Some Power Attack Math!

[Aramus Lex]

Ok, I've been all over the interwebs and haven't found a consensus on what ratios Power Attack should have when combined with various abilities. Here's some ideas I've seen:

1-H PA: 1-1
2-H PA: 2-1

Leap Attack:
1-H LA PA: 2-1
2-H LA PA: 4-1 or 3-1? Errata says 100% more bonus damage from power attack but also makes note that the 2-H should stay at 3-1. Yet many people claim it is 4-1.

Improved Power Attack:
1-H IPA: 1.5-1
2-H IPA: 3-1

Improved Power Attack and Leap Attack:
1-H LA IPA: 3-1
2-H LA IPA: 6-1 or 4-1 (if you're using the premise that the base bonus damage is only what you subtract from your BAB)

Supreme Power Attack:
1-H SPA: 2-1
2-H SPA: 4-1

Supreme Power Attack and Leap Attack:
1-H LA SPA: 4-1
2-H LA SPA: 8-1

The numbers listed first are what make the most sense to me and make the math the easiest. What I do is basically say that you have your base power attack and the leap attack doubles (+100% bonus damage) the ratio. IPA increases the power attack effiency by 50% and SPA does the same but by 100%.

Where I know I may be incorrect is in the calculations with leap attack.

Like I said, I know these posts are everywhere, but no one can clearly explain how they obtained all the results. If you know how this works, kindly fill out the table as I've posted above and let me and the rest of the community know how you calcuated each element if there's controversy.

Thank you so much for any time you put into this!
Aramus

[Tesla_pasta]

the player's handbook explicitly says that multipliers stack as if adding an additional 100% damage, so x2 x2 gives total x3 damage. The ambiguity comes from some thought that the multiple rule only applies to crits and anti-charge weapons. I'm pretty sure RAW, it applies to power attacking as well. therefore, supreme power attack and leap attack give a 5-1 ratio.

[Aramus Lex]

That's actually what some of my original calcuations concluded. Basically, that Leap Attack was additive.

2-1 ratio from 2-H + 100% SPA = 4-1 ratio. Leap attack adds in 100% of the sacrafice in BAB so in essence, adds a flat 1 to the ratio for a total of 5-1.

This makes sense and may be the way I go for convincing my DM to even allow me to do this. Though again, I've seen ratios that included 6-1, 8-1 and even as high as 12-1 argued as correct.

[killianh]

math is right. Another good feat to add the the combo is Combat brute. It gives you "X3 to damage when using a two handed weapon" with power attack. With the explanation they give for the feat it would be another 1-1\2 ratio for 1 H or 3 for two handed taking the 2H to 11:1

[Andezzar]

Leap Attack:
1-H LA PA: 2-1
1-H LA PA: 4-1 or 3-1? Errata says 100% more bonus damage from power attack but also makes note that the 2-H should stay at 3-1. Yet many people claim it is 4-1.This is because using a weapon with two hands does not double the damage from power attack but gives you a different exchange rate (2-1). That this is double the exchange rate of power attack with a one-handed weapon is purely incidental. The +100% from errata further clarifies that the extra damage from leap attack is not a doubling but another source of extra damage.