I see how a lot of guides or dmg calculator excel out there have the bone chip/wep pot effect as a flat 20% multiplier (since wiki description says it gives +20% attack) and while true, that's not the whole story.
This is just a simple demonstration of how bone chip calculation works.
Base damage:
[Image: http://i.imgur.com/DUDOxQR.png]
Under pot:
[Image: http://i.imgur.com/pw8VXmF.png]
So far so good! we can confirm it gives +20% damage cause 1000 x 1.2 = 1200.
But now things get tricky... this is the BFO we will be using:
[Image: http://i.imgur.com/xstZpkr.png]
Cool, moving on...
Pot + BFO:
[Image: http://i.imgur.com/8TjLi77.png]
Wait... what? 1200 x 1.348 = 1617 how on earth are we getting 1700 dmg????
Well the solution is simple, bone chip/power pot ALSO increases the bfo multiplier itself. What does this mean? it means that instead of 34.8% bonus we are getting 41.76% (34.8 x 1.2).
So let's plug that in... 1200 x 1.4176 = 1701. It's not exactly 1700, but CLOSE ENOUGH. I assume this is because either
a)game rounds the char screen dmg up/down so 1000 wasn't the correct base to begin with.
or
b)you get 1 free magical dmg so stop complaining you nerd.
So in recap, bone chip/wep power pot boost not only your weapon damage but also the effect of battlefield overture separately. If we assume a 52% overture for calculation purposes, then using a bone chip will give you an overall ~28.2% damage increase and not just 20% like we are used to.
Bye.
[SPOILER="bonus stage"]Bone chip by itself does not affect firebolt, but it does still affect overture multiplier and your character screen dmg for the bfo calculation... so if you tried bone chip with firebolt and thought it was useless, use BFO and try again for prettier numbers![/SPOILER]
--- Merged Double Post ---
Also, if anyone has a better explanation/math/formula, etc please post and I will update, thanks.