How do YOU use Power Attack?

[Petrosian]

Second the notion, or third it...

as a rule of thumb do not use PA on FRA with iterative swings. its almost never worth it (bashing down an ice wall is an exception as is likely hitting helpless people or unattended objects.)

Even with single swings from standard attacks and charges, its gonna have to be an EASY hit to matter and the more your base damage is before PA the less likely PA will help.

Thats why you cannot take artoomis example as doing anything but showing you HOW TO DO THE MATH... his figures relied on a 15th level or so fighter doing 1d8 damage and that skewed his results. he did this to simplify the example i figure.

 

[Christian]

True, true. But Artoomis's example showed how to do the math ... which is much better than dismissing PA out of hand. There are circumstances, even on a full attack, where it's worthwile to move some points. It's possible to get a feel for it during the fight, but it's much better to do some figures in advance ...

 

[Shard O'Glase]

The thing is low AC opponents who even very likely strikes with your 2nd and 3rd attacks are very common. 20 ac is a high ac for most monsters in the monster manuel. Sure there are some exception monsters with acs of 30+, but the vast majority of them seem to be under 20 even high CR monsters they seem to survive through lots of hp. It is very possible to end up with even after a power attack a miss on the 1st two swings only on the roll of a one or 1-3ish. 12th level fighter, weapon focus, magic weapon, high str and quite frankly his +21/+16/+11 is low on the attack scale. My cleric who had power attack after buffs, was attacking at +23/+18. The fighter in that same group was attacking after he was buffed at a slightly higher level even. But heck even at his +21/+16/+11 if he put 3-4 points into power attack and against most monsters he only misses on a 1 with his 1st hit, and on maybe a 5 or less hits on the 2nd, and the 3rd hits with a 10 or less. The loss of 15-20% accuracy on the 2nd two hits is probably worth the damage boost.

 

[SpikeyFreak]

If you want to see how power attack affects damage at ceratin ACs, check out my damage calculator:

http://solo23.abac.com/spikeyfreak/Melee_Damage_Calculator.htm

--Power Attack FIEND Spikey

 

[kreynolds]

If you want to see how power attack affects damage at ceratin ACs, check out my damage calculator:

http://solo23.abac.com/spikeyfreak/Melee_Damage_Calculator.htm

--Power Attack FIEND Spikey

Spikey? You pimp that spreadsheet off worse than a San Fransican gigolo.

 

[the Jester]

Well, my ranger character uses power attack frequently... it's more useful for a two weapon fighter type since you have more attacks at your higher bonuses.

Another thing to factor in is your threat range, because that power attack doubles with a crit (or more for a x3 or x4 weapon.) So if your threat range is 17-20 and you're attacking four times the odds are fairly good that the 5-point power attack will give you +10 to one attack's damage in a given combat (not necessarily in a given round).

Just something to consider... anyone wanna crunch the numbers including threat range and crit multiplier?

 

[WaterRabbit]

Two words

Damage Reduction

It is useful to use power attack when your opponent has DR, then you are at least doing some damage.

 

[Jens]

I once calculated this with explanations, but now I can't find it so you only get the conclusion. It should be easy to remember:

To maximize expected damage, use Power Attack to equalize your average damage per hit and the number of sides on the d20 that will hit.

This also works with multiple attacks, just use the average number of sides on the d20 that will hit. Let's for example say that, without using PA, your 2 attacks will hit the target on rolls of 6+ (15 sides) and 11+ (10 sides), so that you will hit on an average of 12.5 sides if the d20. If your average damage is 8.5, you'll equalize the two by PA'ing by two points. This will increase your expected damage by 3.76% since (10.5*10.5)/(12.5*8.5) = 1.0376... Not a whole lot

Qualification: This is how to get the maximum *internal* solution without considering the limits. So if you have a really poor chance to hit, PA'ing fully may be better (running may be better yet, but that's a different matter).

Why? 1. Expected damage is proportional to average damage per hit and to the chance to hit. 2. The largest rectangle with a certain circumfrence is a square.

Atroomis' example: +21/+16/+11 vs. AC 20, on average doing 4.5 point of damage on a hit. Without PA, the average to hit number of sides is 17 (ignoring limits). (17-4.5)/2 = 6.25, or about 6. So he should PA by 6 points, exactly Atroomis' other calculation.

Crits: 'Normal' crits don't affect this once they're accounted as part of average damage per hit. For example, the average damage from a hit by a longsword counting crits is (4.5+S)*1.1 with S being the '+' bonus from strength etc. Special crits effects (butst weapons etc.) are more troublesome and will change things a little (you should PA a little less, I think).

 

[Christian]

Very nice 'rule of thumb' method, Jens. It gives a decent guess at the best bonus to use, and even if someone wants to calculate more precisely, it gives you a base range to look at.

It also makes it easier to see why PA is better when damage bonuses and/or Armor Classes are lower and when only a single attack is able to be made ...

 

[Petrosian]

Hmmm.. solving some formulas and making some test cases it seems to work like this...

H = sides on a d20 that hit. (variable from 1-19)
A = average amount of damage on a non-PA swing. (variable)

Amount pf PA shift to be applied to maximize the damage output is

(H-A)/2

So if you hit 17 times out of 20 and the average damage per hit normally is 13, use +2 for PA.

Probably there are some cases where the to hit for multiple attacks is so high that this shifts off slightly, but it seems to hold. Also in general round up. probably for multiswings use the average of the hit chances.