace treaty.

I've tried playing the opposite way - building a very strong military - but in doing so I usually have to sacrifice building workers/settlers at the rate I enjoy, which slows my expansion. I usually last a lot longer but by the mid game my civilization is behind most others when it comes to technology, city sizes, the breadth of my empire, culture, and so on. Also, this approach just isn't as much fun for me.

TIA

Answer 1

From my experience, 3 military is good enough for average defense, it allows you to hold out till you can reinforce.

But for your style of play, perhaps 5-10 would be better, you don't want to many as it causes slow down in tech etc..., but then you don't want to get crushed. You should have more on the outer cities and reinforce from your inner ones, I try to always have 3 minimum in all cities, but doesn't always work, then any bigger cities up it to 4-5.

If you notice your enemies normally attack you with massive stacks, the only way to counter those are with a large stack yourself. Have 1 large stack that walks between cities and does the attacking, then leave 3 units in all your cities for normal defense, remember if you suddenly get attacked at a choke point (hopefully you have one) you can always reinforce from your other cities, knocking them down to 1-2 stuff like that.

Answer 2

Notes: I played mostly on Monarch, took occasional tries at Emperor with mixed results there. Also, the weaker your defenses the more likely the AI is to declare war, regardless of how good your relations are so good relations alone do not suffice.

That said, I tended to keep 2 of the most modern defensive units in each of my cities while accumulating old ones. Thus, if I founded a city when I had archers and now have riflemen, my city would have 2 archers, 2 longbowmen, and 2 riflemen. Beyond 6 units I would either upgrade or delete the oldest ones to lower my army costs. On a border with an AI I knew was likely to attack me I would increase this to 3 during peacetime. I rarely built walls. You can generally notice a large shift of units within the AI's territory prior to it declaring war on you. Use this time to pump more defensive units and possibly try to appease them or get them in a war with someone else. Once they actually declare war, you can upgrade units in the cities they are attacking for a quick defensive boost.

If you are having trouble during the war itself there are a few possibilities. One is you can try to get other AI to go to war with them. This will take much of the burden off of you and weaken two AI at once. Generally though, if you are having trouble with wars that means your production is simply too low. How many cities are you founding? 6 or 9 are generally ideal for peaceful strategies. Are you keeping up with improvements? You want every worked tile to be improved. 1-2 workers per city will usually do a good enough job for that. Are you practicing city specialization? Are you just sitting back and defending? The best defense is usually a good offense. Building some stacks with 1-2 defensive units, and lots of attacking units and siege weapons will make for nice "stacks of doom" to repel the invaders with.

For more details on balancing your army and your empire growth, see this article.

Answer 3

I've successfully defended myself with as 2-3 units per city near borders and as low as 1 per city on the interior. I admit that needs managing of relationships and placating of angry neighbours, but I've found that often does the trick until you've researched the heck out of them and have a technologically superior army. The key thing is that you usually get some warning that a neighbour is going to attack you (like a tribute demand or something) in which case you can give them the tribute and start re-arming against the expected later onslaught. I'll admit that I've also lost inner cities to unexpected agressive barbarians too.

EDIT: I've recently started playing at higher levels - Prince and Monarch - and this no longer seems to work. My neighbours seem to be more frequently making surprise attacks with enough force to take a city before I can shore up its garrison.