In a society that has relatively plentiful magic, enough that spell casters would be a standard part of any size-able army, would cannons and artillery still develop?

For the purpose of this question lets say we are using a D&D/Pathfinder like system where spell casters get a few spells per day and can throw fireballs and apply battlefield control in a moderate range around themselves but are not cheap to hire and are vulnerable.

Items can be enchanted with either persistent or one-shot magical effects, although that is also not cheap.

  • $\begingroup$ An interesting example of such a world would be the Lightbringer series (by B. Weeks). I think the type of 'magic', though called differently, fits quite well into your restrictions. And yes, there are cannons. :-) It all depends on how powerful magic is, how exhaustible, and how easy to learn, in comparison to cannons. $\endgroup$ – Yellow Oct 21 '14 at 13:46
  • $\begingroup$ chat.stackexchange.com/transcript/17213?m=18235263#18235263 $\endgroup$ – Shokhet Oct 21 '14 at 15:18
  • $\begingroup$ Mostly-ontopic: scifi.stackexchange.com/questions/2611/… $\endgroup$ – user4239 Oct 22 '14 at 16:02

11 Answers 11


Danny Reagan posted an excellent answer for the classical DnD Magic scenario, although we can also watch two other factors:

Development of reliable gunpowder was freaking hard

Alchemists have to experiment with burning and explosives for years and try ever new combinations of getting an explosive reaction, all of which will lead to explosives first and afterwards bring about the idea of using it as the base for cannons. This whole development process will only likely progress if the intermediate goals (heavy burning substance, explosives, unreliable cannons) will already provide any merit. If your magical world already has cheap and safe means of using magic for mining operations and other places where explosives would be needed, it is unlikely someone will do the ludicrous research of highly unstable potions which are hard to handle, hard to dosage and really dangerous for the user...

And without this preliminary steps, it could be possible no one ever invested big resources into the research of explosives - and the resulting application of explosives in the form of fuel for cannons was in reach to be considered.

Magic crossbows and catapults could be better than guns

If you only user Magic in a direct approach with wizards walking around the battlefield throwing fireballs, this will most likely fail in the face of imperialistic warfare, where quantity is the deciding factor on a huge scale. But wizards on the front-lines would be like scientists and technicians using their inventions in battle. If the magic could be applicable to make artifacts, like self-reloading catapults. Magically enhanced projectiles for crossbows, or personal shielding devices for soldiers. If any of these artifacts could be produced beforehand in a big scale, or could be charged by a few wizards before the battle, a few wizards could be enough to provide the army with the means of heavy artillery or personal crossbow-guns with exploding bolts.

Special anti gun magic could be devastating

Another killing blow for guns on the battlefield could be if wizards developed special spells against fire-weapons. It could be an area-effect spell, which makes the air highly flammable, resulting in every shot fired blowing up the user. Or it could be a rain of sparks, which could easily ignite gunpowder reserves blowing everyone up. Or it could be a rune of humidity and rainfall, making everyone soaking wet and rendering all forms of early gunpowder completely useless.

Especially if some magicians have a way of letting your gun explode in your hands and will win two minor battles with it, you will have a hard time finding soldiers who would even want to carry a gun, which is a ticking time-bomb only waiting for a wizard.

Expensive Area-of-effect spells against guns could render them useless for a large-scale army, but still keep them interesting for hunting or single warriors, who hope the wizard won't cast an expensive AOE spell against guns when only a handful soldiers in the army carry guns. It could be an interesting gamble to carry a gun in this world - possibly fatal for the user if they meet the wrong wizard, but otherwise an impressive weapon... Death defying wildwest-like gunslingers, always on the lookout for wizards, their nemesis.

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    $\begingroup$ This is a beautifully creative comment. One thought that does come to mind is that while necessity may slow innovation of gunpowder, the existence of magic may speed it along. Maybe instead of purely chemical reactions, magical explosive powders may be created by wizards safe at home and stockpiled for war, serving the same role as traditional gunpowder until non-magical inventors get around to figuring the traditional stuff out. $\endgroup$ – Nicholas Oct 21 '14 at 14:37
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    $\begingroup$ Additionally, if the magic system isn't capable of mass-producing magical items (and not all soldiers are capable of learning combat-applicable magic), weapons such as cannons and guns may be invented to fill the gaps in magical offense. $\endgroup$ – Brian S Oct 21 '14 at 16:21
  • $\begingroup$ +1 Especially for throwing the idea of anti-firearms-magic and magical equipment instead battle-mages. As Danny Reagan points out, if mages' spells are limited, traditional and magical weapons become a better option if enchantments can last for at least a few days. $\endgroup$ – 3C273 Oct 21 '14 at 17:00
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    $\begingroup$ If mages are limited in their spellcasting, I see them more realistically serving as intelligence and what would be in modern term "electronic warfare" then firepower. If you had the choice between a fireball that will kill 10 soldiers or a clairvoyance spell that will save 200 of yours. I would take the utility spell. Not to say a magic attack couldn't be used as a panic option, but I see more standard warfare supported by magic than outright magic warfare. $\endgroup$ – 3C273 Oct 21 '14 at 17:03
  • $\begingroup$ @3C273 That highly depends on the nature of the magic. A society with highly restrictive magic will develop in a completely different way than a society where magic is extremely plentiful. It also depends on the nature of the magic as some fiction places restrictions on how a mage might develop their magic, while others will allow a mage to develop their magic in any way that they can imagine. I could see societies develop extremely different due to this, not to mention what resources are available for non-magical development. $\endgroup$ – Thebluefish Oct 21 '14 at 23:20

The severely limited nature of combat magic in D&D/Pathfinder magic systems would render cannons a powerful innovation on the battlefield.


Normally, generals would have had to rely on handfuls of overpaid and vulnerable wizards to do the work of destroying enemy fortifications and breaking up enemy troop concentrations. Having your wizards throw a few fireballs at the castle every morning and then slack off for the rest of the day would frustrate military leaders to no end.

Cannons, on the other hand, will fire repeatedly all day as long as shot and powder are available. (Barring the occasional misfire of course)

Rate of Fire

An average wizard (level 5 in pathfinder, for example) can cast one or two fireballs every day, barring lots of expensive magical items. To cast meteor shower, you would need a level 17 wizard at least. (In real terms, that's a twice in a life-time grand-high-master-of-the-mystical-arts-sorry-I-only-do-Wednesdays kind of wizard)

A medieval cannon can fire, with a competent crew, 10 rounds every hour. Each doing the damage of a fireball or more. With a small battery of six cannon, with one inevitably out of service for repair or cleaning, that's 50 shots every hour.


While casting a militarily significant number of cannons is far from cheap, hiring wizards is hardly cost-effective either. Even assuming a royal cadre of wizards who work for the privilege of their heads on their shoulders, you still have to factor in the cost of training them for 30 years to get them even up to one fireball a day.


Cannons just have too many benefits over wizards and magic to be rejected by a magical society. The development of cannons might even be hastened by a magical society, as the wizard class provides a constant demand for alchemical manufacture and innovation. This could lead to an early development of gunpowder. Access to magical forging techniques could even make cannon cheaper to cast, further speeding their adoption.

Over time, wizards might be relegated to support roles. Using their shields, invisibility, and flight to grant the army tactical advantages that technology won't provide for more than half a millennium of development. Now that's job security.

  • $\begingroup$ In the beginning few minutes of the battle the rate of a cannon would be much higher. A cannon could be fired 3 to 4 times per minute in the 17th century. This was, however, only valid for the first few shots, as the cannon would overheat if fired more than a couple of times this fast. Still, for opening the battle, the rate would be much more than 10 per hour. The 10 per hour will only be valid after the beginning of the battle, due to the cannons overheating if they kept up their maximum possible firing rate for too long. $\endgroup$ – vsz Oct 21 '14 at 6:18
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    $\begingroup$ @vsz I was using figures from the War of the Roses, using far more primitive cannon. $\endgroup$ – Danny Reagan Oct 21 '14 at 11:01
  • $\begingroup$ A Mage on World of Warcraft can cast a fireball at a rate of around 1,000 an hour. That's a pretty high rate. $\endgroup$ – corsiKa Oct 21 '14 at 18:47
  • $\begingroup$ @corsiKa: I guess that in WoW cannons would fire much faster than in reality as well. In MMO RPGs rates of fire of every weapon are modified to avoid players' frustration. Also, the magic system considered here (a mage can cast few spells a day) is clearly different from WoW-like magic. $\endgroup$ – Pavel V. Oct 22 '14 at 8:46
  • $\begingroup$ When your cannon starts to overheat, you have a wizard who can throw a cantrip on it to cool it down. A first-level wizard would suffice. $\endgroup$ – Mary Jun 21 '20 at 21:03

Just to add to the discussion, it may really depend on the use that is made of magic in your world.

In the Lord Darcy serie of books for exemple, while magic is extensivelly used in day-to-day life, it is not on the battlefield, as using magic on another human is seen as black magic. This is something that can be "seen" by some mage and priest, and is not taken lightly by the church.

Thus the armies (and weapons) evolved as our own world and are quite similar, with sword, pistols and cannons. Except of course the presence of healers alongs the medic :)

  • $\begingroup$ Interesting way of looking at things....using magic in war absolutely does depend on prevailing culture, I never thought of that. +1 $\endgroup$ – Shokhet Oct 21 '14 at 20:21
  • $\begingroup$ In the Lord Darcy series, magic is used on the battlefield, so long as you aren't using it directly on the other side. In "The Spell of War", the Angevin unit Darcy is a junior officer in is outnumbered by a larger Polish force protecting an artillery position. It's eventually realized that the cannon are unprotected by any real force and the soldiers are illusions. $\endgroup$ – Keith Morrison Nov 28 '17 at 23:05
  • $\begingroup$ Fait point, but it's more "as long as you doesn't hurt the other side". In "all mage!" (Tous magiciens !" in french), a magical gun is used to perturb the opposition. A test on the heroes showed him nearly incapable of loading, aiming and shooting a gun to a static target in the same room. $\endgroup$ – PATRY Guillaume Dec 1 '17 at 16:15

The answers already given cover a lot of excellent aspects, but I think it's important to mention some another reason for creating non-magical weapons. If only certain people can be spellcasters, even if it's a majority, the ones that can't will probably grow to fear or envy them, especially if they're often used in battle. This alone could probably cause enough people to dedicate their lives to making weapons that could out-match a wizard. Not only could this eventually lead to conventional weapons and artillery, they would probably all be hardened against magic users' offense and defense. In the event that a fearful non-spellcaster came into power, it could escalate the situation considerably.

  • $\begingroup$ Great idea!! I like that. $\endgroup$ – Shokhet Oct 21 '14 at 20:17

I would say that traditional cannons may develop, but would not be as plentiful as in our world. I like to imagine in worlds where magic IS the technology, what would that look like as it began to advance beyond the traditional medieval time period, so I think this is a great question.

If it were an Eberron sort of world, you might see cannons that appear mechanical but are actually powered by magic to some extent (i.e. powder is magically ignited, the missiles themselves are enchanted to cause more damage), or even, my favorite iteration of this idea, cannons that actually just fire bolts of magical energy!


In a society that has relatively plentiful magic, enough that spell casters would be a standard part of any size-able army, would cannons and artillery still develop?



  • Stonewalls > Fireballs: As awesome as fireballs are they aren't going to bring down a fortress.

  • Arrows > Casters: Walls give defenders greater range than the attackers have. CASTERS ARE SQUISHY. (I am playing a Sorc in 5e right now)

  • Alchemy is more common than casting: Anyone can do it, therefore, more common.

  • Not everyone can cast: In the end unless everyone, or maybe even just a solid majority are casters there will be a need for non-magical solutions to problems. Sure most armies may have casters but does the guy building a road, the guy operating a mine? Necessity is the mother of invention sure but non-combat necessity can still lead to combat functionality.

  • Most but not all: Most sizable armies can cast, again that means many smaller bands of soldiers, or maybe brigands or pirates may not. They would need the firepower to fight the man...so to speak.

I think the most logical scenario is enchanted items. It gives you serious firepower and keeps casters out of siege combat...which is not their ideal place to be. I think this would result in less or at least slowed improvement on the technology side as they would/could be augmented in their basic form by magic.


I gave +1 to Danny Reagan's "yes" answer, and think he implied but missed one powerful factor: human nature.

A cannon can be operated by the lowest peasant, with some basic training. Cannons can be manufactured by most anyone, with the proper supervision. Cannons do not walk around of their own volition and are large enough that they won't show up in your bedroom or at your coronation, etc.

Powerful mages, on the other hand, might walk into your bedroom or saunter to your coronation. They are no doubt specially gifted, specially trained, and ambitious people who have great innate power and prestige/fear.

Which would you prefer to rely on as a King? A powerful group of elite mages, or some cannon?

Granted, any army needs elite troops and generals and the like, all of whom might turn against you or act for their own gain, but mages take all of that to another level. Depending on how magic works, they may essentially be well-educated, sentient, highly-mobile cannons with stealth and mind control abilities.

So, for straightforward duties, like scattering enemy troop concentrations or blasting fortifications, cannon would be a much safer alternative to magic. (And that's not even considering magic-enhanced cannons.)


Sure they would, but depending on the specifics of availability, costs, and what spells are available, how often and in what way they would be used, and how magic would be used to enhance, protect, or counter them.

Unless they haven't been figured out yet (as for much of Earth's medieval period), or circumstances lead to reasons not to (such as a strong Wizard's Guild which feels threatened by gunpowder technology, and finds ways to discourage its development and use). Also, if magic includes common enough spells that can do similar things, people might be less eager to develop cannon technology.

Particularly relevant would be spells which could protect against, and/or control the flight of, missiles including cannonballs, as well as magical means of drenching (or better, setting fire to) enemy gunpowder.


spell casters get a few spells per day and can throw fireballs and apply battlefield control in a moderate range around themselves but are not cheap to hire and are vulnerable.

Items can be enchanted with either persistent or one-shot magical effects, although that is also not cheap.

Hmm... To me, those two points combined spell out one thing: magical cannonballs!

The cannon provides a greater range than a spellcaster, magic provides a greater effect (area, incendiary, wall-busting, etc.) than a regular cannonball.

Then again, there would be little reason to use cannons over catapults in that scenario.


I remember reading Joel Rosenberg's "Guardians of the Flame" series many years ago. In it guns and gunpowder are introduced to a society that has magic and therefore very little technology. Initially the new technology is unstoppable, but after a while a magical alternative is developed - water is heated to high temperature under pressure then magically frozen in that state, producing a powder. This is stable until water is added, causing the powder to revert to it's heated, pressurised state. This becomes the magical alternative to gunpowder.

There are several answers here that mention how hard it is to develop gunpowder. In a magical society a magic alternative to gunpowder could be developed more easily, having all of the same properties but not requiring the same level of technology.

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    $\begingroup$ I love the diametric opposition of the magic steam powder...lit by water instead of fire. $\endgroup$ – Marshall Tigerus Mar 13 '17 at 19:13

There's a couple of great answers here, so let me just add another point.

A magic-using society would very likely make cannons much easier to make. In history, making cannons was extremely expensive and time-consuming. The steel you need for a cannon is considerably different from the steel needed for a blade (which is why bronze was mostly preferred), and it needs a lot of it.

Handling the weapons and their fuel was hazardous and complicated. It's very easy to make gunpowder explode, and it's easy to let it get wet etc. thus making it useless.

Both of those points can be much improved by magicians. A safer explosive could be made, and there are even some interesting options like using a powder that is inert until activated by the magician before battle. Enchanted materials and improved analysis techniques could lead to cheaper, lighter and more reliable cannons.

All in all, you might in fact be ending up with more cannons than those used in e.g. historical Europe (see how cannon numbers changed when proper steel was introduced, and as it got cheaper).

In fact, it's hard to imagine how magic users could ever be more useful in a direct combat role, rather than as support troops. Healing, shielding, visibility, communication, diversion... Does the fireball really sound all that useful compared to all the interesting things magic-users could do? I'd expect that only rogue mages would ever be involved directly in a battle, throwing fireballs around.

  • $\begingroup$ Not to mention that you need a cannon + powder + shot, which makes a complicated supply chain that may be hard to maintain (not to mention the manufacture of the three) and also crew trained to fire and to aim the damn thing (not as easy as it sounds). Whereas a wizard uses the same fuel as a common soldier that you will need to procure anyway. $\endgroup$ – Marshall Tigerus Mar 13 '17 at 19:15
  • $\begingroup$ You can stockpile cannon and shot (and gunpowder, for a while). Not so much wizards. $\endgroup$ – Keith Morrison Nov 28 '17 at 17:00

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