(Math) Power Attack is almost never worth it.


Classes


7 people marked this as a favorite.

Preamble: People complain that Power Attack is locked to the Fighter class, and suggest that everyone should get it. I think the real complaint is that Power Attack is almost NEVER a worthy option to take during combat, and I will set out to show it with mathematics.

Average Damage (AD) and Expected Damage (ED): Let's get some definitions out of the way to make the analysis easier to read.

  • Average Damage is the average damage you would get from rolling damage. E.g. the AD of 1d12+5 is 6.5 + 5 = 11.5

  • Expected Damage is the actual damage you can expect from an attack, factoring in accuracy. Looks simple right? Just take your Hit Rate and multiply it with your AD. But that's where Crit Rate comes into play. The formula for ED is actually:

  • Hit Rate * AD + Crit Rate * 2 * AD.

  • If you hit an enemy's AC on a 10, you have a 55% accuracy. Your Hit Rate is 50% and your Crit Rate is 5%.

  • ED = 0.50 * AD + 0.05 * 2 * AD = (0.50 + 0.10) * AD = 0.60 * AD

Opportunity Cost: To understand why Power Attack is bad, we need to look at the opportunity cost of using it. Power Attack costs 2 actions to make a single Strike, in its place we could have made a second Strike at -5 to attack.

In order for Power Attack to be worth it, its ED MUST be greater than the ED of our second Strike.

Assumptions: We'll make some assumptions for this exercise. They will try to be favourable towards Power Attack, when possible:

  • 1. We are using a d12 Weapon. Power Attack is normally the feat choice for 2H fighters and a higher damage dice means its ED is also higher.

  • 2. We assume a 55% accuracy for now. We'll examine other accuracy levels later.

  • 3. We assume the PCs are getting magic weapons at the appropriate level (1 below the item's level).

The nitty gritty: Ready to see why Power Attack is not worth it? Let's take a look.

At Level 1, Power Attack adds 1d12 to our damage, or 0.60 * 6.5 = 3.9 Expected Damage (see above for how we got to the equation).

If we made a second Strike instead, it would be at 30% accuracy, and its damage roll is 1d12+4, for an AD of 10.5. Its ED is:

0.25 * 10.5 + 0.5 * 2 * 10.5 = 0.35 * 10.5 = 3.675

At level 1, we are expected to deal 0.225 more damage with Power Attack. That's a very slim advantage. Looks like it could easily be quashed if, say, we increase the damage dice of our weapon.

Level 3 is where we obtain our first magic weapon (or our Wizard friend could cast Magic Weapon on us), and that's when Power Attack starts becoming worse than just attacking again.

Power Attack's ED stays the same at 3.9, but our second Strike is now dealing 2d12+4, for an ED of 0.35 * 17 = 5.95 damage.

Do we catch up at Level 10, when Power Attack is +2d12 damage? Let's see:

Power Attack: 0.60 * 13 = 7.8

Our Strike now deals 3d12+5 (+2 Weapon, 20 STR), for an AD of 24.5 and an ED of 0.35 * 24.5 = 8.575.

Nope! Still worse, and it doesn't get better from here on out.

But what if our accuracy is higher? Wouldn't Power Attack crit more often?

An excellent question, but the results won't change. At 60% and higher accuracy, we start to crit more often due to the new rules.

60% accuracy means hitting on a 9, so a 19 or 20 is a crit, i.e. our crit rate has become 10%. What's the formula for ED now?

Power Attack ED = 0.50 * AD + 0.10 * 2AD = 0.70 * AD

Our second Strike also has increased its ED, but by less because the Strike's crit rate did not go up. The formula is:

2nd Strike ED = 0.30 * AD + 0.05 * 2AD = 0.40 * AD

As we can see, with each +1 to attack, Power Attack's ED goes up by 10% and 2nd Strike's ED goes up by 5%. Will this actually help Power Attack? Let's compare these 2 values at level 10.

Power Attack ED increase = 0.10 * 13 = 1.3

2nd Strike ED increase = 0.05 * 24.5 = 1.225

While Power Attack improves very slightly with bonuses to attack, it would take a +10 attack bonus to bridge the gap, and that's just not possible to obtain.

Conclusion: Using Power Attack is ALWAYS worse than just attacking twice, and this is true in all cases except at the very beginning of the game (and that's only without the spell Magic Weapon).

Power Attack is in desperate need of a buff to make it a feat worth considering. Double Slice is just pure benefit, no matter the level, yet its competition is a lame horse.

Suggestion: Power Attack's damage dice progression needs to mirror the damage dice increase from Potency Runes, or stay only 1 dice behind at higher levels. To this end, I suggest that Power Attack gives 1 extra die at lvl 1, which increases by 1 extra die at levels 3, 7, 11, 15, 19.

This will give an expected damage increase of 0.225/1.85/3.125/4.75/6.025/7.3 assuming 55% accuracy, not entirely out of line with the damage boost from Barbarian Rage.


1 person marked this as a favorite.

You are ignoring a huge benefit of Power Attack by omitting from your analysis the third action to attack.


Someone already crunched the numbers with the same conclusion. It’s nice to see it done again to highlight the problem. It is worse once you get your first magic weapon.


GM OfAnything wrote:
You are ignoring a huge benefit of Power Attack by omitting from your analysis the third action to attack.

What benefit is there? Power Attack counts as 2 attacks for Multiple Attack Penalty, so that third attack doesn’t gain any advantage compared to someone just swinging 3 times


1 person marked this as a favorite.

Power attack should just double the amount of damage as per doubling rules. This would make it exactly equivalent to double slice if using 1d12 weapon compared to double 1d6 weapon, but slighly less damaging if using 1d8 (1h) weapon, balanced by the free hand.


Dekalinder wrote:
Power attack should just double the amount of damage as per doubling rules. This would make it exactly equivalent to double slice if using 1d12 weapon compared to double 1d6 weapon, but slighly less damaging if using 1d8 (1h) weapon, balanced by the free hand.

Power attack to just double damage? Sounds interesting. Is it too good at that point? really its getting rid of the -5 for a second attack and you can apply DR only once versus it. Have to check the math it might be too good that way. Also would it do x4 on a crit or x3?

Oh hey what if it just doubled dice? So if your potency rune makes you do 3d12 it would add 3d12 (presumably 6d12 at level 10 on?)


I think doubling might be a bit too good. But scaling higher than it currently does would certainly be beneficial.


After checking my math and comparing with Double Slice, I believe even just doubling he damage dice would be too good.

I still think PA should scale, but it should only scale to a maxmum of 5 additional dice. The level progression could look like 1, 3, 7, 11, 15 to match up with when you get better magic weapons.


how about +1 die every 5 so 1-5 +1 die 6-10 +2 etc?


Pramxnim wrote:

After checking my math and comparing with Double Slice, I believe even just doubling he damage dice would be too good.

I would like to see that. Doubling the damage means basically nothing more than getting +5 to your secondary attack, with the added bonus of applying only once resistance but with the additional penalty that, given the normal doubling rules, a crit would only increase your damage by 50%. It is better than attacking twice? It should damn be, it's a feat whose only purpose is exactly that.

Grand Lodge

Pramxnim wrote:


The nitty gritty: Ready to see why Power Attack is not worth it? Let's take a look.

What about when the enemy has any amount of resistance to your attacks?

What about when the enemy is dangerous to attack?

What about when you do a normal strike first and your options are power attack as 2nd and third action or normal attack twice more?


1 person marked this as a favorite.

Power attack should give a circumstance bonus to hit. The Martail classes in general don’t have any way to increase to hit. Currently the average chance to hit most creatures your level is around 40-60%. If power attack increased to hit, then you would be trading an attack/action for a better chance to actually land a hit plus an increased chance to crit.


1 person marked this as a favorite.

What about resistances as that was where I really liked power attack in 1e and felt not fun and really weak to say play a 2 weapon fighting character against something with DR in 1e. I have not played a fighter yet but have got to use double slice but unfortanetly had the wrong type of weapons out and didn't really want to take two actions to draw new ones double slice felt really cool to use.


Dekalinder wrote:
Pramxnim wrote:

After checking my math and comparing with Double Slice, I believe even just doubling he damage dice would be too good.

I would like to see that. Doubling the damage means basically nothing more than getting +5 to your secondary attack, with the added bonus of applying only once resistance but with the additional penalty that, given the normal doubling rules, a crit would only increase your damage by 50%. It is better than attacking twice? It should damn be, it's a feat whose only purpose is exactly that.

By doubling the damage do you mean a 3d12+5 Strike becomes a 6d12+10 hit? Yes, that is indeed too much damage when compared to a similar option like Double Slice. Since there are no rules about doubling damage twice like in PF1 (because the only thing that doubles damage is a critical hit), under that option, a crit would do 12d12+20, or simply too much.

Even without crits:

The ED of 6d12+10 is 0.6 * 49 = 29.4

If you’re using Double Slice, you’re limited to d8 and d6 weapons, since 1H weapons max out at d8, and agile weapons max at d6.

The ED of 3d8 + 5 + 3d6 + 5 is 0.6 * (13.5 + 10.5 + 10) = 20.4

So if you doubled the damage of an attack when Power Attacking, you’re expected to deal 9 more damage than a person using Double Slice, a comparable option. That’s just too big a difference, especially since the average numbers are gonna look very different as well.

AD of 6d12+10 is 49 while AD of Douvle Slice is only 34.

Power Attack should be a competitive option, not eclipse other viable fighting styles. Therefore, simply doubling damage is too much.

What about damage resistance?

Overcoming DR by combing 2 attacks’ damage into 1 is one of the main features of Power Attack, but it can’t be the only thing the feat has going for it. Otherwise it’ll be a very niche ability that will only be used when fighting enemies with resistance to the PC’s attacks.

TWF also has a way of overcoming DR in Double Slice, and that ability is just straight up better than taking 2 consecutive attacks. Why can’t 2H Fighters enjoy the same benefit as their counterparts?

EDIT: Here are some ED of Power Attack, with different additional dice added, at level 20. For comparison:

Double Slice ED = .6 * (6d8 + 6d6 + 14) = 37.2

2 attacks with d12 = .95 * (6d12 + 7) = 43.7

Power Attack ED:

2 extra dice = .6 * (8d12+ 7) = 35.4

3 extra dice = .6 * (9d12 + 7) = 39.3

4 extra dice = .6 * (10d12 + 7) = 43.2

For each extra dice, we add 3.9 ED. Power Attack needs to add at least 4 extra dice to be a viable option at level 20 compared to just attacking twice with a d12 weapon.


Pramxnim wrote:
Since there are no rules about doubling damage twice like in PF1 (because the only thing that doubles damage is a critical hit), under that option, a crit would do 12d12+20, or simply too much.

Yes there is. Page 299.

Quote:

Multiplying

When more than one effect would multiply the same
number, you don’t multiply more than once. Instead, you
combine all the multipliers into a single multiplier, with
each multiple after the first adding 1 less than its value. For
instance, if one ability doubled the duration of one of your
spells and another one doubled the duration of the same
spell, you would triple the duration, not quadruple it.


pojo2000 wrote:
Power attack should give a circumstance bonus to hit. The Martail classes in general don’t have any way to increase to hit. Currently the average chance to hit most creatures your level is around 40-60%. If power attack increased to hit, then you would be trading an attack/action for a better chance to actually land a hit plus an increased chance to crit.

This is because of the new +10 crit rule. Adding a plus to your hit is like weapon focus and improved critical at the same time. Hence no weapon focus feat, a simple feat,yet gone.

Feats also rarely add much damage due to the magic weapon factor (increasing weapon cage dice instead of +1 to damage)

These two factors make martial feat design very tricky.


My conclusion by comparing it to Double Slice is that any and all combat tactics which tax an action that otherwise could be spent attacking needs to include at least a +3 bonus on attack rolls to better the odds of landing a single crit, compared to a double.

I used a similar, if not the same formula.

I'm happy we get the same results.


Kerobelis wrote:
pojo2000 wrote:
Power attack should give a circumstance bonus to hit. The Martail classes in general don’t have any way to increase to hit. Currently the average chance to hit most creatures your level is around 40-60%. If power attack increased to hit, then you would be trading an attack/action for a better chance to actually land a hit plus an increased chance to crit.

This is because of the new +10 crit rule. Adding a plus to your hit is like weapon focus and improved critical at the same time. Hence no weapon focus feat, a simple feat,yet gone.

Feats also rarely add much damage due to the magic weapon factor (increasing weapon cage dice instead of +1 to damage)

These two factors make martial feat design very tricky.

They really don't, you just have to use new math to figure it out compared to PF1.

The issue with the comparisons to PF1 with respect to the new crit system is that your crit chance most of the time for what's intended to be a sufficient build (+4 ability modifier to hit/damage) is typically only ever going to get you around 10-15% crit chance by looking at the actual AC numbers in the Bestiary we have.

Since crits always double, they must be compared to just making two or more attacks instead, and when your odds to crit on a primary are 15%, then your chance to land a hit on a secondary attack are only 10-15% worse than landing a regular hit.

Using the OP example, if I have a 55% chance to hit on a primary, and a 15% chance to crit on it, then on my secondary I'll have 40-45% chance to hit still, and betting on 45% chance to land a second hit is way better than betting on 15% chance for my primary attack to be a crit on its own.

Thus the math says it's always better to count on multiple attacks with respect to hits anyway. Any time you have to lose out on an attack to enhance a primary attack, a bonus is needed to make up for what you lose in simply not using that feat or ability, especially if the plan is to make sure everyone has to buy a bucket of dice to enjoy this edition of the game.

Grand Lodge

Pramxnim wrote:

What about when the enemy is dangerous to attack?

What about when you do a normal strike first and your options are power attack as 2nd and third action or normal attack twice more?


1 person marked this as a favorite.
David Silver - Ponyfinder wrote:
Pramxnim wrote:

What about when the enemy is dangerous to attack?

What about when you do a normal strike first and your options are power attack as 2nd and third action or normal attack twice more?

Power attack has the [open] trait and thus must be used as a primary attack, forcing any and all other attacks you make to be tertiary.

Grand Lodge

(looks it up)

Point is conceded.

What about when the enemy is dangerous to attack?


David Silver - Ponyfinder wrote:

(looks it up)

Point is conceded.

What about when the enemy is dangerous to attack?

I need more context to answer this properly.

But my solution from doing math problems tells me that Power Attack should include a bonus to attack rolls, and improve your odds of landing a crit by somewhere between 10-15% thanks to the way the math distributes in order to balance its hypothetical damage weight, which might by virtue make the enemy less dangerous.

Grand Lodge

If a creature deals damage to you when you hit it, hitting it becomes less of a complete gain. If it is a significant strike-back, being able to gather your damage in less hits becomes more valuable.


2 people marked this as a favorite.
David Silver - Ponyfinder wrote:
If a creature deals damage to you when you hit it, hitting it becomes less of a complete gain. If it is a significant strike-back, being able to gather your damage in less hits becomes more valuable.

Find out how common this is and compare the statistical odds of running into it, at which levels you would, and power attacks potential damage value at those levels.


Pramxnim wrote:
Conclusion: Using Power Attack is ALWAYS worse than just attacking twice, and this is true in all cases except at the very beginning of the game (and that's only without the spell Magic Weapon).

Nice analysis.

They definitely need to redesign power attack.


David Silver - Ponyfinder wrote:
If a creature deals damage to you when you hit it, hitting it becomes less of a complete gain. If it is a significant strike-back, being able to gather your damage in less hits becomes more valuable.

Yeah. Otoh, class feats are supposed to be a major feature. So power attack seems like a quite expensive hedge if it only helps in case of retaliate and significant dr.


Pramxnim wrote:
At level 1, we are expected to deal 0.225 more damage with Power Attack. That's a very slim advantage. Looks like it could easily be quashed if, say, we increase the damage dice of our weapon.

While ED is a one way to compare options, it fails to account for one important aspect of combat: Killing power.

What Power attack gives (especially at lower level) is killing power. in order to accurately calculate the advantage of Power Attack, you'd need to include the probability a Power Attack + a second attack can outright kill the target compared to three strikes.

I just played Rose Street Revenge with Goblin Fighter using Power attack and d12 weapon did a total of 118 points of damage over four encounters. The paladin with a d8 and no Power Attack did 69. My archery Ranger and bear companion and d6 bow managed a whopping 23. In the last encounter, the Fighter critical hit the wounded BBEG with PA and did like 39 points and took it down.

Quote:
Conclusion: Using Power Attack is ALWAYS worse than just attacking twice, and this is true in all cases except at the very beginning of the game (and that's only without the spell Magic Weapon).

Of course it gets worse as the total damage increases. It's the same with any mechanic that simply adds a damage die. The Deadly property for bows becomes less beneficial as you add damage dice as well.

Community / Forums / Archive / Pathfinder / Playtests & Prerelease Discussions / Pathfinder Playtest / Player Rules / Classes / (Math) Power Attack is almost never worth it. All Messageboards

Want to post a reply? Sign in.
Recent threads in Classes