Trex damage with Power attack

[Atalius]

Just had a question was wondering if I could get some clarity on the power attack feat. Lets say I have a level 7 Trex animal companion with the power attack feat. Two questions, one how much damage does his bite attack do (assuming a STR of 24)? and second question how much does he do under Animal Growth? Please show how you calculated his damage so I can see how it works, thank you.

[Garbage-Tier Waifu]

If the bite is his only natural attack, it does 1.5X his strength modifier. This bonus is also applied to the power attack bonus.

If the Trex has any other natural attacks, it's only 1x Strength and Power Attack bonus.

This is explained in the Natural Attack section of the rules.

Natural Attacks wrote:

If a creature has only one natural attack, it is always made using the creature's full base attack bonus and adds 1-1/2 the creature's Strength bonus on damage rolls. This increase does not apply if the creature has multiple attacks but only takes one. If a creature has only one type of attack, but has multiple attacks per round, that attack is treated as a primary attack, regardless of its type.

Power Attack explains in the feat description that natural attacks made 1.5x strength modifier apply this bonus to it's damage as well.

Power Attack wrote:

This bonus to damage is increased by half (+50%) if you are making an attack with a two-handed weapon, a one handed weapon using two hands, or a primary natural weapon that adds 1-1/2 times your Strength modifier on damage rolls.

So, as for damage which took me a while to get since the d20pfsrd is having problems...

I'm going to assume the Trex has some kind of enhancement to Strength from animal companion progression since once it increases to large, that goes up to +8. So 22, then 24 after it's increase.

Our Rex has 24 Strength, and under Animal Growth it becomes Gargantuan. Size increases to weapon damage get kinda messy at this point but I believe it's bite attack increases to 4d6.

A Trex at this point also has 32 Strength. A level 7 animal companion has an attack bonus of +4.

Edit: So, yeah, Powerful Bite also grants x2 Strength on damage with your bite. Totally missed that part!

So our Trex has a bite attack bonus of:
1d20+4(BAB)+11(Strength)-3(Size)-2(Power Attack)

And a damage bonus of:
4d6+22(Strengthx2)+6(Power Attack+50%) <- RAW interpretation
4d6+22(Strengthx2)+9(Power Attackx2) <- Consensus interpretation

Ask your DM for their opinion.

[Firebug]

The "consensus" is that Power Attack on a critter with Powerful Bite uses the 3:1 increment instead of the 2:1 increment.

So 2d6 + 14 (2x strength) + 6 (3:1 PA at BAB +4)
Animal Growth increases the critter one size category, specifically its natural attacks go up one stage and it gains +8 size bonus to strength.
2d6-> 2d8 per the monster universal rules, and a strength of 32.
2d8 + 22 (2x strength) + 6 (3:1 PA at BAB +4)

[Garbage-Tier Waifu]

Oh it has powerful bite! okay, yeah, I definitely agree with Firebug, but that is largely an interpretation rather than RAW explanation, since Power Attack only goes up to 1.5x in the text. We'd need another example of a creature using power attack with Powerful bite or similar ability to prove that.

Sorry! I'll edit my post to fix the numbers.

[Firebug]

I put "consensus" in quotes because if you look closely at Power Attack:

Power Attack wrote:

Benefit: You can choose to take a –1 penalty on all melee attack rolls and combat maneuver checks to gain a +2 bonus on all melee damage rolls. This bonus to damage is increased by half (+50%) if you are making an attack with a two-handed weapon, a one handed weapon using two hands, or a primary natural weapon that adds 1-1/2 times your Strength modifier on damage rolls. This bonus to damage is halved (–50%) if you are making an attack with an off-hand weapon or secondary natural weapon. When your base attack bonus reaches +4, and every 4 points thereafter, the penalty increases by –1 and the bonus to damage increases by +2. You must choose to use this feat before making an attack roll, and its effects last until your next turn. The bonus damage does not apply to touch attacks or effects that do not deal hit point damage.

The 3:1 increment is only for Primary Natural Attacks (which the Tyrannosaurus' bite is) "that adds 1-1/2 times your Strength modifier on damage rolls" (which it doesn't, it adds 2x not 1.5x). So you "should" be using the 2:1 increment.

We're talking 1 damage difference every +4 BAB, but last time I brought this up on the forums, there was a lot of anger.

Interestingly, since you have an ability that specifically makes its bite use 2x strength, if you add additional natural attacks somehow it maintains the 2x strength.

[Garbage-Tier Waifu]

Oh, geez, I thought this was going the other way.

You're totally right that is silly. Okay, this is a lot deeper than it appears. Lol that's kinda silly.

[Firebug]

Were you assuming Improved Natural Attack to get up to 4d6?

[Garbage-Tier Waifu]

Animal growth increases size by two steps. So I'm pretty sure that's 4d6 from a baseline of 2d6.

[Firebug]

No it doesn't?

Animal Growth wrote:

The target animal grows to twice its normal size and eight times its normal weight. This alteration changes the animal's size category to the next largest, grants it a +8 size bonus to Strength and a +4 size bonus to Constitution (and thus an extra 2 hit points per HD), and imposes a –2 size penalty to Dexterity.

[Garbage-Tier Waifu]

Oh, geez, I horrendously misread that. My bad.

[Chess Pwn]

Requirements in pathfinder work that having more means you have enough. Power attack says str 13, but having more than that is okay, it's the minimum needed. So 1.5 str is also the minimum needed for the increased damage

[Atalius]

Firebug wrote:

The "consensus" is that Power Attack on a critter with Powerful Bite uses the 3:1 increment instead of the 2:1 increment.

So 2d6 + 14 (2x strength) + 6 (3:1 PA at BAB +4)
Animal Growth increases the critter one size category, specifically its natural attacks go up one stage and it gains +8 size bonus to strength.
2d6-> 2d8 per the monster universal rules, and a strength of 32.
2d8 + 22 (2x strength) + 6 (3:1 PA at BAB +4)

Hmm wouldn't 2D6 go to 3D6?

[nicholas storm]

2d6 goes to 3d6

[Firebug]

Per the FAQ, yes it goes to 3d6.

Earlier I had said 'per the monster universal rules', because I knew where they were and didn't feel like tracking down the specific FAQ on my phone.

[Errant_Epoch]

Meanwhile I'm sitting here wondering what a trex is before I'm like "oh a T-Rex" lol