Power Attack Calculator

[Peregrine]

After tinkering with various mathematical models of feats and their effects on damage dealing in combat, I've come up with something that might, maybe, possibly be useful.

Peregrine's Optimal Power Attack Calculator (http://members.westnet.com.au/perey/optimal-power.html)

Okay, so maybe it's not so useful, not in the sense that you could sit down in a game and use it (you need to know the enemy's AC, and if it changes so do the results). But it's kinda cool and helps illustrate some interesting facts about feat power.

It lacks any sort of legend or explanation, though...

The fields across the top let you enter your BAB, your weapon stats (dice, damage bonus, crit range and multiplier, and any extra damage dice that aren't multiplied on crits), and whether you're using one hand or two.

The numbers across the top give the roll you would need to hit an opponent, before applying power attack penalties. The numbers down the left show the amount you're power attacking for. The numbers in the table are the mean damage values you'll deal per attack.

Green cells are possible attacks; grey cells aren't possible (because your BAB isn't high enough to use that much power attack); orange values are possible attacks, but they need an attack roll so high that some of your critical threat range actually misses (so your threat range is effectively lower).

Values in red are the optimum. Values in pink would be the optimum, if they weren't in the grey region.

Oh, and it doesn't work in Internet Explorer 6. Likely not in version 7 either. (Tested in Firefox and Opera, other browsers stand a good chance of working too.)

Comments?

[Jack Mann]

I can't load the page.


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You were denied access because:

Access denied by access control list.

[Piccamo]

It loaded fine for me.

[FireSpark]

Oh, and it doesn't work in Internet Explorer 6. Likely not in version 7 either. (Tested in Firefox and Opera, other browsers stand a good chance of working too.)

Comments?

Quite the correct statement unfortunately.

Though I don't really see the need for a table for this purpose. Considering that Power Attack adds damage at a flat rate (albeit depending on whether your wielding one-handed vs. two-handed), determining how much to convert is really a simple X-Y=Z question in regards to the AC you can hit.

Just my two cents.

[Miles Invictus]

It's not quite that simple. Let's say that you are a first-level Fighter with 16 Strength, wielding a Greatsword. You have an attack bonus of +4 (+3 from Strength, +1 from BAB) and your base damage is 2d6+4 (average of 10), right? You can Power Attack for 1, increasing your base damage to 2d6+6 (average of 12).

Now, say you go up against an enemy with 23 AC. If you use Power Attack, you'll do an average of 12 damage per hit, but you only hit on a natural 20. If you don't power attack, you only do 10 damage per hit, but you can hit on a 19, which means you hit twice as often. Over time, you'll do roughly 66% more damage than if you used Power Attack.

[Jack Mann]

Finally loaded for me. I'm using Firefox, by the way.

One problem I see here is that it isn't taking every factor into account. For example, your total attack bonus. A 14th level fighter with 10 strength and dex has the same attack bonus as a 9th level fighter with a 20 strength (they've got other problems too, of course, since they clearly have no magic items to boost them, but that's their own problem). However, the 14th level fighter not only can power attack for more, he has iterative attacks to take into consideration. And you can't just put in 9 for the 9th level fighter, because his chance to hit is better than that, which would skew the results for when he should power attack.

To be truly useful, your BAB calculator needs a way to incorporate both iterative attacks and higher attack bonuses. This (http://www.greatplayground.org/tools/cookiepowerAttack) is currently my favorite power attack calculator, since it allows you to simply set your attack routine. This is especially useful if you have, say, haste, which grants another attack at your highest BAB. It has its problems (can't interweave different kinds of attacks), but it's generally pretty good.

[GenLee]

It's not quite that simple. Let's say that you are a first-level Fighter with 16 Strength, wielding a Greatsword. Your BAB is +1, and your base damage is 2d6+4 (average of 10), right? You can Power Attack for 1, increasing your base damage to 2d6+6 (average of 12).

Now, say you go up against an enemy with 20 AC. If you use Power Attack, you'll do an average of 12 damage per hit, but you only hit on a natural 20. If you don't power attack, you only do 10 damage per hit, but you can hit on a 19 or higher, which means you hit twice as often. Over time, you'll do roughly 66% more damage than if you used Power Attack.

Umm, not quite. An L1 fighter with 16 Str has +1 BAB, +3 for Str in melee, so he hits AC 20 on a dr of 16+ (or 25%). Also, the average of a d6 is 3.5, so 2d6+4 is an average of 11 damage, and 2d6+6 is average 13.

vs. AC 20, the same guy has
no PA: 25% to hit, avg. damage 11.
with PA: 20% to hit, avg. damage 13

AC 24 knocks the poor guy down to hitting only on a nat. 20.

FWIW, I don't consider PA a worthy feat before at least level 2, so you can add more than +1.
My current group is debating the worthiness of PA at higher levels, as our 13th level fighter is getting beat up by monsters with ACs above 30. Perhaps he needs to sit back and let the warmage handle those, eh?

[Peregrine]

Finally loaded for me. I'm using Firefox, by the way.

One problem I see here is that it isn't taking every factor into account. For example, your total attack bonus. A 14th level fighter with 10 strength and dex has the same attack bonus as a 9th level fighter with a 20 strength (they've got other problems too, of course, since they clearly have no magic items to boost them, but that's their own problem). However, the 14th level fighter not only can power attack for more, he has iterative attacks to take into consideration. And you can't just put in 9 for the 9th level fighter, because his chance to hit is better than that, which would skew the results for when he should power attack.

To be truly useful, your BAB calculator needs a way to incorporate both iterative attacks and higher attack bonuses. This (http://www.greatplayground.org/tools/cookiepowerAttack) is currently my favorite power attack calculator, since it allows you to simply set your attack routine. This is especially useful if you have, say, haste, which grants another attack at your highest BAB. It has its problems (can't interweave different kinds of attacks), but it's generally pretty good.

As a matter of fact, it does take attack bonus and AC into account -- by effectively ignoring them both and skipping straight to attack rolls. No matter how high your attack bonus, you'll never hit on worse than a 2 or roll higher than a 20. To compare two characters with a difference of x in their attack bonuses, just compare the cells x columns apart. (Say, a fighter with Weapon Focus and one without. Weapon Focus is actually pretty effective. Weapon Focus alone beats Improved Critical alone in every case I've examined so far. Of course, they're even better together...)

I was working on a way to show iterative attacks -- click the cell for your main attack, and it will highlight successive attacks appropriate to your BAB -- but it was getting late. It's pretty easy to do though. Just move five columns to the right for each successive attack. Add up the figures. Add particular cells multiple times if you get multiple attacks at that attack bonus (flurry, Rapid Shot, TWF).

Edit: Incidentally, that is a nice power attack calculator you linked to. But mine more grew out of my calculations of comparative effectiveness, which is why you get a whole table: compare changes in PA and roll to hit (i.e. changes in attack bonus and AC) at a glance. That calculator only gives values for possible power attacks, corresponding to the green section of a single column in my table. (But conveniently, its figures do match mine. :smallsmile: Run it at its default values -- AC 20, attack bonus +6 -- and it gives you the same results as column 14 of my table for the same weapon. Hooray for independent confirmation of results!)

[Miles Invictus]

Umm, not quite. An L1 fighter with 16 Str has +1 BAB, +3 for Str in melee, so he hits AC 20 on a dr of 16+ (or 25%). Also, the average of a d6 is 3.5, so 2d6+4 is an average of 11 damage, and 2d6+6 is average 13.

vs. AC 20, the same guy has
no PA: 25% to hit, avg. damage 11.
with PA: 20% to hit, avg. damage 13

AC 24 knocks the poor guy down to hitting only on a nat. 20.

FWIW, I don't consider PA a worthy feat before at least level 2, so you can add more than +1.
My current group is debating the worthiness of PA at higher levels, as our 13th level fighter is getting beat up by monsters with ACs above 30. Perhaps he needs to sit back and let the warmage handle those, eh?

Dammit. You know what I was getting at, needing a natural 20 to hit with Power Attack versus needing a 19 to hit without it. I'll go back and correct it.

That's beside the point, though...I wanted to show that optimizing Power Attack can get complicated enough to make a table worthwhile.

[Piccamo]

My current group is debating the worthiness of PA at higher levels, as our 13th level fighter is getting beat up by monsters with ACs above 30. Perhaps he needs to sit back and let the warmage handle those, eh?

Has he looked at the feat Shock Trooper? How about Leap Attack?

[Peregrine]

You know, I knew something didn't seem right with my calculator. I finally figured out what. It doesn't go far enough to the left.

Now, I thought, you can't ever hit on a 1, no matter how high your attack bonus, so I don't need the 1 column. But I forgot something: The column numbers are the values needed before power attack. The actual rolls to hit increase by 1 for each row you go down (basically, add the row number to the column number to get the roll to hit).

This means that the table needs to go 18 columns to the left to be complete. This is where things like true strike come in, allowing you to power attack for your full BAB and still hit.

(Of course, another 18 columns won't fit very well, but I don't actually need them... I could just make all cells in each column be the same to-hit roll. Have you noticed that cells where you need a natural 20 to hit -- in the orange zone, if you have a 19-20 weapon -- all have the same value on each row? It's because they could just be collapsed into the one column. This would make the table hard to use, though: no longer could you just run a finger down the column to find the appropriate power attack amount. You'd have to run diagonally.)

So, yeah. If anyone's interested, the calculator will see corrections and enhancements, when I've got time.

PS Changed the thread title, so that this doesn't look like (or become) just a general discussion about optimising power attack.

[Peregrine]

And done. Rather than make it compact but hard to use, I rotated it left. Now each row is a different roll to hit without power attack, and the power attack values go by column. (Actual to-hit roll needed is the sum of the numbers in the row and column headers.)

Green cells, as before, are valid attack values, grey ones are invalid because you can't power attack that high. Red is still the optimum, pink is what you could achieve with a higher BAB. An orange cell is still an attack that cuts into your threat range (i.e. some attacks that would be threats actually miss), and so effectively reduces your threat range. New to this revised table: white cells. These are the cells where it appears you could hit on a roll of 1 or worse (i.e. with to-hit rolls that are so low that you only miss on a 1), or only hit on better than a 20 (but a natural 20 always hits). Effectively, some or all of your to-hit bonus has become irrelevant -- you'll note that, as you'd expect, a big power attack is indicated in each case.

And I've had a feat idea...