Originally Posted by
PestWulf
I have some confusion that I'm hoping you folks can clear up for me in regards to how criticals are put together in combination with feats, enhancements and weapon mods.
If you don't mind me being a bit general...
The important stats of weapons are the base damage, the crit range and the crit multiplier.
Average damage per hit is equal to: base damage + (range * (multiplier -1)/19)
Burst effects will add: die average * (range * (multiplier -1)/19)
Seeker type effects will add: seeker effect * (range * (multiplier)/19)
Against mobs with fortification you won't get the full effect of crits, the bolded parenthesis will be scaled by: (1-fortification)
Generally things giving a static + to damage adds to base damage and things adding dice does not add to the base damage, with exceptions.
Burst, maiming and seeker effects are influenced by crits, static + to sneak attack damage from items/enhancements are not multiplied by crits.
Crits/threats
Out of the possible rolls of a d20, 1 will always be a miss, 19 will hit if you beat the targets AC. Out of the 19 hits, range will be threats if you beat the targets AC, a roll of 20 will always be a threat. A threat will be a crit if you successfully beat the targets AC on a second tohit roll, using the same modifiers as for the roll resulting in the hit and adding +confirmation bonuses such as seeker/kensai stuff. If you fail the threat roll it will still be a regular hit.
Getting a average
When calculating how much damage you do on crits you can eiter look at exactly what damage you do on the crits, what damage you do on the regular hits and then take the average.
Personally I prefer looking at how much damage crits do above regular hits. E.g. a rapier will do double damage on a crit, this can be seen as doing regular damage above regular damage. In short you can calculate the average from the crits by multiplying range by multiplier minus one and then divide that by 19.
A heavy pick and a rapier both have the same BD, a rapier has a range of 3 and a multiplier of 2, a heavy pick has a range of 1 and a multiplier of 4.
In 20 attacks, on average, the rapier will land 3 crits and the heavy pick 1. On the 2 hits that the rapier crits and the heavy pick dont the heavy pick will land 2 regular hits though.
Thus from those 3 hits the rapier will make crits equivalent to 2+2+2=6 regular hits and the heavy pick will land one crit for 4x regular damage and 2 regular hits. Thus the average damage of a rapier and a heavy pick will be exactly the same.
3*(2-1)=1*(4-1) in my words.
burst effects
A weapon with a x2 multiplier will have a icy burst of 1d10 and a holyburst of 1d6 while a weapon with a x3 multiplier will have a icy burst of 2d10 and a holyburst of 2d6.
In short it works exactly like the crits, range times multiplier minus one, divided by 19.
seeker effects
These are a bit odd since they scale directly with multiplier as opposed to with multiplier minus one, it is DDO specific so one can wonder...
In short, range times multiplier divided by 19.
enhancements
In the same way that you can calculate how much damage above a regular hit you do on a crit, you can calculate how much damage someone with e.g. kensai III will do above someone without.
Kensai: one times multiplier minus one divided by 19 additional base damage and bursts, multiplier * seeker bonus.
FBIII: two times two (+2 on 19-20) divided by 19 additional base damage and bursts, 4/19 * seeker bonus.
About the roll of 1
Now the jolly thing is that it is very easy to factor in how often you hit separately.
Just add the crit thingies to 1 and multiply with the average number of swings out of 20 swings that actually hit or crit.
Now since we used a base of 19 for the crits, in order to compare them to regular hits, we need to transform it back to a base of 20 in order to get a proper average, i.e. multiply by 19/20 or optionally just use a base of 20 from the beginning. Optionally we can be cleverer and just calculate crits to a varying base according to how many swings/20 actually hit. [edit:]Should have remembered to specify that this is in order for it to be easier to account for seeker type effects...
paste into your favorite spreadsheet:
Code:
range 6
mult 2
roll tohit 2
hits =21-B1
crits.per.hit =(min(B1;B4)*(B2-1)/B4)
base.damage.modifier =B4/20*(1+B5*max(B4+b7;20)/20)
seeker 6
Now that's for base damage so for bursts it'd be something like
Code:
burst.per.Hit =(min(B1;B4)*(B2-1)/B4)
burst =B8*(B4/20)*(max(b4+b7;20)/20)
Dunno if that just come out as a garbled jumble of nonsense...