Bayonet + Gunshot combo

[Chilxius]

My players are about to encounter The Empire for the first time, and I've decided to include gunpowder weapons as part of The Empire's arsenal. Rank-and-file will use rifles, important NPCs will often use revolvers, and cannons might come into play for the "they have a cave troll" moments. Partly this is to ramp up the threat and differentiate The Empire, but it's also just cool, and I'm hoping a player will choose to learn to use them.

I'm rolling up a rival for one of my players. He's a dagger man (Invisible Blade) whose primary weapon is the bayonet on his revolver (using rules from C Scoundrel p109). I'm imagining something like the Pritchard (https://collections.royalarmouries.org/first-world-war/type/rac-narrative-138). One of my players is a Final Fantasy fan and I know he'll appreciate a gunblade, which this essentially is.

My question is this: Once my NPC scores a hit with the knife, he should be able to discharge a bullet into the target. How much of his action economy should that cost? Would that be an additional attack, or an automatic bonus (assuming rounds are chambered)? And, how hard should the gun's attack roll be? If the knife is actually in the target, hitting could be assumed as a given. Maybe it should require a feat to use properly.

I'm fine with this guy being fearsome, and with having some "woah, he can do WHAT!?" moments. But I would like it to be fair, especially since my player will eventually be wilding this thing.

[GeoffWatson]

Just because you've reduced their hit points with the knife, doesn't mean they're impaled.

Maybe give a bonus to hit with the gun attack? Ignore the "firing in melee" penalty?

[Beni-Kujaku]

There is a feat called Snap Kick that allows you to make a kick attack after each attack (whether it's a regular attack or a full attack), not costing an action. You could easily refluff it to firing a bullet in melee, and requiring Exotic Weapon Proficiency (gunblade) instead of Improved Unarmed Strike.

[Maat Mons]

I feel like benefit of your ranged weapon also being a melee weapon is just that you can attack an adjacent foe without provoking an attack of opportunity, or a distant foe without moving.

I seem to remember a hammer with a spike that exploded out of it for extra damage on a hit, but then needed to be reloaded. Maybe you could use whatever rules that thing uses.

[Forrestfire]

There is actually a pair of weapons that does basically that in Dragon Magazine #321, the spear pistol and shield pistol. In that issue, these are priced as +300gp modifications to go into a spear or shield and, when you successfully hit, discharges the pistol for +1d8 damage (and applying any magical effects on the gun, letting you "double dip" on magical enhancements). These only work once before needing to be reloaded (a standard or move action depending on version; in practice it's a move action with the breachloading attachment) may not be exactly what's being looked for, as the PC in question is using a gun that fires rather than a gun that shoots a single shot and then needs to be reloaded. The same issue has a "gunblade" one (the hilt pistol) that is treated as two-weapon fighting (with all the penalties, and provoking AoOs in melee), rather than auto-hitting. Personally, I would probably combine the two if running it in my own games.

Below is a homebrew variant adapted from these existing rules options:






Light Exotic Weapons

Cost
Damage (M)

Critical

Range Increment
Weight
Type


Gun-Dagger (melee)

1,000gp

1d4

19–20/×2

—

5 lb.

Piercing or Slashing



Gun-Dagger (ranged)

—

1d8

×3

30 ft.

—

Piercing




Gun-Dagger: This custom-made knife can be used as a dagger by those proficient in simple weapons, but using it to its full potential requires Exotic Weapon Proficiency (firearms) or the Knife-to-Gunfight Style feat (see below). Someone properly proficient in this weapon can, 1/round as a free action on a successful hit in melee, discharge the firearm component into the target, adding 1d8 piercing damage and spending one round of ammunition. On a critical hit with the dagger, add 3d8 piercing damage instead (but do not otherwise multiple this damage for the crit).

Alternatively, the weapon can be fired normally, using the listed weapon statistics when making ranged attacks, even mixing melee and ranged attacks in the same round if the wielder uses the Two-Weapon Fighting rules. The ranged and melee components of the weapon are enhanced separately, and do not otherwise overlap for the purposes of benefits or effects when making attacks (even when discharging a shot with a melee attack, you do not use your ranged weapon enhancements).

A gun-dagger can hold six rounds at a time, and is reloaded as a move action (or a free action if the wielder has the Rapid Reload feat).


Knife-to-Gunfight Style
You've dedicated yourself to proving an old adage false.
Prerequisites: Dex 15
Benefit: You are proficient with the gun-dagger, and can fight with it as if you also had the Two-Weapon Fighting feat. If you do, your ranged attacks don't provoke attacks of opportunity from any creature you've hit in melee with the weapon in the same round.
Special: This feat counts as Two-Weapon Fighting for the purposes of meeting prerequisites and requirements. A fighter may select this feat as a bonus feat.


This uses a hybrid of the spear/shield pistol rules and the hilt pistol rules, as well as merging a specialized proficiency feat with Two-Weapon Fighting (to let it be more conveniently added to a build). I dispensed of the "you can apply both your magical enhancements from melee and ranged components" double-dipping for my version to make it a little less weird to build around, opting to just go for a straightforward damage boost and making it easier to TWF in melee with.

If your game's guns have different numbers of rounds, then you can modify the amount in the listing above; I just went with six because it's iconic and because it's a good number for mechanics (it allows someone to go for two rounds worth of full attacks at mid- and mid-high levels, between Two-Weapon Fighting, Improved Two-Weapon Fighting, and a 1/round melee damage boost for three shots each round; in theory Rapid Reload is nice at that point but not required).

Thoughts?

[Prime32]

The Parthian rapier from Ravenloft Player's Handbook includes a single-shot pistol which you can fire as a free action after hitting with the rapier; you still need to make an attack roll, but the target is denied their Dex bonus to AC. You need both Exotic Weapon Proficiency (firearms) and Exotic Weapon Proficiency (Parthian rapier) to use it to full effect.


I seem to remember a hammer with a spike that exploded out of it for extra damage on a hit, but then needed to be reloaded. Maybe you could use whatever rules that thing uses.
The war spikard from Magic of Eberron (as well as the spear spikard). It doesn't seem very practical even if you've already got the EWP and Rapid Reload feats for some reason. Can't make ranged attacks, only 1d8 base damage despite needing two hands to wield, and the damage boost for firing it is implemented in a weird way (not multiplied on critical hits, helps less than normal with overcoming DR, and consumes bolts without applying their properties).

[Chilxius]

I'm using the Modern Weapon section from the DMG, which suggests revolvers deal 2d8 damage and hold six rounds. That's a lot for a normal weapon, but in the hands of my NPC the dagger deals 1d4+12+4d6 sneak (which Invisible Blades have NO trouble activating), whereas the gun is only 2d8+2. It's more of a cool factor, really. I think I'll go with this, as a rule specific to this campaign:

A successful crit with the bayonet allows you to attack with the revolver as a free action at a -2 penalty.

That makes logical sense (it's likely impaled after a crit) and should be fair for my player once he eventually gets the weapon. It will make crits with this thing devastating, but this is a major antagonist. It would probably be best from a game balance stance to make this a feat, but that would put my players two feats away from using it (Exotic Weapon Prof and Bayonet Blast) and I don't want to show them a cool thing and then tell them they aren't allowed to eat dessert until they eat 6 levels' worth of vegetables.

After thinking about this, I could see Gun Kata [TACTICAL] or Bullet and Blade [STYLE] being cool feats with a lot of world building built in. But that's just my restless DM brain.

Thanks to everyone who commented.