[3.5e] Exact Value of Power Attack

[ericgrau]

Hello, my goal here is to find not only the best power attack modifier to use but also how much extra damage you're really getting. i.e., you gain damage per hit, but you lose some damage from misses. Most people don't understand damage per round very well, so I decided the most user-friendly format would be effective-damage-per hit. Basically I add the extra PA damage, then subtract the damage lost due to misses (spread out among your hits). That's the simple explanation, anyway.

So here it is (assumes two-handed fighting):
Effective Boost to Average Damage

PA Modifiier:	2	(-2 AB, +4 damage)

Avg. Chance to
Hit without 
Power Attack	Average Damage without Power Attack		
		10	15	20	25	30	35	40
10%		-3.00	-5.50	-8.00	-10.50	-13.00	-15.50	-18.00
20%		-3.00	-5.50	-8.00	-10.50	-13.00	-15.50	-18.00
30%		-0.67	-2.33	-4.00	-5.67	-7.33	-9.00	-10.67
40%		0.50	-0.75	-2.00	-3.25	-4.50	-5.75	-7.00
50%		1.20	0.20	-0.80	-1.80	-2.80	-3.80	-4.80
60%		1.67	0.83	0.00	-0.83	-1.67	-2.50	-3.33
70%		2.00	1.29	0.57	-0.14	-0.86	-1.57	-2.29
80%		2.25	1.63	1.00	0.37	-0.25	-0.87	-1.50
90%		2.44	1.89	1.33	0.78	0.22	-0.33	-0.89
							

PA Modifiier:	4						
							
Avg. Chance to
Hit without 
Power Attack	Average Damage without Power Attack		
		10	15	20	25	30	35	40
10%		-1.00	-3.50	-6.00	-8.50	-11.00	-13.50	-16.00
20%		-5.50	-9.25	-13.00	-16.75	-20.50	-24.25	-28.00
30%		-4.00	-7.33	-10.67	-14.00	-17.33	-20.67	-24.00
40%		-1.00	-3.50	-6.00	-8.50	-11.00	-13.50	-16.00
50%		0.80	-1.20	-3.20	-5.20	-7.20	-9.20	-11.20
60%		2.00	0.33	-1.33	-3.00	-4.67	-6.33	-8.00
70%		2.86	1.43	0.00	-1.43	-2.86	-4.29	-5.71
80%		3.50	2.25	1.00	-0.25	-1.50	-2.75	-4.00
90%		4.00	2.89	1.78	0.67	-0.44	-1.56	-2.67
							

PA Modifiier:	6						
							
Avg. Chance to
Hit without 
Power Attack	Average Damage without Power Attack		
		10	15	20	25	30	35	40
10%		1.00	-1.50	-4.00	-6.50	-9.00	-11.50	-14.00
20%		-4.50	-8.25	-12.00	-15.75	-19.50	-23.25	-27.00
30%		-6.33	-10.50	-14.67	-18.83	-23.00	-27.17	-31.33
40%		-4.50	-8.25	-12.00	-15.75	-19.50	-23.25	-27.00
50%		-1.20	-4.20	-7.20	-10.20	-13.20	-16.20	-19.20
60%		1.00	-1.50	-4.00	-6.50	-9.00	-11.50	-14.00
70%		2.57	0.43	-1.71	-3.86	-6.00	-8.14	-10.29
80%		3.75	1.88	0.00	-1.88	-3.75	-5.63	-7.50
90%		4.67	3.00	1.33	-0.33	-2.00	-3.67	-5.33

PA Modifiier:	8
(All entries lower than PA for 6)

Naturally this assumes your chance of hitting is between 10% and 90%. If you hit on anything except a nat 1, even after power attacking, simply add that PA damage for free and don't subtract anything (no damage lost to misses).

Hopefully this will be of some help to people who play in games where their attacks have a chance of missing and they're deciding between, say, power attack and weapon specialization. It should also help show the value of +1 AB (if you're thinking of weapon focus, perhaps). For example, when you're dealing 30 damage, have an 80% chance of hitting, and you PA for +2, you gain +4 damage but lose 4.25 (net -0.25 shown on table). Thus +2 AB is worth 4.25 damage to that player, or +1 AB is worth about +2 damage.

If you have a way to always hit like wraithstrike or true strike or a very high AB, you of course take advantage of your free power attack. These tables are only for when your attacks have a chance of missing. Though I know some people play in games where that doesn't happen...

sword-and-board and leap-attack: For SABers (who don't switch to THF when PAing), double your "average damage without power attack" before using the table. Then divide the result you find on the table by 2. For leap attackers (assuming two-handed for 4x), multiply your "average damage without power attack" by 1/2 before using the table. Then multiply the result you find on the table by 2. (EDIT: fixed leap attack).

Full Attacks: Use your average chance of hitting for all attacks. This will usually be lower than your chance of hitting on single attacks. So the PA mod you choose for charging in may be different than the one you use on your full attack.

TWFers: This is complicated and PA isn't worth it for most TWFers anyway, so I won't get into this.

[UglyPanda]

Nice work but a few people have beaten you to the punch when it comes to calculating power attack.
http://direpress.bin.sh/tools/power.html

I feel that power attack is pretty much a required feat if you're a melee character past level 6, but that's just me. There are some exceptions, like characters who deal most of their damage through bonus dice.

[bosssmiley]

Goodman's Games "Warrior Power Gamer's Guide" looked at the Power Attack statistical analysis thing in exhaustive detail too.

IIRC the way to maximize average damage output/rnd was to only ever PA for either a -1, or for the absolute maximum penalty you could take.

[Frosty]

Leap Attack is actually 4x, not 3x, so it'seven better. But to be honest, if you're a fighter of some sort, find ways to do Power Attack without taking attakc penalties. It's the only way to do it and keep up in damage.

[Sstoopidtallkid]

Leap Attack is actually 4x, not 3x, so it'seven better. But to be honest, if you're a fighter of some sort, find ways to do Power Attack without taking attakc penalties. It's the only way to do it and keep up in damage.

Hence the joy of Shock Trooper. Especially if you have a way to gain a miss chance or two instead of AC.

[ericgrau]

Unlike existing power attack calculators, this table tells you not only the best PA mod to use but also how much your PA is helping. Honestly I put it together because I was tired of people telling every noob "OMG, you got to take power attack right away and never ever take the fighter tree." PA helps under various circumstances, but as you can see from the table it's not always the automatic thing to take. Unlike this table, a PA calculator might not show you that you're only averaging an extra +1 damage per hit.

I mean, I can average 13 damage at level 1, and it only goes up after that. Even then I'd be tempted to take weapon spec, weapon focus and, heck, dodge (+1 AC to you is -1 AB for the baddy!) instead and never touch PA over my entire adventuring career. Without automatic-hit uber-builds I'll get at most, what, 3 damage? But if I face a lot of gelatinous cubes or mooks or w/e then I'd want PA really bad. I mean if I could frequently give up 2 AB (or more) without lowering my chance to hit, that's 4 easy damage (or more). Or leap attack means I need 30 base damage to be in the same situation as above, and then I might want PA. Or etc.

So whether or not you take PA really depends and it's not the automatic thing to tell every new player. Especially those without 3 splatbooks, wraithstrike and leap attack.