[Pathfinder] Gunslingers and Cannons

[Halae]

So I had an... interesting realization. Cannons are unwieldly and take multiple full round actions from an entire team to reload, but are very powerful. It's the reason gunslingers only use them if they're going after something like a fortified gate. However. We're looking at 6d6 per shot, which is honestly pretty good for actual weapon damage, but that's because, you know, it's a siege weapon

Here's the thing though. The Dead Shot deed allows you to pool all your iterative attacks into one singular massively powerful shot. a level 11 gunslinger with a haste buff and the rapid shot feat is looking at a single cannonball dealing 30d6+(x5 dex) damage. 40d6+(x5 dex) if it's a fiend's mouth cannon, and really, you want it to be if you're already dumping thousands of gold into this strategy. Plus, if you manage to critical with even one shot, you have a very good chance of quadrupling the damage from the whole shebang.

Oh, yes, and as a little extra gravy, the damage is dealt as one lump sum, so Damage Reduction? What's that?

Let's take a level 20 gunslinger for a moment. If he has rapid shot and a haste buff, he technically has seven iterative attacks. Assuming he's using this with a fiend's mouth cannon, that's 56d6 damage.

We can assume he has a minimum of a +10 dexterity bonus, which is quite frankly not all that large for the level it's at, which bumps the damage up to 56d6+70.

Assuming he's also taken Improved Critical (Cannon), he has a 10% chance per hit to make it a critical hit, which on such a weapon is x4 damage. If you do the math, that's a 52% chance to critical hit with this thing, so you're looking at 224d6+280 damage.

This sets the damage at 404 damage minimum. 1064 damage on average. 1624 at most.

Did I miss something? Does this actually work? Is there something preventing a cannon from being used with Dead Shot beyond, you know, not wanting to completely destroy what's most likely a high ranking fight?

[Elinvar]

Yes and no. I've actually been thinking of playing a gunslinger 1 / Fighter who is a siege expert, and carries around a small cannon.

The dead shot deed reads;
"At 7th level, as a full-round action, the gunslinger can take careful aim and pool all of her attack potential into a single, deadly shot. When she does this, she shoots the firearm at a single target, but makes as many attack rolls as she can, based on her base attack bonus. She makes the attack rolls in order from highest bonus to lowest, as if she were making a full attack. If any of the attack rolls hit the target, the gunslinger’s single attack is considered to have hit. For each additional successful attack roll beyond the first, the gunslinger increases the damage of the shot by the base damage dice of the firearm. For instance, if a 7th-level gunslinger firing a musket hits with both attacks, she does 2d12 points of damage with the shot, instead of 1d12 points of damage, before adding any damage modifiers. Precision damage and extra damage from weapon special abilities (such as flaming) are added with damage modifiers and are not increased by this deed. If one or more rolls are critical threats, she confirms the critical once using her highest base attack bonus –5. For each critical threat beyond the first, she reduces this penalty by 1 (to a maximum of 0). The gunslinger only misfires on a dead shot if all the attack rolls are misfires. She cannot perform this deed with a blunderbuss or other scatter weapon when attacking creatures in a cone. The gunslinger must spend 1 grit point to perform this deed."

Mechanically this changes a gunslingers hail of bullets to a single powerful shot in order to bypass DR and other similar things, kind of like vital strike, or the monk's equivalent which reads the same but for flurry of blows.
Its a really powerful skill, but not but is not too unbalanced unless you're fighting something which relies on DR exclusively.

The key here is the wording of "all her attack potential".
Because cannons take at least a move action to reload, and another one to aim, you can't actually use it on a cannon because you wouldn't be able to load seven shots into the cannon in your one turn and thus are breaking the action economy.

This is easily fixed though. If you have a gunnery team (they can be level 1 commoners, it doesn't matter) to reload the cannon for you, than you can make up enough actions to pull this off no problem. By default you'd need seven x your load time, which is three, so it could get a little cramped with 21 people huddling around a cannon.
You can narrow that down to 10 with Master siege engineer which lets them use move actions, and drop it down to seven if you give your guys (and yourself) a fantastic item called a swift runners shirt, which allows you to convert your swift action to a move action once a day.
This way you have 21 move actions to load your gun, one for yourself to let you aim it, and you still get have your own standard and move action to make your full attack and fire all those shots, so in this case you have the potential to fire seven times, and thus the deed works.

I think your math is off though because I believe the dex damage is not multiplied for this deed, (like vital strike) and when you crit on one "shot" only the damage associated with that "shot" is multiplied, not the total. As such, if you're using a fiend's mouth you're doing;

8d6 X 7 +10 = 206 on average, but seven shots at 10% crit chance each means 70% chane you're going to crit, so taking that into account;
8d6 X 4 = 112 average X 70% = 78.4
So you will in fact usually be dealing around 284 damage per hit.

I'd consider all this a legitimate way of keeping siege weapons threatening into higher levels, except that it works a bit too well: I looked it up and this is just enough to one hit a CR 17 Dragon.
Personally I'd let you get away with it once, since you need set up time and you've only got one shot. That said if this was going to be a regular thing I'd rule it so that any more people beyond the crew needed for the weapon do not help load it any faster. This would cap you at three shots, dealing a more modest 117.6 damage.
You could probably bypass this though by using more magic or mechanisms to reload the cannon faster though.

It might also be worth noting that although you have the potential to fire off seven shots with this build, you only actually fire once. This kind of puts you in a weird situation your crew only spends three move actions so no one needs to use their magic shirts because you only actually fire once the cannon once, and yet you need all of this or it doesn't work.
The above is why sometimes you just can't take rules as written seriously.

[Arutema]

Let's take a loot at the exact wording of the Dead Shot deed here.



Dead Shot (Ex): At 7th level, as a full-round action, the gunslinger can take careful aim and pool all of her attack potential into a single, deadly shot. When she does this, she shoots the firearm at a single target, but makes as many attack rolls as she can, based on her base attack bonus.

BAB only, no extra attack rolls from rapid shot or haste apply.



She makes the attack rolls in order from highest bonus to lowest, as if she were making a full attack. If any of the attack rolls hit the target, the gunslinger's single attack is considered to have hit. For each additional successful attack roll beyond the first, the gunslinger increases the damage of the shot by the base damage dice of the firearm. For instance, if a 7th-level gunslinger firing a musket hits with both attacks, she does 2d12 points of damage with the shot, instead of 1d12 points of damage, before adding any damage modifiers. Precision damage and extra damage from weapon special abilities (such as flaming) are added with damage modifiers and are not increased by this deed.

It says nothing about adding your Dex modifier from gun training multiple times, so you don't, only the cannon's admittedly high base damage dice.



If one or more rolls are critical threats, she confirms the critical once using her highest base attack bonus –5. For each critical threat beyond the first, she reduces this penalty by 1 (to a maximum of 0). The gunslinger only misfires on a dead shot if all the attack rolls are misfires. She cannot perform this deed with a blunderbuss or other scatter weapon when attacking creatures in a cone. The gunslinger must spend 1 grit point to perform this deed.


So for a regular cannon, your cap would be 30d6+dex modifier at BAB 16. I was throwing out 29d6 per round as a 13th-level evocation-focused sorcerer. Spoilered for the curious:

Base CL 13
Varisian Tattoo for +1 CL on evocation
Voidfrost robe for +1 CL on cold spells.
Cast lightning bolt for 14d6 as a standard action, then cold ice strike as a swift for another 15d6.


The monstrous crit potential is certainly there, but you're still lagging behind the casters on average rolls.

[Erik Vale]

Hmm... Ok, it becomes almost feasable now. When I look at it, I normally see the reload time, and go 'I'm using that in combat how?'

Also, how are you carrying it around? Given sizes I've found the only way to carry seige engines to be a Devil's Crux or large carts. Cart's are blocked by doorways, Devil's Cruxs on the other hand take several rounds to open [despite being stupid if you no the combo], and being in a small room means you've wasted a lot of cash.

Or you waste even more money on bags of holding, with the same problem as far as small rooms go.

Of course, the idea of a man suddenly pulling out a loaded cannon and blowing you away with it is awesome.

[Abrasis Mindlef]

Dead Shot at BAB 16 with Improved Critical(Fiend's mouth cannon)...

8d6 base; Dead Shot -> 32d6...

19-20/x4 crit chance; 10% chance to threaten a critical per attack roll, and you have 4 attack rolls...

= 34.39% chance of a critical threat if my math is correct;

Critical Dead Shot: 56d6 weapon damage; +[enhancement, Dexterity, deadly aim...]x4

[Halae]

Hate to put a damper on the fun, guys, but this thread was posted (and got no responses) back in August 2013. It's been dead long enough for all the flesh to have rotted off.

[Haruki-kun]

The Winged Mod: Indeed. I'm closing this thread now.