But be aware, guns do a lot more than make a loud boom. They’ll change your setting irrevocably, and that isn’t a bad thing. Settings that grow and change are better for it. Keep these things in mind when throwing muskets into your medieval fantasy setting.
1. Castles Become Purely Decorative
Before gunpowder, castles were the ultimate expression of power for a feudal lord. Tall stone walls kept enemies out and the lord’s wealth safe. Castles presented a conundrum to enemy armies. On the one hand, storming them was incredibly costly if not impossible. On the other hand, going around them meant leaving a well-armed enemy garrison at their backs. While siege engines did exist, catapults and trebuchets were inaccurate, hard to build, and difficult to transport.
Instead, most armies would try to starve a castle out. Well-stocked castles could hold out for years, often until reinforcements arrived or the enemy ran out of food themselves. But cannons changed that forever. Essentially long metal tubes, cannons were far easier to construct and move than pre-gunpowder artillery. They were also far more effective.
Tall stone walls proved no match for gunpowder-propelled shots. Suddenly, storming a castle wasn’t just feasible, it was downright easy. Even if the defenders had their own cannon, a castle’s massive walls were far larger targets than the scattered gun emplacements of an attacking army.
It didn’t take long before castles were little more than over-built homes for the nobility; their strategic value became a distant memory. New fortifications had shorter, thicker walls that were almost never made of stone.
How to Use This in Your Story
If your characters are nobles, they’ll need to deal with stubborn holdouts who insist the old ways are best. Despite the enemy’s shiny new cannon, the king is convinced his ancestral walls will hold. Naturally, they won’t.
Alternatively, your characters might be among the first to realize how useful cannons are. Perhaps their ragtag band of rebels is the only force in the country with access to gunpowder, making them a threat to the despotic queen despite their lack of numbers.
2. Plate Mail Rises, Then Declines
Shortly after cannons, your setting will see the rise of handheld firearms. At first these will just be scaled down versions of the original—literally hand cannons. Slowly, they’ll get more complicated, from matchlocks to wheel locks to flintlocks. While these weapons are inaccurate, and often dangerous to the user, they do have one obvious perk: they tear right through armor. Consequently, most soldiers stop wearing armor pretty quickly. Who wants to carry around boiled leather as a fashion statement?
The exception was plate mail–armor made up of overlapping metal plates. For quite some time, handheld firearms weren’t powerful enough to penetrate plate mail, except at extremely close range. Instead of falling out of style, plate mail became even more popular. Generals made every effort to equip their soldiers with plate. It was the only way to protect them from the devastation of gunpowder weapons.
Plate mail’s golden age did not last. More powerful guns meant the armor had to be thicker and heavier. As the flintlock musket came into common use, more powerful shots punched through even the thickest steel armor. Plate mail became an expensive relic, worn less and less as its protection waned.
How to Use This in Your Story
For one thing, you get to describe soldiers wearing plate mail and wielding matchlock muskets. This is the classic conquistador costume, though it rarely shows up in fiction. Most stories assume that guns haven’t been invented or that they’ve come to completely dominate the battlefield. Few look at the time in between.
Plot-wise, your story could focus around a band of firearm-equipped rebels struggling to invent a weapon powerful enough to overcome the plate armor of their enemies. The evil duke has all the money he needs to cover his soldiers in steel from head to toe. All the rebel leader has is her gunsmithing skill.
Or, you could flip the equation. Your characters witness the first time flintlocks are used against their country in battle. Their side is devastated. Their nation put beneath the boot of conquest. Their friends killed or maimed by weapons against which even the strongest armor is useless. What are they going to do about it?
3. Nobles Matter Less in War
For a long time, any army that took itself seriously needed a core of wealthy aristocrats. These second and third children of wealthy houses made war their business. In Europe, they were the heavily armored cavalry that broke the enemy’s formation with a mighty charge. In Japan, they were mounted samurai archers, trained to hit any target while at a full gallop.
Nobles were the only people who could afford the best tools of war. Maces, longbows, plate armor, horses–none of these paid for themselves. A peasant conscript was lucky to get a metal-tipped spear. Perhaps more importantly, nobles were the only ones with the leisure time to learn war. If peasants spent four hours a day practicing with swords, their crops would wither and they’d be ruined. Nobles had the luxury of long training sessions, and they used them to deadly effect.
But the gun changed everything. Since guns were relatively cheap to produce, entire armies could be equipped with these armor-destroying, cavalry-smashing death tubes. Being able to afford a sword and shield no longer carried much advantage. At the same time, guns were fairly easy to use. With a simple point and click interface, anyone could learn to shoot with a lot less training than what’s required for a sword or bow.
Before guns, monarchs needed support from their nobles to wage war. Powerful houses could oppose the war simply by keeping their scions from the fight. After guns, monarchs could wage war on whoever they damn well pleased. Local aristocrats lost influence, though this did not mean some kind of more egalitarian setup. It just meant that the central authority’s power was even less questioned than before.
How to Use This in Your Story
If your story focuses on a powerful noble house, they will certainly notice the effects of guns. Whereas before the king sought their implicit permission before marching to war, now he keeps only his own council. In fact, without the power of their knights, the house is in danger of crumbling. Before, they could keep rivals at bay through the threat of military force but not any longer.
The rise of musket-armed peasant armies is also the perfect recipe for an uprising of the common people. If the king spreads firearms and the skill to use them among the disenfranchised masses, this strategy might not work out as he hoped. History is full of uprisings, with some particularly striking examples in Edo Period Japan. While these uprisings were rarely successful, your characters might be the ones to tip the balance. Imagine the conflict brought to your setting when the queen is deposed and a people’s council set up in her place.
4. Swords Get Smaller and Lighter
While swords were rarely a soldier’s primary weapon on the battlefield,* in pre-firearm days, they still had to punch through an enemy’s armor to reach the delicious meat beneath. A sword wouldn’t be much use if it was stopped by a few interlocking rings of metal or a piece of boiled leather.
Then guns hit the field, and armor’s days were numbered. Soon, even the formerly untouchable plate mail was a thing of the past. But swords didn’t go away; they changed focus. As armor waned, swordsmiths were free to experiment. The changes were stark. Gone were the heavy medieval broadswords, designed to shear or stab through armor via brute force. Slender rapiers, small swords, and eventually the epee soon replaced them.
These new weapons focused on quick, stabbing attacks. Often they lost their cutting edges entirely. Against an unarmored human, it doesn’t take much force to drive a sharpened point through skin and muscle. Speed and precision came to the forefront, resulting in the lightning-quick back and forth of today’s fencing matches.
Guns didn’t make the sword go away. Academies in Europe trained young people to use the sword for deadly effect well into the 1800s and even the 1900s in scattered incidents. The role of the sword simply changed, from a weapon of nations to one of individuals. Even outside the duel, it was useful to have a melee weapon handy in case there wasn’t time to reload a flintlock pistol.
How to Use This in Your Story
Lighter swords inflict a different type of wound. The rapier and its descendants poke small holes in the body rather than breaking bones and cutting tendons. It’s entirely plausible that a trained duelist could take several hits and still fight. The blood loss would slowly catch up with them, perhaps tricking an overconfident character into fighting well past their limits. This is a realistic way for a character to fight on, even after they’ve been injured.
Using swords and guns together gives you even more options. Who doesn’t love a pirate with a pistol in one hand and cutlass in the other? This kind of combat gives you the chance to vary your description so readers don’t get bored. One paragraph your character is blazing away, and the next they’ve locked blades with a bloodthirsty opponent.
When swords and guns are both in play, characters must be skilled in two kinds of combat. Trouble arises when a character is overconfident about their shooting prowess, certain they’ll never need to close in for blade work. The reverse is also possible, with an old-fashioned duelist refusing to learn firearms and then paying for it when battle arrives.
5. Navies Become More Powerful
Naval power has always been important to human civilization. Before mechanical engines, waterborne trade was by far the most important driver of commerce.* Whenever that much money is involved, military might is sure to follow, and countries have had navies almost as long as they’ve known how to build ships.
Navies were also vital for transporting troops. Moving large armies over land was time consuming and difficult. Sailing them over water was a lot easier, providing one had enough ships. But for all that, ships were little more than human delivery systems. Once the soldiers got where they were going, their ships weren’t much use. Naval combat consisted entirely of boarding the other ship to fight it out with blade and spear.
Then cannons entered the picture. It wasn’t long before someone had the bright idea to put these death-spitting metal tubes onto ships. The new men-of-war became floating artillery batteries, capable of incredible destruction. They could bombard port cities, destroy enemy ships at a distance, and provide artillery support for invading soldiers.
Because cannons were heavy, moving them around on land was difficult.* As always, ships proved better suited to the task. Warships boasted heavier guns than any mobile artillery on land. That’s still true today. You won’t see anything the size of an Iowa-class battleship’s main guns deployed on solid ground.
How to Use This in Your Story
If your characters are on a ship, they’ll notice the effects of cannons right quick. Old sailors might reminisce about the good old days, when you had to see the enemy’s face before killing them. Now it’s all about standing off and letting cannons do the work. If your characters own a ship of their own, they’ll be able to project great power. Of course, they’ll have to deal with other, bigger ships.
In a political story, characters will find their nation’s power measured largely by its navy. Even countries with small coastlines will build up massive fleets. Your story could be about a landlocked nation conquering its way to the sea so as to build a navy of its own.
6. Wars Get Larger and Deadlier
War is expensive: the cost of equipment, food, wages, etc. There’s also the cost in human hours. Every person in the army is someone not farming, making clothes, or repairing the sewer system, and that’s not even counting the ones who don’t come back.
Guns reduce the price of war in some ways and increase it in others. First, equipping a soldier with musket and ammunition is a lot cheaper than paying for all the accoutrements of a knight. Second, soldiers need far less time to train with guns than traditional weapons. Because the role of nobles has diminished, the central authority has far more power to recruit soldiers for war.
All of these factors combine to make post-firearms armies far larger than their medieval predecessors. Soldier counts jump from tens of thousands to hundreds of thousands. And that’s where war gets more expensive. Not only are guns incredibly deadly, but there are far more soldiers shooting at each other than ever before.
Loss of life in war shoots up after the firearm,* culminating in the infamously doomed charges of World War One. It’s said that generals are always prepared to fight the previous war, and the cost of that shortsightedness is much greater in the age of gunpowder. Wars jump from small, regional affairs to massive conflicts that span continents.
How to Use This in Your Story
If war is larger, your characters are more likely to be pulled into it. No matter who they are, the king may conscript them into service, giving each a hand cannon and ordering them to shoot some poor fools from the next kingdom over.
War has never been pleasant, but after the introduction of gunpowder, it truly becomes hell. Explosions reign all around your characters; great engines of conflict belch fire and destruction. Terry Pratchett gets it right in Men at Arms, when he describes how easy it is to kill with a gun, how impersonal. His characters are able to reach out and extinguish a life, like snuffing out a candle.
Your characters can face the same thoughts, especially if they come from a culture where swords and bows are the norm. On the other hand, if your setting is full of dangerous megafauna, the ability to quickly mobilize large forces could be very helpful. A fire-breathing dragon might be unbeatable to a small party of adventurers, but the local artillery battalion will fair better.
Guns provide dramatic opportunity and are tragically underused in the fantasy genre. Including them will make your story stand out, but you’ve got to understand the effect they have. You can’t just have one character in your medieval fantasy story using a rifle and call it a day. Knowing what effects firearms will have on your story is important, both for setting consistency and so you can shape the best possible story for your characters.
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