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Flawed House Rule: 3.0 Power Attack

posted Friday, January 18th 2008 by Jonathan Drain
Game DesignThird Edition

Many DMs institute a set of “house rules”, custom game rules intended to enhance the game, which can occasionally go wrong. Previously I’ve discussed why double-rolling hit dice and “realistic” sneak attack are bad ideas. My topic today is Power Attack, where a DM I spoke to denies two-handed weapon users the double Power Attack damage that they gained in the 3.5 revision. Good change, or bad?

Lets take a sample character, Stush the Manticore Hunter. He’s a level 5 fighter, with a Strength of 18 and an attack bonus (including equipment) of +11. Stush deals 1d8+5 damage with a longsword and 2d6+7 with a greatsword. He’s also a big fan of Power Attack.

Stush fights a manticore, AC17, a 75% chance to hit. First, consider the longsword. Our hero deals an average of 7.125 damage per round, which raises to 7.5 if we Power Attack for 3, the optimal amount. With the greatsword our average per round is 10.5. Without the double damage, Power Attack actually lowers the average slightly, dropping to 9.5 with full Power Attack of 5. Including the double, however, we see a peak of 12.1 average damage at Power Attack 4.

The reason for the 3.5 double-handed Power Attack rule is that Power Attack isn’t simply free damage. When you increase your chance of missing altogether, you risk losing all of your damage. The result is that Power Attack actually becomes weaker when you use a two-handed weapon, because you’re throwing away more damage than normal. This is why the double is necessary, especially since two-handed weapon users are the ones who should be using Power Attack the most.

If you’d like to read more about damage, check out the article “Optimizing Power Attack” in the current issue of Kobold Quarterly.

Comments

  1. Philip Kendall

    January 18th, 2008

    From those numbers, the one-handed power attack increases damage by (7.5-7.125)/7.125 ~ 5%, whereas the two-handed increases damage by (12.1-10.5)/10.5 ~ 15%, so it does seem to be significantly more powerful for two-handed attacks as opposed to one-handed attacks. Whether that means you should increase the power of one-handed or decrease the power of two-handed (1.5x rather than 2x?) is left to be discussed.

  2. Jonathan Drain

    January 18th, 2008

    The damage increase is greater, but what you need to remember is that the cost is proportionally higher. Lets take an extreme example and say you deal 100 damage per hit. Taking a -1 attack penalty will increase your damage to 101, but at the cost of a 5% miss chance. That miss chance will cost you an average of 5%, or 5 damage. If you dealt 1,000 damage, a -1 attack penalty would earn you 1 point of damage and cost you 50.

    In other words, if you deal more regular damage, Power Attack’s damage bonus becomes proportionally weaker.

  3. Phased Weasel

    January 18th, 2008

    Good article.

  4. Philip Kendall

    January 18th, 2008

    I’m not disputing that 1x is underpowered for two-handed weapons, but that doesn’t mean that 2x is the right multipler to make it balanced either.

  5. Robert

    January 20th, 2008

    Power Attack can be quite unbalanced when a Sorcerer/Fighter takes it to use with True Strike, using a lance two handed from the back of a charging mount. Use up the entire True Strike bonus for +80 damage, available at relatively low levels.

  6. Matt

    January 20th, 2008

    Two things, one related and one (unfortunately) not related.

    The first… good statistical analysis of the problem. It looks appetizing to take the power attack with two-handed weapons, and yet isn’t. We’ve never run into any problems of it breaking a character in the least. First, it takes a full feat… what else could you take? Weapon Specialization, for example. That’ll give you guaranteed extra damage per hit, instead of having to gamble on it. Second, isn’t there a cap on Power Attack, in response to Robert’s reply? I may be mistaken. If not, that may be a consideration for house rules, to get around True Strike. And then, you get RP reasons… bigger swords/weapons may be less acceptable in “polite society”, don’t allow shields, and go with a certain style of fighting that might not appeal to everyone.

    The second thing, your e-mail’s not working, Jonathan. I tried e-mailing to d20@jonnydigital.com , and it sent it back to me with fatal errors. Might want to get it fixed or looked into, unless it’s just my e-mail that’s not going through. I’d had questions about Bones Dicebot and where to put code (and what code to insert) to accommodate NickServ identification, if I want to register the bot name with the server.

  7. Jonathan Drain

    January 20th, 2008

    You’re correct. It’s capped at your base attack, and requires Strength 13 to take the feat at all. Assuming your mage tries this, he’ll only be able to strike for 20 bonus damage at level 20, and that’s if he can hit in melee at a mage’s base attack with a -10 penalty (not likely).

    There are much better (and safer) ways at that level for a mage to deal significant damage: 20 damage is roughly the same thing as 3d6, and a 20th level mage can outclass that quite straightforwardly with his scorching ray.

  8. mike

    January 21st, 2008

    My biggest issue with Power Attack is not the two-handed weapon / 1.5 str for using two hands / 2x power attack damage…it is more with the continued chains that you can do. Two examples that immediately spring to mind is Leap Attack and Frenzied Berserker, both of which increase the power attack multiplier. And that’s before you even throw in the multipliers for lances, mounted combat, and spirited charge. In my experience, it quickly deteriorates into a swingfest – the berzerker has about a 50% chance of hitting, and whatever he’s attacking will be killed in a single blow. Ruins combat in my opinion.

  9. Jonathan Drain

    January 21st, 2008

    mike: Indeed, and there are some ridiculous combinations out there, and Power Attack is often a central part of those because it’s pure damage. Even one of the more basic charge build combinations can have a high level character striking for hundreds of damage.

  10. Robert

    January 22nd, 2008

    You know, I always read that wrong. I took it to mean that for my Bar1/Sor3/Ftr2 (or was it a higher level) that if I had a total of +15 to hit, I could take the +10 so long as the full BAB remained intact. Oh well.

  11. Spud

    February 21st, 2008

    Power attack allows for large damage outputs, yes, but unfortunately, it’s all fighters really have going for them. A well spec’d mage can shut down a battle in a single turn, without moving, while invisible, from several hundred feet away, against an opponent who has an arbitrary number of hit points (save or die spells). The fighter has no such ability.

  12. Luke

    April 3rd, 2008

    One thing people have to remember, is that the bonus for power attack to a two-hand weilder is to balance the damage outputs of dual wiedlers. I’ve experienced this difference myself, a well built dual weilder doesn’t outclass the double-hander in damage for one reason, the applications of power attack.

    For example

    My lv 12 ranger has a strength of 26 (18+2+6) and is using twin +2 Kukri (improved Critical for 25% crit chance) and weapon focus for a +1 to hit (multiple other feats but these are the basic ones applicable.) On a full attack action, he takes 6 attacks, at 19/19/14/14/9/9 to hit(21-2 for 2wpn fighting), each dealing 1d4+6 damage. (house ruled that light weapons don’t take the 1/2 strength penalty in the off-hand, one I believe not only just, but that simplifies combat math a bit) On a strong (slightly lucky) roller, this yields 2 critical hits for a full attack, meaning that, assuming he hits, his damage is as follows

    (1d4+10)x2+(1d4+10)+(1d4+10)x2+(1d4+10)+(1d4+10)+(1d4+10) (estimate 2.5 damage per d4)
    25+13+25+12+13+12= 100 damage

    Meanwhile, the lv 12 fighter has a strength of 26(18+2+6)-6, (with feats weapon focus, specialization, and greater version of each) and is using his +3 greatsword. Taking away power attack to an amount that equals the ranger’s attack bonus 25(12+8+3+2)-10 yields him an additional 20 points of damage per attack. (critical ratio is too low to calculate into estimated damage per round) 2d6+12+4+12

    (2d6+28)+(2d6+28)+(2d6+28) (estimate 3.5 per d6)
    35+35+35=105 damage for a full attack action.

    With straight, raw damage it comes out near even, without the application of additional feats for special power attack details or extra dice weapon propperties. Extra dice favor the dual-wielder, as they apply more times (further increasing the ratio of damage not affected by power attack.)

    Its my first public analasys of a dnd issue, it certainly wouldn’t bother me if someone were to email me their thoughts.

  13. KasraKhan

    July 19th, 2008

    I’m surprised dual-wielding wasn’t brought up sooner. In reality they are extensions of the same idea, though, sacrificing attack bonus for added power.

    I digress.

    I don’t understand DMs who wouldn’t allow double power attack damage on 2-handers, given the AC they sacrifice (my players and I are actually a fan of shields, especially magic ones), and as far as I’m aware, in 3.5 the limit on power attack is 5, not your base attack, and not unlimited.

    However, these calculations fail to take into account fighting an enemy altogether too strong or meat shields (or oozes) with lower AC than normal CR for PCs of that level. Granted, meat shields die quickly anyway, but sacking 5 attack for 10 damage rather than 5 is appealing regardless of how much health a meat shield might have (might change from two hits to one, causing a noticeable difference in enemy death speeds). Additionally, any enemy who’s AC is more than 19 above the PC’s BAB is simply more vulnerable to 2-handed power attack than a one handed one, if you play by auto-success on 20 rules variant (is it a variant? I’ve always played auto-succeeds and auto-fails).

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