Edit: Check out the sequel, too.
Firearms have an uneasy place in medieval fantasy and for arguably good reason. The advent of the cannon had a deleterious effect upon many mainstays of the genre, from castles to plate armor. Also, gunpowder’s mere presence in a setting often implies a degree of change that it seems many authors dislike. OSR settings often assume an almost timeless and stubbornly static world where major innovations rarely change the world and if they do so, it is usually by way of causing a calamity and turning civilization backwards for a time.
Excuses vary for fantasy gun control, but they typically take two forms.
Removal, where gunpowder is outlawed, held in contempt, or physically impossible.
Ignorance, where the secrets of black powder were merely never uncovered, or more uncommonly and perhaps implausibly never put to military use.
Providing an alternative to gunpowder doesn’t seem to be so popular, for some reason. Perhaps it defeats the point? Gunpowder is an inconvenience to an author the same way that smartphones have become one. A lot of potential stories dependent upon an information arbitrage are ruined by the omnipresent connectivity of a modern phone.
Also, I’d note that are specific problems with the usage of gunpowder in tabletop games that aren’t often covered or understood by GMs or players. Black powder is unwieldy. It wets easily, it’s a pain to handle, black powder produces a lot of smoke, and an arquebus (and its close descendants) are notoriously hard to handle to say nothing of the reload time. None of these things are easily emulated by game systems, although I have seen drafts that treat wheellock and flintlock firearms as one-and-done items that can’t be reloaded in a close skirmish.
I don’t intend to provide a “solution” to an author who wants guns gone. Instead, I want to propose a fun alternative - one that I’ve enjoyed playing with in my own campaigns.
The Girardoni Air Rifle
Invented in 1779 AD and for some time utilized by the Holy Roman Empire, the Girardoni Air Rifle1 was not so much an improvement upon the rifles at the time as it was an alternative to them. Although fussier and more fragile than their black powder cousins, the air rifle had some curious advantages over it.
Being entirely powered by air, the air rifle had no powder to be wetted by rain, and could be used more effectively under poor conditions.
Because the rifle could hold dozens of leaden balls at a time, and because the reload mechanism required no mucking about with manual powder loading, the Girardoni rifle was the first true repeating rifle and also extremely fast to fire. We’re talking fast enough to be useful repeatedly on the time-scale that RPG combat takes place at. You don’t even have to bend the fiction that much.
The weapon had no muzzle flash or smoke clouds, allowing the operator’s view to remain clear and unobstructed despite the incredible rate of fire.
Without a muzzle flash or smoke clouds, and with a remarkably quiet report, the rifle was well-suited for snipers who didn’t want to give their position away. In fact, this characteristic gave the rifle a sort of black reputation as an assassin’s weapon.
This was further enhanced by the fact that the weapon could be fired repeatedly while lying prone; rather than require that the operator stand up to reload, he could simply pull a spring-loaded chamber bar to slip a new musket ball inside.
Unfortunately, the weapon also had several drawbacks that prevented its immediate and enthusiastic adoption:
The brass air reservoirs the Girardoni rifle used were difficult and expensive to make at the time, with what metallurgy was available. Making a pressurized metal container that could hold a great deal of air in an 18th century blacksmith is no mean feat.
As a compounding and related problem, the reservoirs were fragile. Smashing your rifle’s butt too hard against a rock might crack it open, rendering it worthless - not a great feature in an outdoors environment.
Refilling a pressurized container with air might be easy today, but at the time all you had to work with was muscle power. The cart-powered pumps and smaller hand-pumps could take an hour or more to refill a single reservoir, and one reservoir only managed around 30 shots at lethal pressures. And reservoirs, as covered above, weren’t cheap enough to be manufactured easily.
Finally, the things required skills to operate that most soldiers couldn’t be easily trained to possess. Someone who knew how to operate a black powder rifle was lacking several skills needed to handle an air rifle.
But you know what? The way the air rifle operated sounds awfully similar to how I’ve seen black powder rifles handled in games already. Nobody bothers with powder smoke, do they? And the drawbacks don’t mean anything to player characters who are already skilled, cut-above-the-rest professionals. So here’s the fantasy air rifle.
The Fantastic Air Rifle
In Taiao, I call them Girardian2 weapons, after their supposed inventor. They're a new invention, exotic anywhere except for the warring states where they were invented, and coming into prominent roles in warfare. They come in two forms.
Air Pistol: 1-handed, Weight equal to a dagger, Damage 1d6! blunt3, Range ~235’
Air Rifle: 2-handed, Weight equal to a sword, Damage 2d4! blunt, Range ~275’
I don’t include prices since everyone’s is wildly different (and I vary them even within a campaign), but the air rifle is generally about the same price as a longbow, or four times as much as a sword. Both can only be found in large port cities or other places where exotic curiosities are found.
All Girardian weapons follow these rules:
Air guns require a replaceable air canister, attached to the weapon as the stock of the rifle for air rifles, and attached to/part of the grip for air pistols. These canisters are fragile, and if violently impacted, dropped, or otherwise abused will rupture (I break 1d4 fragile items in a pack every time one gets dropped).
Air canisters can store up to 30 shots’ worth of air before recharging.
Air guns have a remarkably quiet report and no muzzle flash. They are not silent, but it is extremely hard to locate a shooter outdoors. They may be fired and reloaded while prone.
Refilling an empty air canister takes 1 hour.
Unlike most OSR firearms, Girardian guns require no reload step and may be fired as frequently as the user can attack.
Air canisters are considered ammunition and are sold individually for 33% of a pistol’s price (or 25% of a rifle’s price). A maintenance pack with air pump and cleaning tools is sold separately for a modest fee, weighs as much as the rifle, and is required for recharging the canisters. Lead slugs are about four times pricier than arrows and will put a bigger dent in a new PC’s wallet, too.
It should also be noted for anyone doing some system conversion that blunt damage in Taiao ignores damage reduction, so these things punch through most of plate armor’s protection and a bit of mail too. It doesn’t ignore Defense/AC increases though, so armor is still worth something. Air guns aren’t as powerful as gunpowder, after all.
1d4 Magical Air Gun Mods
There is no way there aren’t magicians who have seen a gun and wondered how to improve it.
Wind-magic reservoir that refills itself. Probably also reinforced so that it won’t rupture as soon as it’s whacked against a rock. Or maybe it isn’t?
The firing chamber imparts an elemental effect (fire, lightning, necrotic poison) upon the leaden ball as it leaves the gun.
Multiple additional firing chambers have been bolted together and modulated by a magical wind-directing structure, creating a double- or triple-barrel gun with correspondingly increased damage and muzzle retort.
The gun literally fires blasts of wind, which are harmless but automatically knock victims within 10’ prone.
Quick Edit: Neat Video
If you’re interested in the full details on the real-life gun, here’s a good complete explanation. You’ll also get a look at how wrong my rules regarding pump time were - the real air canisters only take about 20 minutes to refill by hand. Whoops. But an hour rounds easier in the dungeon for time-keeping, and your players don’t have to know either way.
Girardoni Air Rifle - Wikipedia
In honor of the unrelated Rene Girard, who I have a certain interest in.
The exclamation marks exploding dice; if you roll the maximum number, add a new die and roll again. 1d6! can become 3d6 if you get two 6s in a row. It averages out to something like 4.2 and 6.5 average damage for the pistol and rifle respectively.