Game mechanics questions for CA

[Puzz3D]

In MTW the formula is:

Each man has an attack value and defend value used in calculating the chance to kill his opponent on each "strike" in a combat cycle. Each man who is fighting gets one "strike" within a combat cycle, but can parry many times.

chance to kill = 1.9% * 1.2 ^ df
difference factor df = attack - defend + bonus
attack is the attack value of the striker
defend is the defend value of the opponent
bonus is any combat modifier that applies
charge is added in as a combat modifier

You can see all the combat modifiers in this thread Defensive Bonuses. Most of this comes from the Official MTW Strategy Guide, and some came directly from LongJohn who wrote the chapters on the game mechanics.

In RTW, the formula has become more complicated. We don't know the exact formula, and because it's more complicated, it's hard to determine empirically. Some tests I did indicate that the 1.2 constant has been changed to 1.1. That means the size of the steps in chance to kill has been reduced from 20% to 10%. The cutoff on df is + or - 20 in MTW. This has apparently been increased to 64 in RTW. In addition, there is a lethality factor for the melee weapon in RTW. I think this comes in as a multiplier on the base probability. Also, the shield now directly contributes to the defend value. but is directional as is the parry ability. From post 20 in this thread by Jerome: "Armour is applied as a modifier to attacks from any facing, while defense is a parry-style bonus on the front and right flank, and the shield bonus applies front and left flank. Missile weapons ignore defense." Missle weapons have a separate formula, and it is more straightforward. Tests in STW indicate that doubling armor cuts the kill rate in half from projectiles such as arrows. Height increases the range and accuracy of ranged weapons.