As far as this goes I believe that the overkill damage works something like this a Warrior has a WW that deals 100,000 to AC 0 no spells. The warrior deals enough damage to kill the main target, then 20% of the damage leftover is dealt to any animal adjacent to the one killed.
Here is my theory for a formula:
({ (D)-[(V)*[(100*TS)/(100+TAC)] }*.2)*(100+OAC/100*OS)
D=Damage done by vita attack against AC=0 (Can be calculated
Here)
V=Target creature's vita
TS=Target's sanctuary value (1 if no sanc, no sleep, .7 if doze no sanc, .5 if sleep no sanc, 2 if sanc no sleep, 1.7 sanc+doze 1.5 sanc+sleep)
TAC= Target Armor Class
OAC= Overkill target AC
OS=Overkill target sanctuary value (1 if no sanc, no sleep, .7 if doze no sanc, .5 if sleep no sanc, 2 if sanc no sleep, 1.7 sanc+doze 1.5 sanc+sleep)
I'm relatively certain the formula is correct, what happens is you would deal so much to AC=0. Instead of calculating AC for the target the Target's Vita is modified to fit how hard they are to kill (to avoid a third AC and sanc conversion). The remaining power of the attack is then taken down by 20% and then the AC of the Second target is applied to the remaining damage. This is because each Overkill target applies their own AC and Sanctuary modifiers to the attack
Here are a few examples of how it works:
A warrior with a Whirlwind that deals 100,000 damage to AC=0 no sanc no sleep. To a target with 5,000 50 AC No sanctuary and has sleep. The second target has -85 AC, and Sanctuary.
({(100,000)-[(5,000)*[(100*.5)/(100+50)]}*.2)*((100-85)/(100*2))
(100,000-5000*(50/150))*.2
100,000-15000=85,000(So the Target took away 15,000 damage credits(points of damage to AC0)
85,000*.2=17,000(if we left OAC at 0 this is what would be dealt)
17,000*[(100-85)/(100*2)]=1275
Damage dealt to Second target 1275.
Against a truly weak opponent essentially no Vita, and an opponent at 100ac with sanctuary.
({(100,000)-[(0)*[(100*1)/(100+0)] }*.2)*(100+100/100*2)
100,000*.2*(200/200)= 20,000(20% of damage because killed creature had 0 vita)
According to Ixeus' Nexus Calculators a 100,000 attack against the same opponent deals 100,000 damage, meaning that overflow is 20% of damage in excess of killing the first opponent.
PureLight
P.S.
Credit goes to Tynan for figuring out the actual formula, all I did was apply how sanctuary,AC and sleep affect the formula.
Tynan explained best it for people who like numbers less than I do on the Comm board with this:
QUOTE
Overflow Damage = (Damage Done - Damage Needed)*0.2