The XML file you're looking for is items.xml. Example for Iron Fireaxe is below.
Code:
<passive_effect name="EntityDamage" operation="base_set" value="15.1"/>
...
<passive_effect name="ModPowerBonus" operation="perc_add" value=".10" tags="EntityDamage,BlockDamage"/>
...
<passive_effect name="EntityDamage" operation="perc_add" value="-.15,.15"/> <!-- random EntityDmg -->
<passive_effect name="EntityDamage" operation="perc_add" value=".1,.5" tier="2,6"/> <!-- tier bonus -->
If I'm reading that correctly (50/50 odds of that), it could be written as:
- Iron Fireaxe has a base entity damage of 15.1
- Upon item generation, a random amount between -0.15 (-15%) and +0.15 (15%) is added
- Each additional level adds between 0.1 (10%) and 0.5 (50%) entity damage (this part does not seem to work this way tho)
This should result in the following ranges (but the game does not match up with this):
[table=width: 300, class: outer_border, align: left]
[tr]
[td]Level[/td]
[td]Min[/td]
[td]Max[/td]
[/tr]
[tr]
[td]1[/td]
[td]12.835[/td]
[td]17.365[/td]
[/tr]
[tr]
[td]2[/td]
[td]14.345[/td]
[td]24.915[/td]
[/tr]
[tr]
[td]3[/td]
[td]15.855[/td]
[td]32.465[/td]
[/tr]
[tr]
[td]4[/td]
[td]17.365[/td]
[td]40.015[/td]
[/tr]
[tr]
[td]5[/td]
[td]18.875[/td]
[td]47.565[/td]
[/tr]
[tr]
[td]6[/td]
[td]20.385[/td]
[td]55.115[/td]
[/tr]
[/table]
When I tested this out, I actually got results that are in line with this behavior for #3 above:
3. Each addtional level adds 0.1 (10%) entity damage (instead of a range of 10-50%)
That would give us this range:
[table=width: 300, class: outer_border, align: left]
[tr]
[td]Level[/td]
[td]Min[/td]
[td]Max[/td]
[/tr]
[tr]
[td]1[/td]
[td]12.835[/td]
[td]17.365[/td]
[/tr]
[tr]
[td]2[/td]
[td]14.345[/td]
[td]18.875[/td]
[/tr]
[tr]
[td]3[/td]
[td]15.855[/td]
[td]20.385[/td]
[/tr]
[tr]
[td]4[/td]
[td]17.365[/td]
[td]21.895[/td]
[/tr]
[tr]
[td]5[/td]
[td]18.875[/td]
[td]23.405[/td]
[/tr]
[tr]
[td]6[/td]
[td]20.385[/td]
[td]24.915[/td]
[/tr]
[/table]
I tested about 40 each of Level 5 and Level 6 axes and the numbers all fell within those ranges. Due to the way it does the calculations, it is not an even distribution. For example most Level 6 axes fall in the 22 & 23 buckets.
Note that the above is for entity damage not block damage. I expect the math works the same for both.