armor piercing

[RRMike]

I've noticed that with missile units there is an armor modifier. .7 or .3 or whatever, and I assume you would multiply the base armor by this amount to figure out how much protection the armor would offer against that missile.

How do melee AP attacks work? Do they completely negate the armor or is there a standard modifier? I haven't really found anything listed in the unit guide that says anything about it like the missile units have so I assume it is the same for all AP melee units.

[drone]

The official guide had the formula listed. For AP melee weapons, the target armour is modified as such:

• When attacking infantry, AP weapons make the target armour = (Armour - 1) / 2.
• When attacking cavalry, AP weapons make the target armour = (Armour - 2) / 2.

The shield modifier is not used in this calculation, it is applied after the AP effect.

[RRMike]

Thanks Drone. I finally found it here:

http://www.totalwar.org/strategy/twug/A.html

Along with the answer to a question I was just about to ask about shields.

[bunt0025]

The official guide had the formula listed. For AP melee weapons, the target armour is modified as such:

• When attacking infantry, AP weapons make the target armour = (Armour - 1) / 2.
• When attacking cavalry, AP weapons make the target armour = (Armour - 2) / 2.

The shield modifier is not used in this calculation, it is applied after the AP effect.

via http://www.totalwar.org/strategy/twug/A.html :
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The formula for working out the armour piercing bonus against a specific target is as follows:
(target armour - 1)/2 = bonus added to attack.

That means that AP gives a bonus of +1 to attack at enemy armour of 3-4, +2 at 5-6 and so on. Upgraded armour is affected by this, effectively making added armour only half again as effective as it was supposed to. Cavalry armour affected by AP starts at 4 due to the horse/camel itself being a point of armour and still a soft squishy thing.
So really while AP units are more effective against heavily armoured units it doesn't mean they will do poorly against unarmoured units, they just don't get the bonus.
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This guide's explaination has always been what I've taken as fact. When did the cavalry change occur? With a patch or has it always been that way or what? I might have to start with mods just to undo this headache.

[drone]

To the best of my knowledge, cavalry armour has always been treated as a +1 effect for both armour piercing and desert fatigue calculations. What I posted was in the official guide book (the BradyGames guide, made back in the day when guides actually reflected what the game was like), and matched what frogbeastegg wrote in the guide.

I'm not really sure why you consider it a headache. I've never been all that convinced that the kill chance computation is based on integer values, there are too many other battle engine adjustments that suggest fractions are used. The attack/defense bonuses for difficulty setting and the armour piercing with missile weapons use percentages, and I'm guessing the height modifier for melee is also a percentage bonus.