The Conundrum

One of the most annoying parts of Dungeons and Dragons, is that when it comes to applying rules for powerful weapons, it becomes difficult to manage them into a way that is fun, but also balanced.

If you make them feel powerful, as close to realism as possible where a shot to the chest is more often fatal, it is more often than not that to maintain this element, weapons feel overpowered, the fantasy is lost, and as we add in weapons that have a cycling rate of more than once per turn, this explodes into issues upon issues.

If we attempt to balance them, through use of something along the lines of damage reduction, or ballistic resistance, or shaped armour to hope to ricochet a shot in the style of T34 or Panther tanks sloped armour, we end up losing the simplicity of combat. Though sure, it's just one more stat to add, but now every item that has the potential to act in this way needs to be worked on and maintained for balance and it becomes a huge task for something that should have a much more elegant solution.

The Solution?

I don't profess to hold the answer to this issue, but for my world atleast, I believe I have a solution that is better than the years i've spent delving through decade old PDFs on Traveller20 and SciFi20, and even further obscure, to figure out a more elegant solution than adding damage reduction to armour, in a system that obvious wasn't designed for it. At one point I thought possibly flat footed could be the answer, but as we move to 5e we lose that system aswell.

Our tools in 5e are few, but simple, and elegant, based around ease of play and rapid resolution.

In relation to this solution, we have Damage Resistance (half damage), Damage Immunity, Advantage, Disadvantage, AC, Spells, and various Armour Modifiers. (Required strength, max dex etc)

And what we want, is something that we can scale, as if we only wanted muskets, a simple stronger but louder Crossbow could work.

The solution for me came when looking at an ability one of my Players used called Scorching Ray.

For reference:

Scorching Ray

You create three rays of fire and hurl them at Targets within range. You can hurl them at one target or several.

Make a ranged spell attack for each ray. On a hit, the target takes 2d6 fire damage.

At Higher Levels: When you cast this spell, using a spell slot of 3rd or higher, you create one additional ray for each slot above level 2.

Range. 120ft

Components. V S

Duration. Instantaneous

Casting Time. 1 action

Level. 2

School. Evocation

Classes. Sorcerer, Wizard

Spell Attack. Ranged

Damage. 2d6

Damage Type. Fire

Ammunition Balance

Now imagine a rifle from a SciFi universe with burst fire. Shooting 3 bolts on an aimed action, dealing 2d6 per each bolt that hits the target, sounds almost exactly like the spell, scorching ray, because it is. Dungeons and Dragons already has the mechanics we need, but instead of looking for them in our weapons that are designed to be as simple as possible, we need to look at our spells.

If we removed the spells from DND, the game would be completely different, it is balanced around the use of such things as, shooting lightning at people, crushing them with the mountains that surround them, freezing them to death with shards of ice, draining their life with necrotic damage, and yet when we use ranged weapons, we limit them to their traditional single damage with a reduction of mechanics.

If we separate Ammo, and Ranged weapons, we are able to balance the ammunition separately from the weapon, and we can give the ordinance fired properties that are already play tested and balanced at the correct levels of play. We have already Wands, Staffs, and Scrolls of spell craft, in effect we do the same for Guns, we can maintain the fantasy of a world of Guns, Swords, Bows and Spellcraft.

Ammunition Variety

In the modern and real world, there are any number of ammunition types, in even just the World War 2 video game War Thunder in it's Tank mode we have at least 6 different varieties.

Below is an example of the various rounds used in World War 2.

HE, a High Explosive shell, often used against soft targets that don't need to be penetrated to inflict maximum damage.

AP, an Armour Piercing shell, often a solid shot used against targets fired at maximum velocity to punch a hole through armour.

APCR, Armour Piercing Composite Rigid, is also a solid shot shell, but unlike traditional shaped rounds, they are rigid points with cores of super hardened metal to promote penetration.

APHE, Armour Piercing High Explosive, similar to an AP round, but with a core filled with explosives for maximum damage on penetration.

HEAT, High Explosive Anti Tank, on impact firing a hot jet of super heated metal that bores through practically anything, and so range becomes irrelevant as it is a chemical reaction on impact.

HESH, High Explosive Squash Head, this round does not penetrate, instead as it reaches the target it spreads over the surface of impact, a split second later it explodes, denting the metal, and fragmenting it on the other side filling the tank with shards of metal from it's own armour at lethal velocity.

These are just a few varieties showing that Ammunition can hold a multitude of forms and have a huge variety of applications.

The same also applies to Rifles, just a quick look at this list here on WikiPedia shows the huge variety of shells fired in just 7.62mm that are standardised.

The same also applies to Shotgun shells, you have Slugs, Buckshot, Birdshot, Rocksalt, Flechette, Explosive, Dragons Breath, the list goes on, along with varieties on these shells also.

We can use this to allow our players to have more customisation, and to balance the weapons that we'd like in our game, adding effects similar to what we have in spells to certain classes. Maybe you want to inscribe runes on your Bolt Action rifle Ammo that detonate on impact, calling lighting from the sky, maybe it should make the earth rise up in anger, but we could also do the same for Arrows, Bolts, Grenades.

Examples

The below is my world's version of a 8 magazine 12 gauge shotgun, featuring a field made solid slug, and a flechette round filled with scrap, or some sort of metal that fragments on ignition. In revisions likely the range will extend greatly for solid shot rounds, making the benefit over spells the range.

Strong-Arm of Langhyrst

Type: Ranged Weapon

Subtype: Heavy Ranged, Firearm

Features: Magazine 8, Pump Action, 18.5mm Shell, Failure 5, Critical Failure 2.

This weapon uses standardised 18.5mm shells and is equipped with an 8 shell capacity magazine.

After you have attacked once with this weapon, you may use it's pump action to fire again as a bonus action with disadvantage or lose half of your movement, this extra attack with a pump action also provokes an attack of opportunity if used in another creature's threat range unless a certain feat is taken.

You may reload the magazine by 2 rounds per standard action, or 4 if you spend both your standard and bonus action reloading.

You may load a shell into the breach manually as a bonus action instead.

18.5mm Shell, Shatter

Type: Ammunition

Subtype: 18.5mm Firearm Ammunition

Features: Collateral (20ft.+), Ranged (20/40)

Cost: 5gp each

The damage of this shell is determined by the range from the target.

0-5ft. 3d6 (same damage as burning hands)

6-15ft. 3d4

16-30ft. 3d2

31-40ft. 1d4

If the target is over 20ft away, creatures within 5ft of the target must succeed a Dexterity saving throw else take 1d4 damage on a failure.

18.5mm Shell, Armour Piercing

Type: Ammunition

Subtype: 18.5mm Firearm Ammunition

Features: Ranged (30/90), Armour Piercing 1

Cost: 5gp each

You gain +1 to attack when firing the Armour Piercing 18.5mm shell.

Deals 3d4 damage on a hit. (same damage as Level 1 Magic Missile)

Pricing of Ammunition

Based on this table and this table we can see the progression of money per fight per XP if we compare it to an encounter generator such as this one.

So balancing the price of Ammunition should be based on how much you reward them. But i'd say for example these example shells are based roughly off level 1 spells, and so from 2 to 3 one might have 280gp after fighting say 18 orcs. And so should probably be priced around 5-10GP for each highquality round.

If you allow, let them make their own rounds that are lower quality, but scale with their level, that they can have a maximum amount on them at a time, or degrade each day. Treat them like or less than spells, remembering that a Cantrip does about 1d10-1d12 damage and will be the main filler for the user that often doesn't have heavy armour until about level 3-5 when they have the option for more regular spell casting.

Economy

The below is a bit long and rambly but explains how I feel one should tailor the setting or situation for the Campaign.

With finding balance based on spell strength and effects, we have to keep in mind that those that dedicate their lives to spell craft have limited use per day, and should still have the ability to feel strong than just surrogates of more complex mechanics and limitations.

As such, you need to implement a reason for limited ammunition or power to that ammunition. If you take an AK-47, from current day status and place it in a fantasy setting, it won't work, especially if your players cant separate the idea of the fantasy to break down buildings with our hands as a barbarian, and so it is important to maintain that when it comes to using firearms as well, a man isn't going to die from a single bullet if he can also be hit by 30 arrows and still walk around fine.. The key is to maintain the fantasy, your setting needs to explain how weapons come to pass that function in this way, why doesn't everyone use them, and if everyone does, then likely your setting has become more modern with a twist of fantasy, than fantasy with a twist of modern.

Design your guns in homage to what inspires you within the rules of your setting, in example, in the Tarred Skies setting there is a resource known as Etherflora, that is left behind by the swarm. This Etherflora is taken, refined, and turned into eventually something that can be used as a propellant, among other things. As such, perhaps the shells that are used in this world are very different, perhaps they are large, the size of Shotgun shells, perhaps the propellant inside of them is volatile and rapidly deteriorates outside of certain conditions, such as refrigeration, and so large weapons with a high cycling rate might require a certain backpack that is heavy, sluggish, and very expensive to run and maintain to keep your ammunition cool, this backpack then plugs into something that looks close to an AK-47, but perhaps looks slightly different, and as it fires your face lights up in the cool green glow that explodes from the end of the rifle.

Turn economy is also very important for this, if a person can shoot 10 times in a single attack, then move and get into cover with something of the strength of a Bow for each attack, then the combat will be off balance. Use the fantasy, maybe all of your guns work in like plasma rifles shooting pure energy doing low damage but are easy to shoot, maybe they shoot with a high recoil that user needs to spend time and movement to shoot accurately, just as one would need to spend time standing from prone. Perhaps a spell is modified like shield that reduces damage from ballistic weapons of that type, perhaps armours are designed specifically against it than all amours having a DR stat for it, rather than having to add a damage reduction from everything of that source, similar to how some undead are resistant to necrotic, perhaps the shells always do necrotic damage for that purpose and so many creatures are resistant to it and so you must need another type of ammunition.

The player has learned that throwing lighting, stabbing, slicing, and near decapitating someone in a game like DnD won't result in instant death, it is a fantasy of superpowers very unlike our own mortality, in this example in the Fairy Tail Anime, they take many hits but still stand, many Fairy Tail fights are similar to how a Dungeons and Dragons fight would go, taking hit points multiple times but not outright dying in a good and balanced fight until one side falls to 0. Work on the fantasy and amplify it, you could also take a more reality based point of view, many Thriller / Horror scifi shows rely on an enemy that isn't easily killed, such as Starship Troopers, Star Gate and Aliens. But having weapons in a setting where everyone is just a normal real life guy isn't going to work in the style of DnD where we level up as adventurers, where we go against enemies with hundreds of health points. We gain

In the world of Aerdeskol, in the Setting of Tarred Skies, the swarm features Horse Sized insects, similar to those on Starship Troopers, the weapons are designed to kill Insects, and so are more cumbersome, have larger ammunition and therefore are often more expensive, and so many people use swords and simple kinetic weapons. When infrastructure is limited, you don't have the ease of mining in the best places, and moving it to the best place to refine, and then moving to the best place to create the product, and then moving to the buyer, and so replacement parts and resources become limited, in the show Revolution, one of the villains has a Desert Eagle pistol, a menacing .50 caliber handgun. The people that he works for control the guns, control the ammunition. A blacksmith could work out how to make a sword that doesn't dull on the first strike, a fletcher could figure out how to make a bow from wood and sinew, but a gunsmith without the lathe, without the metal stock, without the ease of flow of ammunition, would be at a premium. This fight scene from Revolution shows how a weapon that an outside town could afford to make and maintain would be at a disadvantage to a well versed swordsman.

So to reiterate, apply the fantasy rules, set a rule of what the laws of your firearms and the production line are, it doesn't matter how high technology any civilisation is, if they don't have the resources to use their technology, and fairly limit the power of your weapons in turn economy.