This is Papi's execllent auto damage post located at http://www.celtic-heroes.com/forum/viewtopic.php?f=75&t=29643 posted on Thu Apr 04, 2013 1:53 pm. I am copying it here in it's entirety in case it ever gets deleted from the forums.
[quote="Papi"]Placing this here because the version sections keep getting archived.
The formula for auto damage has slightly
changed but here is the result. It is
accurate to +-1(thank you Dog for helping me find my mistake). I only took 300 data points, would have done
more but they turned off the fast ability leveling feature so was limited on
whatever abilities my toons already had.
Auto Damage = (0.158 *(STR)^0.5 + 0.061
* (Ability )^0.5+0.95) * PhysicalDamage + ElementalDamage
The reasons there are slight differences
between these formulas and the actual values is because I am assuming a simple
mathematical formula solution for all these solutions. In programming there are many step functions
and lookup tables and case statement type solutions that can create any shape a
curve you desire. Also, a formula
requires processor time while a lookup table does not but does take up some
memory. I am assuming OTM uses the table
approach to make the game run faster.
What this means is that the table can have an error in it or they
rounded up instead of down or any number of anomalies which can not be
predictable without exhaustive testing.
Short answer STR gets the most bang for
the buck under 400. After 400 it still
helps but not as much.
Stop reading here unless you want to
understand what the formula means.
Ok let me break it down for you into
pieces
The basic damage is of the form y = mx+b
straight from your algebra class.
y is the autodamage
x is the physical damage of the weapon
b is the elemental damage of the weapon
m is the slope which in our case has
three parts to it so
Auto Damage = m * PhysicalDamage +
ElementalDamage
m is defined by your STR and your Weapon
Ability score (and where all the fun is)
So what does m tell us?
m= 0.158 *(STR)^0.5 + 0.062 *
(Attack)^0.5+0.95
m= STR piece + Ability piece + .95
If you are first level with a 5 STR and
0 Ability then m is 1.3
So you will multiply whatever weapon you
have by 1.3 and get the damage it will do.
With a 500 STR and a 1300 Ability m will
be 6.68 (3.53 from STR, 2.2 from
Ability , and .95 for the weapon itself)
Well we have a little control over
Ability. We level it as best as we can
but for the most part we have a lot of control over our STR so lets look at
that.
STR piece = 0.158 *(STR)^0.5
or if you prefer
STR piece = 0.158 *SQRT(STR)
[img]http://i1055.photobucket.com/albums/s511/mageguild/AutoSTRPiece_zpsdb35d82f.jpg?t=1365104474[/img]
I plotted straight line that roughly
approximates the high end. In essence
after 400 STR every 5 points gives you about a 1.5% increase IN STR MULTIPLIER
ONLY.
Since the STR piece makes up about half
the total multiplier that means only .75% increase for your total max damage.
So I your stat page says you are doing
600 damage. Should I put more into
STR. Well the first question is how much
of that 600 is physical damage vs elemental damage. The multiplier only effects pierce, slash and
crush, not fire ice magic or poison.
So you have to add up all your gears
elemental damage and put that aside and only look at the physical piece.
Hope this helps.
Short answer STR gets the most bang for
the buck under 400. After 400 it still
helps but not as much.[/quote]