Worlds of Design: How Big is Your Army?

For those who prefer "realistic" numbers in RPGs: Inflated numbers of combatants for battles litter history books, derived from wildly inaccurate contemporary histories. We can do much better in figuring out actual numbers.

Picture courtesy of Pixabay.​

Some GMs don't care about practical limitations, and will happily claim an army is hundreds of thousands strong. But that kind of nonsense will put off some players, breaking their immersion in the setting, destroying their suspension of disbelief - because it's nonsense, barring extraordinary magic or combatants who don't need to eat!

As player characters progress to greater capabilities, some may become involved in warfare. I'm discussing this for the benefit of those GMs and game designers who want their world to make sense. Keeping the numbers down may also help when you're trying to fight out a battle on the tabletop in a campaign.

Army Inflation​

Many decades ago, I recall being in awe as I read about one of three Battles of Panipat (India) involving 600,000 men according to accounts of the time. The numbers were repeated in a 20th century dictionary of battles, yet sounded immensely inflated. They were, as are the claims from ancient and medieval times for many other battles. Logistics (supply, more or less) limits the size of pre-"modern" armies. In order to feed them and their horses, you can only concentrate so many in one place (not counting cities that have developed long complex supply chains, though few cities exceeded the size of armies in pre-modern times). Modern estimates for any of the three Battles of Panipat are for less than 150,000 total combatants in the 18th century battle, less than 100,000 for each of the older battles, not 600,000.

I find that counting, or relying on someone else to count, helps solve many questions; but even the commanders of pre-modern armies didn't know how many troops they had. So we resort to other methods.

Let's take some examples of battle sizes.

The Battle of Hastings and Marathon​

In the late 19th century, estimates for the size of armies at the Battle of Hastings (Norman conquest of England) were around 25,000 each. Today as we understand circumstances better, estimates are typically 6,000-8,000 per side. Not a big battle, but huge in its results.

Numbers cited for the Battle of Marathon (490 BCE) by the ancients are wildly unreliable. A method used by modern historians to try to achieve a reasonable range, was to compare the size of the (excavated) Persian camp to the size of other camps where numbers are fairly well known (as in the past few centuries, or some Roman camps). The Persian camp couldn't possibly accommodate anything like the numbers cited.

Another way to estimate number of participants is to know the number of men manning a ship. Greek and Persian triremes were quite standardized, and we know their size from excavating sheds where triremes were stored. If we know that the complement was typically 200 men, we can calculate that 371 ships (reported in detail by Herodotus for the Battle of Salamis) equals 74,200 Greeks. A similar logic can be applied to Viking armies, but here many historians distrust the number of ships reported by contemporaries, so we end up with estimates varying from hundreds to thousands.

Yet I still see wildly inflated numbers from works of the time repeated in modern day historical books.

Barbarian Invasions​

How about numbers of "barbarians" in ages of invasion? We have almost no reliable numbers. One that is reliable is the number of Vandals (with some Alans) crossing from Iberia to Africa, because the Romans (who transported the Vandals to participate in a civil war in Africa) had to know how many ships they needed. I've seen 80,000 quoted by historians, including women and children. Which likely meant no more than 20,000-25,000 warriors.

The Battle of Towton​

What may have been the bloodiest battle ever fought on English soil, the Battle of Towton (1461), involved 50,000-65,000 men counting both sides - about 1-2% of the population of England at that time!

Modern Battles​

Even in Napoleonic times, when roads were much improved and the supply system was designed to cope with large armies and rapid movement, the concentration of more than 100,000 on a side was quite rare, and confined to later in the war (Borodino, Leipzig for example)

The bloodiest battle of the American Civil War (Gettysburg) involved less than 100,000 on either side. The largest number of one side in any battle was Chancellorsville (133,000 Union). These were three and four days battles, not a single day, in times when railroads made supply immensely easier.

Contrast this with notions/claims of many hundreds of thousands in much more primitive circumstances. Such high numbers simply aren't possible, nor was there any way for contemporaries to know actual numbers.

Armies in Your Campaign​

When you run an RPG campaign involving warfare, you don’t generally need to get into details of latrines, camp followers, and pay, but you might want to recognize the difficulties involved in moving and maintaining very large numbers of troops. Most warfare in the melee age was “small war” that involved hundreds rather than thousands, and rarely tens of thousands let alone hundreds of thousands.

I used to live in “Battle Creek” Michigan. That eponymous “battle” involved all of . . . three men (no deaths). A castle could be held by less than a hundred men, unless the attackers were highly motivated and very numerous.

My advice is, forget the vast numbers and focus on interesting interactions.

Your Turn: What are the most numerous armies that have ever actually fought out a battle on the tabletop in your campaign?

 

[Redwizard007]

Infinite ammo, no reloading time (firearms), can’t be taken away. I’d say that has an impact.

An impact, yes. A large impact, thats more complicated.

While the cost savings across an army of cantrip spanners would be dramatic in the field compared to ammunition using archers, only the most high-magic settings have enough casters to pull that off. In the cases where it's doable, absolutely a huge advantage.

For an individual caster vs an individual archer it would probably be negligible, and easily offset by the +1 or 2 to damage of archers (via dex bonus to damage.)

 

[kigmatzomat]

Infinite ammo, no reloading time (firearms), can’t be taken away. I’d say that has an impact.

"Can't be taken away" has the opposite side of the coin called "can't be shared or given away". You only took an archer's bow when you killed/injured them (or they were routed and dropped their weapons to run faster). If a caster dies (or is blinded) it is like breaking their bow and burning all their ammo. Each cantrip caster might be able to move faster/go farther by not carting ammo, but the loss of each one is more significant.

Cantrips have shorter range than bows, maxing out at 120ft (240ft with feats) vs 320-600ft with bows. It also means that cantrip casters would be in range of light cavalry archers with no way to counter...other than using their own bows.

The need for line of sight rather than ballistic arched fire limits their usage as that is how archers shot over their own army.

Firearms, even pre-matchlock micro-cannons, had the advantage that you could train peasants how to hit the broad side of a barn with their proto-shotgun in just a few days and then you could focus on firing & reloading sequences.

Last I checked, cantrips can only be learned by someone who gains a spellcaster level or who has reached a feat level to get Initiate. That isn't something you can make happen with 500 villages you pressed into service.

Similarly archery is a skill that requires extensive training. Not as much for "hit the broad side of the barn" but to do it for hours. A bow requires both strength and stamina to be able to fire multiple arrows per minute for hours, not to mention massed fire requires pulling, and holding, the bow. That takes far longer IRL and in game needing to level up.

Crossbows were a stopgap. On one hand, massed fire was easy as you could leave a crossbow cocked for extended periods with no wear and tear on the weilder and it was moderately easy to get "hit that army" accurate. But it still required a non-trivial amount of muscle to draw the string over and over.

The equivalent of Special Ops (which are essentially Adventurers in service to a realm like the semi-fictional Three Musketeers) would have spellcasters with cantrips, much like they use silenced weapons, which are likewise not impactful to most armies as a whole. But that gets into a whole other discussion. (Fwiw, my current group of six 12th characters can all cast 2 or more cantrips and at least one first level spell)

 

[overgeeked]

"Can't be taken away" has the opposite side of the coin called "can't be shared or given away". You only took an archer's bow when you killed/injured them (or they were routed and dropped their weapons to run faster).

Also can't be picked up by the enemy.

If a caster dies (or is blinded) it is like breaking their bow and burning all their ammo. Each cantrip caster might be able to move faster/go farther by not carting ammo, but the loss of each one is more significant.

And when they recover it's like getting the bow back with infinite ammo. Yes, casters are rare and special. That's just as true for this caster as the casters who're dropping all your rituals in the previous post.

Cantrips have shorter range than bows, maxing out at 120ft (240ft with feats) vs 320-600ft with bows. It also means that cantrip casters would be in range of light cavalry archers with no way to counter...other than using their own bows.

In range, yes. But not necessarily in line of sight. Being smaller they can go places light cavalry cannot and hide easier.

The need for line of sight rather than ballistic arched fire limits their usage as that is how archers shot over their own army.

If we're using real-world mechanics, yes. But in D&D world, all ranged attacks need line of sight or they have disadvantage (PHB, p194).

Last I checked, cantrips can only be learned by someone who gains a spellcaster level or who has reached a feat level to get Initiate. That isn't something you can make happen with 500 villages you pressed into service.

Which is the same restriction that all the spells discussed so far have. It's no different here. So yes, any and all casters are equivalent to the Special Forces.

Firearms, even pre-matchlock micro-cannons, had the advantage that you could train peasants how to hit the broad side of a barn with their proto-shotgun in just a few days and then you could focus on firing & reloading sequences...

Similarly archery is a skill that requires extensive training. Not as much for "hit the broad side of the barn" but to do it for hours. A bow requires both strength and stamina to be able to fire multiple arrows per minute for hours, not to mention massed fire requires pulling, and holding, the bow. That takes far longer IRL and in game needing to level up.

Crossbows were a stopgap. On one hand, massed fire was easy as you could leave a crossbow cocked for extended periods with no wear and tear on the weilder and it was moderately easy to get "hit that army" accurate. But it still required a non-trivial amount of muscle to draw the string over and over.

Sure. But D&D doesn't make that distinction. There's no mechanics for training up the peasantry to sort of use weapons. Either they're leveled and are proficient or they're peasants and are not. A referee with even a bit of knowledge on the subject would be able to account for this.

The equivalent of Special Ops (which are essentially Adventurers in service to a realm like the semi-fictional Three Musketeers) would have spellcasters with cantrips, much like they use silenced weapons, which are likewise not impactful to most armies as a whole. But that gets into a whole other discussion. (Fwiw, my current group of six 12th characters can all cast 2 or more cantrips and at least one first level spell)

Sure. And again, that also applies to all the spells discussed so far. Casters are rare. Casters able to drop 3rd-level spells are going to be incredibly rare.

 

[Redwizard007]

The need for line of sight rather than ballistic arched fire limits their usage as that is how archers shot over their own army.

Interestingly, there is some debate as to how often ballistic fire was commonly used. Some military historians are suggesting that direct fire was used far more frequently than we previously thought. The theory being that arrows were only likely to be effective against heavy armor when fired in straight lines at shorter distances.

 

[kigmatzomat]

Interestingly, there is some debate as to how often ballistic fire was commonly used. Some military historians are suggesting that direct fire was used far more frequently than we previously thought. The theory being that arrows were only likely to be effective against heavy armor when fired in straight lines at shorter distances.

Oh, it is totally situational. Ballistic fire is never ammo-efficient as arcing fire is subject to more wind and flight time but it can be effective when coming from a flank or by surprise. An inability to do it at all is a limit on tactics.

Even when line of sight exisited, ballistic fire was often done to attack over shields, especially in concert with another unit of archers firing directly at targets. I believe this is how King Harold was injured at the Battle of Hastings. (Also not really modeled in d&d)

If we're using real-world mechanics, yes. But in D&D world, all ranged attacks need line of sight or they have disadvantage (PHB, p194).

That same chapter says "When a creature can't see you, you have advantage on attack rolls against it. If you are hidden--both unseen and unheard--when you make an attack, you give away your location when the attack hits or misses."

This means the indirect-fire archer suffers disadvantage but also gains advantage, for a net zero penalty. Note this applies to shooting over a wall as well as shooting into fog/dust. That's not how the statistics likely work out in the real world but as D&D has never modeled "panicked rout" well, i consider it a wash.

Firearms, even pre-matchlock micro-cannons, had the advantage that you could train peasants how to hit the broad side of a barn with their proto-shotgun in just a few days and then you could focus on firing & reloading sequences

Sure. But D&D doesn't make that distinction. There's no mechanics for training up the peasantry to sort of use weapons. Either they're leveled and are proficient or they're peasants and are not. A referee with even a bit of knowledge on the subject would be able to account for this.

That is because there are no rules in 5e for peasants. In a world of magic, bandits and monsters, what are their abilities? Its all handwavium of "whatever the GM needs"

However basic non-automatic firearms use the same firing skills as crossbows, which are simple weapons. I mean, the point that in real life for more than a thousand years they have proven to be the easiest ranged weapon to learn is the very hallmark of what should be a "simple weapon".

I don't use firearms in my games so its all academic to me.

I personally assume all peasants are proficient in simple weapons just so the city militia is actually able to be somewhat effective against a horde of invaders using spears, javelins, slings and crossbows.

Note:edited repeatedly as the quote tags & I had a fight.

 

[overgeeked]

This means the indirect-fire archer suffers disadvantage but also gains advantage, for a net zero penalty. Note this applies to shooting over a wall as well as shooting into fog/dust.

That’s fair.

That's not how the statistics likely work out in the real world but as D&D has never modeled "panicked rout" well, i consider it a wash.

Not really, but sort of. The older editions had morale as standard, which forced opponents to surrender or flee when their morale checks failed. Considering it was basically impossible to run from a fight, you’d just end up getting free attacks on the back of the monster (sometimes vs a worse AC), with no counterattacks, until they died or the referee gave it to you. That’s pretty close to a panicked rout. But not so much with PCs as they had no morale to fail. Though their retainers and hirelings did.

 

[Peter BOSCO'S]

It'd be interesting certainly to see how that'd work with symmetrical spellcasting. I imagine it'd be similarly effective to pregame prayers for sporting events.

Hi, If it was as bad as WWI casters on both sides would get "Woe" as the resources (lives) spent made the battle a bad deal even if you "won", and that's not even getting into the whole "World War I caused World War II" argument.