ElJoepo said:
Sacrificing high experienced units to crack open the first defender is not always a bad thing in my opinion, for example if you play an aggressive civ (cheap barracks + first +10% strength upgrade) you will almost start with veteran units. (eg: lose 2 normal swordsmen or just 1 experienced one to crack open a city)
Yeah, I forgot about that exception. When you are face with a situation where regular troops have a 31% chance of success, but Elite troops have a 68% chance, you should use the elites. Generally this will be because you were facing an especially strong defender, and you want it taken care of as cleanly as possible. Even if you lose your elite, a regular should get promoted up.
ElJoepo said:
Check which units are close to upgrading, and make sure they win. They heal after upgrading so they can give an extra punch next round which can just give you that edge you need

Also always build more then you think you need
Yes, another good tactic. Making your "on the edge" troops do the winning will earn you another promotion, which will make your troops stronger sooner, as well as cutting your healing time in half, so you won't lose too much pace in your assault.
Kalleyao said:
Stack of doom is
not a tactic!!! SOD is what happens when you already have military supremacy, and your opponent has no artillery. If you are referring to marching overwhelming numbers of troops against an enemy city...then that's called "assaulting".
The-Hawk said:
One thing I would add... don't cut it too fine. When you decide to attack, you really want to carve them down in one turn. Specifically, you want to kill as many of the wounded as you can. If you do not have enough units to "cycle" through their defenders twice (first time to wound or kill every unit, second time to kill the wounded), then you should think twice. Otherwise you might simply be promoting their units and making harder for the next time. I always try to have a unit with Medic 1 in my stack and won't attack with it unless the odds are very high. This way, if the defender stack survives past a couple of rounds, I will be healing my units and can keep the pressure on. Nothing worse than grinding away only to get behind the curve and have to give up (and then watch all the defenders promote and heal). No half way measures when attacking!
And that's basicly where I got my statistics from for how many troops you should bring on the assault. Whenever you attack a city, make sure that you concentrate all of your attacking into a single turn, and make sure that you
win. Never fight a battle unless you are going to win it (or will profit in some less direct way).
Always attack with superior numbers, in situations that are most advantageous for you, and avoid fighting in disadvantageous positions with a limited number of troops.
To illustrate the "superior numbers" advantage, let's take a look at a sample battle here, of 2 Axemen vs. 3 Axemen, all of equal strength:
Axe-A1 vs. Axe-B1 --> Axe-A1 wins at 40% health
Axe-A2 vs. Axe-B2 --> Axe-B2 wins at 20% health
At this point, it's been an even trade, but then the second-wave comes in.
Axe-A1 vs. Axe-B3 --> Axe-B3 wins at 85% health
And thus, numerical superiority turned what at first looks like a 1-for-1 battle, into a 2-for-1 victory. The principle is that the first wave of units softens up the defenders, and then the second wave cleans up. To be properly safe, one should generally bring to battle twice as many troops as the enemy fields. In cases where the defender is significantly stronger than you, it may in fact require 2 or more waves of "softening up" before they fall.
So, when you assault, bring enough troops to cover your losses, and bring enough troops to
win. If you can't field 2v1, you can't win the war (but still might not lose it). But just remember: Every battle that you win means less troops for your opponent, so your ratio will get steaadily better, even if you started off at a disadvantage.