The relevant rules here are:
Critical Hits
When you make an attack roll and get a natural 20 (the d20 shows 20), you hit regardless of your target's Armor Class, and you have scored a threat. The hit might be a critical hit (or "crit"). To find out if it's a critical hit, you immediately make a critical roll'€"another attack roll with all the same modifiers as the attack roll you just made. If the critical roll also results in a hit against the target's AC, your original hit is a critical hit. (The critical roll just needs to hit to give you a crit. It doesn't need to come up 20 again.) If the critical roll is a miss, then your hit is just a regular hit.
A critical hit means that you roll your damage more than once, with all your usual bonuses, and add the rolls together. Unless otherwise specified, the threat range for a critical hit on an attack roll is 20, and the multiplier is Ã--2.
Exception: Extra damage dice over and above a weapon's normal damage is not multiplied when you score a critical hit.
Increased Threat Range
Sometimes your threat range is greater than 20. That is, you can score a threat on a lower number. In such cases, a roll of lower than 20 is not an automatic hit. Any attack roll that doesn't result in a hit is not a threat.
Increased Critical Multiplier
Some weapons deal better than double damage on a critical hit.
Spells and Critical Hits
A spell that requires an attack roll can score a critical hit. A spell attack that requires no attack roll cannot score a critical hit.
Multiplying
Sometimes a rule makes you multiply a number or a die roll. As long as you're applying a single multiplier, multiply the number normally. When two or more multipliers apply to any abstract value (such as a modifier or a die roll), however, combine them into a single multiple, with each extra multiple adding 1 less than its value to the first multiple. Thus, a double (Ã--2) and a double (Ã--2) applied to the same number results in a triple (Ã--3, because 2 + 1 = 3).
When applying multipliers to real-world values (such as weight or distance), normal rules of math apply instead. A creature whose size doubles (thus multiplying its weight by 8) and then is turned to stone (which would multiply its weight by a factor of roughly 3) now weighs about 24 times normal, not 10 times normal. Similarly, a blinded creature attempting to negotiate difficult terrain would count each square as 4 squares (doubling the cost twice, for a total multiplier of Ã--4), rather than as 3 squares (adding 100% twice).
Multiplying Damage
Sometimes you multiply damage by some factor, such as on a critical hit. Roll the damage (with all modifiers) multiple times and total the results. Note: When you multiply damage more than once, each multiplier works off the original, unmultiplied damage.
Exception: Extra damage dice over and above a weapon's normal damage are never multiplied.
Power Attack [General]
Prerequisite
Str 13.
Benefit
On your action, before making attack rolls for a round, you may choose to subtract a number from all melee attack rolls and add the same number to all melee damage rolls. This number may not exceed your base attack bonus. The penalty on attacks and bonus on damage apply until your next turn.
Special
If you attack with a two-handed weapon, or with a one-handed weapon wielded in two hands, instead add twice the number subtracted from your attack rolls. You can't add the bonus from Power Attack to the damage dealt with a light weapon (except with unarmed strikes or natural weapon attacks), even though the penalty on attack rolls still applies. (Normally, you treat a double weapon as a one-handed weapon and a light weapon. If you choose to use a double weapon like a two-handed weapon, attacking with only one end of it in a round, you treat it as a two-handed weapon.)
A fighter may select Power Attack as one of his fighter bonus feats.
Code: Select all
So, for this example I'm going to deal with a great axe, which has crit, has +4 strength, and -5 power attack, and is being wielded two handed.
So the damage code is as follows
(1d12+6(str)+(5)x2)x3
Now here is where the rules interpretation comes in, I did the following:
3d12+(6)x3+(5)x2x3
3d12+18+(5)x4
3d12+18+20
3d12+38
Now the alternative way is thus:
(1d12+6+10)x3
(1d12+16)x3
3d12+48
Anyway, I'd be interested to hear other opinions on the matter. I am certain that if a charging lance crits, all damage x2x3 then it is all damage x4. But whether you distribute the multiplier (as I did) is a little unclear, though my algebra makes me think you do.
Also, I think 2handed power attack could be quite game breaking without. (Especially when you factor int hings like Combat Brute and PCs with increased crit multiplier).