Perfect Strike - Mighty Strike combo?

[draconswan]

I'm going to be starting the Wrath of the Righteous campaign shortly, and in building out a Heritor Knight character, I found a potential combo that I'm not 100% sure about.

Using the Mighty Strike ability from the Heritor Knight means I can use the Vital Strike feat chain on any attack action made as part of a standard action.

The Perfect Strike Mythic Abilty says:
You can expend one use of mythic power as a standard action to deliver a perfect strike. A perfect strike attack is made using your full base attack bonus. If the attack hits, it deals double the normal amount of damage, and this damage bypasses all damage reduction and hardness. If the perfect strike is a critical hit, increase the critical multiplier for the attack by 1 (so a x2 weapon deals x3 damage). Damage that isn't multiplied on a critical hit isn't multiplied on a perfect strike. Perfect strike can be used in conjunction with any champion's strike if you expend uses of mythic power for each ability separately.

I read this as an attack action made as a part of the standard action to activate the ability. If this is true, then how would the damage work out?

Sample:
STR bonus of +4

Say I'm using a longsword:
1d8 + 4

Perfect Strike would double the damage (which I read as doubling the dice and STR bonuses) leading to 2d8 + 8

Vital Strike would turn the base damage to:
2d8 + 4
Improved Vital Strike would instead be:
3d8 + 4
Greater Vital Strike would instead be:
4d8 + 4

If Perfect Strike does instead stack with Vital Strike (and it's successors), what would that damage be?
4d8+8/6d8+8/8d8+8?

[blahpers]

5d8+8/6d8+8/7d8+8.

[draconswan]

@blahpers can you explain that progression please?

[blahpers]

Through lousy mental math. Lemme try that again.

Vital Strike/Improved Vital Strike/Greater Vital Strike doubles/triples/quadruples your base weapon dice. Perfect Strike doubles both your base weapon dice and any additional damage from Strength, etc. General multiplying rule requires multipliers to be combined additively rather than multiplied:

Core Rulebook wrote:

Multiplying

When you are asked to apply more than one multiplier to a roll, the multipliers are not multiplied by one another. Instead, you combine them into a single multiplier, with each extra multiple adding 1 less than its value to the first multiple. For example, if you are asked to apply a ×2 multiplier twice, the result would be ×3, not ×4.

So base weapon damage would be multiplied by a total of 3/4/5 and additional damage would be doubled. This comes out to

3d8+8/4d8+8/5d8+8

Sorry for the confusion!

Edit: Technically, the Vital Strike feats don't multiply but rather have you roll two/three/four times and add the results, so YMMV on this one. If you don't treat it as a multiplier, then you end up with 4d8+8/6d8+8/8d8+8 as you mentioned above.

[Isabelle Lee]

Vital Strike is, indeed, not a multiplier, and so doesn't run afoul of the stacking multipliers rule quoted above. However:

Perfect Strike wrote:

Damage that isn't multiplied on a critical hit isn't multiplied on a perfect strike.

Since Vital Strike damage isn't multiplied on a critical hit, it isn't multiplied by Perfect Strike either. Thus, the damage sequence would be (1d8+4)x2, or x3 for a critical hit, plus 1d8 per tier of Vital Strike.

If you possess Vital Strike (Mythic) - and let's all be honest, you will - the damage sequence becomes (1d8+4 plus 1d8 per tier of Vital Strike)x2, or x3 on a critical hit.

Hopefully my back-of-envelope math here is all correct... it's very early in the morning for me. Good luck with the heritor knight! ^_^

[draconswan]

Thanks All! Yes, this character will take the Mythic Vital Strike. The character I'm test-building would be a Marshal army leader, with a combo of Vital Strike crits and Intimidation/Dazzling Display. He took Divine Fighting Technique (Iomedae). I see Dazzling Display as a Move action, Vital Strike against a flat-footed enemy (due to Dazzling Display and a feat that improves it), all the damage to their face. Should be a fun and interesting build.

[blahpers]

Isabelle Lee wrote:

Vital Strike is, indeed, not a multiplier, and so doesn't run afoul of the stacking multipliers rule quoted above. However:

Perfect Strike wrote:

Damage that isn't multiplied on a critical hit isn't multiplied on a perfect strike.

Since Vital Strike damage isn't multiplied on a critical hit, it isn't multiplied by Perfect Strike either. Thus, the damage sequence would be (1d8+4)x2, or x3 for a critical hit, plus 1d8 per tier of Vital Strike.

If you possess Vital Strike (Mythic) - and let's all be honest, you will - the damage sequence becomes (1d8+4 plus 1d8 per tier of Vital Strike)x2, or x3 on a critical hit.

Hopefully my back-of-envelope math here is all correct... it's very early in the morning for me. Good luck with the heritor knight! ^_^

Thanks as always!