How does a wizard fight an army?

[Tanarii]

I was reading an old Dragon mag article last week wherein one of the original authors noted that, in Chainmail, wizards were modeled after artillery. Likewise with magic users in the original D&D game.

Which answers the OP question:
Get your own army to hide behind and give supporting fire to.

[Tespri]

I was reading an old Dragon mag article last week wherein one of the original authors noted that, in Chainmail, wizards were modeled after artillery. Likewise with magic users in the original D&D game. So not just realistically speaking, also gameist speaking. Then again, in WW I they were still attacking in formation, as had been shown to be a bad idea in the US Civil War ... so if you are in a high magic world, yeah, skirmisher formations. In a low magic world, where magic is hard to come by ... maybe not.

WW1 was trench warfare. Traditional formations were abandoned at the time. But yeah there would be pretty much nothing but skirmisher formations. Also to point out volo's guide in here. They make it actually pretty clear on roles of some npc characters. Like even archer has CR of 3.

Sure magic users are "rare" but not any rarer than engineers, medics etc... It just means that they aren't the average folk.

Hey Tespri, perhaps that line of discussion would be better suited for a private message?

But keeping in line with the thread, I think I'd probably field a huge army of Mountain Dwarves.

Every single member of the race is a competent warrior and through Mason's Tools you can have them deal double damage to structures (according ot Xanathar's Guide).

My primary tactic would be the siege the Wizard's castle and get my army out of the field and into his fortification.

No, fits perfectly here. Since what your wizard could actually do to DnD army, depends highly on what sort of armies would people have in DnD world.
You cannot state how you would attack an army if you don't know what sort of army you're attacking.
For some weird reason these people insists that DnD world's armies would be made out of useless garbage that could be wiped out from the map by single spellcaster. Which is a statement that would make no sense realistically. No one in their sane mind would create an army that could be wiped out by single monster or a crazed caster.
Adventurers are generally simply used as covert forces doing surgical strikes. Their role pretty much never is to face army in the field. Take them as highly expensive mercenaries.

[Unoriginal]

. I think it's impossible to defeat an army of significant size, even if they're all CR 1/2, without time and preparation

Interesting hypothesis.

Let's test it, shall we?

Side 1:

500 CR 1/2 hobgoblin soldiers.

Side 2:

Gartok, 1 level 20 hobgoblin Champion Fighter.

Spoiler: Gartok's stats

Show

AC 23 (Plate Armor (magic +2) + Shield + Defense)

HP 224 (15+ (11*19))

STR 20 (15 +2 ASI + Heavy Armor Master)
DEX 8
CON 20 (14+2 + 2 ASI)
INT 11 (10+1)
WIS 13
CHA 12

Initiative: +4 (-1 + 5 (Alert))

Speed: 40ft (Mobile)

Action:

Longsword: +11, 11 damages (1d8+2+5), 15 damages (1d8+2+5) in case of crits.


Fighting Style: Dueling, Defense
Second Wind
Martial Archetype
Ability Score Improvement
Ability Score Improvement
Ability Score Improvement
Action Surge (two uses)
Indomitable (three uses)
Extra Attack (3)


Improved Critical
Remarkable Athlete
Additional Fighting Style
Superior Critical
Survivor

Feats:

Heavy Armor Master
Mobile
Alert

Environment: featureless plain, the sides starting with 150ft of empty terrain between them.
Positioning:

Side 1: 5 ranks of 100 hobgoblins, in a rectangle
Side 2: One guy alone

Magic items: Plate Armor +2 for Gartok

The hobgolin mooks, with their +3 to hit, need a 20 or more to hit Gartok. Which mean only 5% of their attacks will connect, and will deal 9 damages because of the crit, with 7 additional damages if they can use their Martial Advantage, and with -3 damage per hit due to Heavy Armor Master, so 6 normally and 13 wtih MA. Meanwhile, Gartok has +11, and compared to the hobgoblins' AC it means he will hit 70% of the time. His damages are enough to one-shot an hobgoblin on average, crit or not. Which means that for 4 attacks, ~3 will hit and kill.

Initiative: Side 2 wins on average.

Turn 1:

Spoiler

Show

Side 2: Gartok takes the Dodge action, moves 40ft.

Side 1: Attack action with longbow. 500 times. Disadvantage due to Dodge. 1 crit, for a total of 6 damages

Distance remaining: 110ft
Gartok's HPs: 118

Turn 2

Spoiler

Show

Side 2: Gartok takes the Dash action, moves 80 ft, then Action Surge and take the Dodge action.

Side 1: Half of the first rank discard their bow for their shields. The rest take the Attack action with Longbow. 450 time. Disadvantage due to Dodge. 1 crit, for a total of 6 damages.

Distance remaining: 30ft
Gartok's HPs: 172

Turn 3

Spoiler

Show

Side 2: Gartok moves 30 ft. Attack action, 3 killed. Action Surge for Dodge.

Side 1: 3 hobgoblins advance to take the place of those killed, a total of 8 hobgoblins surround Gartok. 8 attacks with Martial Advantage. Disadvantage, no hit.

Due to their comrades being in the way, the hobgoblins past the 2nd rank cannot attack (total cover). First 2 rank: 150 Attack actions with Longbow. Disadvantage. ~0.4 hit, total 5 damages.

Distance remaining: 0ft
Gartok's HPs: 167
Hobgoblin killed: 3

Turn 4

Spoiler

Show

Side 2: Attack action, 3 killed. Second Wind for +25 HPs

Side 1: Movement. Gartok is now surrounded by 48 hobgoblins, in 3 ranks. The archers can't attack him, but don't discard their bow yet. They will discard them progressively to provide backup in melee.

8 hobgoblins can attack. 0.4 hit, total 5 damages

Gartok's HPs: 187
Hobgoblin killed: 6

Turn 5

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 176.5
Hobgoblin killed: 9

Turn 6

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 166
Hobgoblin killed: 12

Turn 7

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 155.5
Hobgoblin killed: 15

Turn 8

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 145
Hobgoblin killed: 18

Turn 9

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 134.5
Hobgoblin killed: 21

Turn 10

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 134.5
Hobgoblin killed: 21

Turn 11

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 134.5
Hobgoblin killed: 21

Turn 12

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 124
Hobgoblin killed: 24

Turn 13

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 113.5
Hobgoblin killed: 27

Turn 14

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 103
Hobgoblin killed: 27

Turn 15 to 171

Spoiler

Show

Side 2: Attack action, 3 killed. Survivor kicks in for +10 HPs.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 102.5 -> 102 ->101.5 etc, take 78 damages until turn 171
Hobgoblin killed: 33 -> 36 ->39 etc, until turn 171 where the last enemy dies

Restults: Approximately 17 minutes after the start of the fight, a Champion emerges from the pile of 500 enemies he just killed.

With no preparation except wearing his equipment and being rested, without much optimisation, and with a single +2 magic item.

[Zonugal]

No, fits perfectly here. Since what your wizard could actually do to DnD army, depends highly on what sort of armies would people have in DnD world.
You cannot state how you would attack an army if you don't know what sort of army you're attacking.
For some weird reason these people insists that DnD world's armies would be made out of useless garbage that could be wiped out from the map by single spellcaster. Which is a statement that would make no sense realistically. No one in their sane mind would create an army that could be wiped out by single monster or a crazed caster.
Adventurers are generally simply used as covert forces doing surgical strikes. Their role pretty much never is to face army in the field. Take them as highly expensive mercenaries.

In your campaign, sure. In others? Maybe not!

So unless you're going to offer some mechanics here, you're just screaming that others need to follow your version of the game.

[Unoriginal]

"No one in their sane mind would create an army that could be wiped out by single monster or a crazed caster."

Yes, they would, because monsters or casters who can do that kind of things are world-shakers who show up maybe once a century. Most humanoids don't have the capacity to become a tenth as strong as that kind of person or creatures.

[Zonugal]

Here is my most basic infantry to send at a wizard.

These guys can be built as commoners (using a stat array of 12, 11, 11, 10, 10, 10) and cost 77 gp to outfit. They also deal double damage to structures and having a working knowledge of fortifications.

Dwarven Soldier
Mountain Dwarf with the Soldier background
Medium humanoid (dwarf), Lawful Neutral
Armor class 15 (scale-mail)
Hit points 9 (1d8+1)
Speed 25 ft.
---
Str 13, Dex 12, Con 13, Int 10, Wis 10, Cha 10
---
Saving Throws --
Skills Artisan's Tools (Masons Tools) +2, Athletics +3, Gaming Set (Dragon Chess) +2, Intimidation +2, and Vehicles (Land) +2
Feats --
Senses passive Perception 8; Darkvision (60 ft.)
Languages Common and Dwarven
Challenge 1
---
Special Abilities
Racial Abilities: Darkvision (60 ft.), Dwarven Resilience, Dwarven Armor Training, Dwarven Combat Training, Stonecunning, and Tool Proficiency
Background Abilities: Military Rank
Class Abilities: --
---
Actions
Hand-Axe. Melee weapon attack: +3 to hit, reach 5 ft., range 20 ft/60 ft., one target. Hit: 4 (1d6+1) slashing damage; light, thrown (20/60)
Light Hammer. Melee weapon attack: +3 to hit, reach 5 ft., range 20 ft/60 ft., one target. Hit: 3 (1d4+1) bludgeoning damage; light, thrown (20/60)
Battle-Axe. Melee weapon attack: +3 to hit, reach 5 ft., one target. Hit: 6 (1d10+1) slashing damage; versatile (1d10)
---
Equipment: a battle-axe, a belt pouch (15 gp), a set of common clothes, a gaming set (Dragon Chess), hand-axe, an explorer's pack, an insignia of rank, light hammer, mason's tools, scale-mail armor, a trophy taken from a fallen enemy (a broken wand)

[the_brazenburn]

Here is my most basic infantry to send at a wizard.

These guys can be built as commoners (using a stat array of 12, 11, 11, 10, 10, 10) and cost 77 gp to outfit. They also deal double damage to structures and having a working knowledge of fortifications.

Dwarven Soldier
Mountain Dwarf with the Soldier background
Medium humanoid (dwarf), Lawful Neutral
Armor class 15 (scale-mail)
Hit points 9 (1d8+1)
Speed 25 ft.
---
Str 13, Dex 12, Con 13, Int 10, Wis 10, Cha 10
---
Saving Throws --
Skills Artisan's Tools (Masons Tools) +2, Athletics +3, Gaming Set (Dragon Chess) +2, Intimidation +2, and Vehicles (Land) +2
Feats --
Senses passive Perception 8; Darkvision (60 ft.)
Languages Common and Dwarven
Challenge 1
---
Special Abilities
Racial Abilities: Darkvision (60 ft.), Dwarven Resilience, Dwarven Armor Training, Dwarven Combat Training, Stonecunning, and Tool Proficiency,
Background Abilities: Military Rank
Class Abilities: --
---
Actions
Hand-Axe. Melee weapon attack: +3 to hit, reach 5 ft., range 20 ft/60 ft., one target. Hit: 4 (1d6+1) slashing damage; light, thrown (20/60)
Light Hammer. Melee weapon attack: +3 to hit, reach 5 ft., range 20 ft/60 ft., one target. Hit: 3 (1d4+1) bludgeoning damage; light, thrown (20/60)
Battle-Axe. Melee weapon attack: +3 to hit, reach 5 ft., one target. Hit: 6 (1d10+1) slashing damage; versatile (1d10)
---
Equipment: a battle-axe, a belt pouch (15 gp), a set of common clothes, a gaming set (Dragon Chess), hand-axe, an explorer's pack, an insignia of rank, light hammer, mason's tools, scale-mail armor, a trophy taken from a fallen enemy (a broken wand)

Just wondering, what's the point of both the light hammers and handaxes?

[Zonugal]

Just wondering, what's the point of both the light hammers and handaxes?

Versatility? Also, I like the idea of Dwarven soldiers having weapons that could also serve as tools if needed.

[KorvinStarmast]

WW1 was trench warfare. Traditional formations were abandoned at the time. But yeah there would be pretty much nothing but skirmisher formations.

Having studied WWI in some detail, I will suggest that you do likewise, as your one sentence summary does not embody all of the forms of war that WW I took, though the trench, artillery, and more lethal rifles and machine guns certainly made their mark. The Germans developed some very effective storm troop tactics (Read Rommel's Infanterie Greift An (Infantry Attacks!) ) for an excellent summary of the better way to deal with the problems that western front static warfare presented, and his success in the Italian / Tyrol campaign). In the first few months of the war the "trench warfare" mode had not yet set in: undispersed infantry attacks ran into the problem of industrial aged warfare again and again. Later on, Somme becomes a well worn example of that problem, but line abreast attacks by the French infantry being disrupted by rifle/artillery/machine gun fire were already well documented in 1914. Verdun is a superb example of the static warfare problem faced on both sides.

Also suggest you look up a bit on the Eastern Front and the campaigns versus the Turks.
Tannenberg, for example, was hardly trench warfare. The more static fighting on the Eastern Front where my grandfather was gassed later in the war was in a more static sector.

[JackPhoenix]

Hey Tespri, perhaps that line of discussion would be better suited for a private message?

But keeping in line with the thread, I think I'd probably field a huge army of Mountain Dwarves.

Every single member of the race is a competent warrior and through Mason's Tools you can have them deal double damage to structures (according ot Xanathar's Guide).

My primary tactic would be the siege the Wizard's castle and get my army out of the field and into his fortification.

Army of half-orcs would be better. Relentless Endurance ensures they survive at least one hit.

Or combined warfare, dwarves for engineers, half-orcs for infantry, elves for ranged support (every elf knows how to use longbow). Stealthed halflings behind everyone else, just because. Too bad tiefling's Hellish Rebuke requires level 3 and has only 60' range, horde of tieflings would be funny against AoE users.

[Unoriginal]

I'd have thought me claiming a Champion can fight an army and win would be met with skepticism.

[Tespri]

In your campaign, sure. In others? Maybe not!

So unless you're going to offer some mechanics here, you're just screaming that others need to follow your version of the game.

In most official campaigns. This includes video game ones as well. In some custom campaigns you probably end up facing some armies, however you're not addressing my argument. There is no reason to assume that some random hobos are only ones who can reach pinnacle of skill and power.

"No one in their sane mind would create an army that could be wiped out by single monster or a crazed caster."

Yes, they would, because monsters or casters who can do that kind of things are world-shakers who show up maybe once a century. Most humanoids don't have the capacity to become a tenth as strong as that kind of person or creatures.

"Yes, they would, because monsters or casters who can do that kind of things are world-shakers who show up maybe once a century. "
You're mixing up legendary monsters here. Even dragonborn army alone would wipe out your imaginary army. In fact dragonborns would be most dominate race. Those "once a century" monsters are something like tarrasque. So again... monsters and magic users aren't as rare as you try to claim them. Official campaigns should already make this clear.

Having studied WWI in some detail, I will suggest that you do likewise, as your one sentence summary does not embody all of the forms of war that WW I took, though the trench, artillery, and more lethal rifles and machine guns certainly made their mark. The Germans developed some very effective storm troop tactics (Read Rommel's Infanterie Greift An (Infantry Attacks!) ) for an excellent summary of the better way to deal with the problems that western front static warfare presented, and his success in the Italian / Tyrol campaign). In the first few months of the war the "trench warfare" mode had not yet set in: undispersed infantry attacks ran into the problem of industrial aged warfare again and again. Later on, Somme becomes a well worn example of that problem, but line abreast attacks by the French infantry being disrupted by rifle/artillery/machine gun fire were already well documented in 1914. Verdun is a superb example of the static warfare problem faced on both sides.

Also suggest you look up a bit on the Eastern Front and the campaigns versus the Turks.
Tannenberg, for example, was hardly trench warfare. The more static fighting on the Eastern Front where my grandfather was gassed later in the war was in a more static sector.

Of course some places were different. Since different technologies and some people were too slow to figure out modern warfare. But people figured out the new meta. Standing in formations and shooting enemies was suicidal given new technological changes.

But yeah... Warfare in DnD world would be drastically different from ancient warfare unless wizards and clerics could cast some protective spells against spellcraft.

[Tanarii]

I'd have thought me claiming a Champion can fight an army and win would be met with skepticism.

Champion capstone changes things a fair amount.

I notice you also assumed the enemy can't fire Longbows through multiple creatures with just the cover penalty.

[Tespri]

I'd have thought me claiming a Champion can fight an army and win would be met with skepticism.

500 troops barely even makes an army. As stated before armies of the ancient times even in one battle did had around 10k people in both sides. This was from city states. Bigger empires had far more than that.

[Unoriginal]

Champion capstone changes things a fair amount.

I notice you also assumed the enemy can't fire Longbows through multiple creatures with just the cover penalty.

You need to see the person to fire at them with your longbow. I dunno for you, but 2-3 ranks for people in front of you generally block my view when I'm at the same height.

500 troops barely even makes an army. As stated before armies of the ancient times even in one battle did had around 10k people in both sides. This was from city states. Bigger empires had far more than that.

Well a Wizard would be unable to defeat 10'000 people, too.

[StoicLeaf]

I'd have thought me claiming a Champion can fight an army and win would be met with skepticism.

OK!

I don't like your calculations! I don't like how you're handling cover.
Let's ignore the hailstorm of arrows and get to the stabby part.

8 hobgoblins can surround gartok with longswords.
another 16 can form a second rank and, with spears, stab gartok.

avg. damage per round for poor ol' gartok (d10s for weapons, plus martial advantage): 24*0.05*25 = 30!
gartok's +10 self heal won't be offsetting that.

[Unoriginal]

In most official campaigns. This includes video game ones as well.

Not true, and video games are irrelevant for 5e.

There is no reason to assume that some random hobos are only ones who can reach pinnacle of skill and power.

Adventurers are not the only ones, but they're among the only ones. The reason to assume that is called "reading the books".

You're mixing up legendary monsters here.

You're arguing the chances of an army vs a level 20 adventurer. Legendary monsters are in the same weight class, if not higher.

Even dragonborn army alone would wipe out your imaginary army. In fact dragonborns would be most dominate race.

No they wouldn't. Yes, Dragonborn got their breath weapons, but once it's used up their mooks are just as tough as any humanoid mooks, and they're far less numerous than humans or dwarves.

Those "once a century" monsters are something like tarrasque.

We were talking about a level 20 magic user, which is just one order of magnitude less rare than a Tarrasque.

So no, it's normal to have armies who can't handle that kind of threat.

So again... monsters and magic users aren't as rare as you try to claim them.

I'm not claiming monsters and magic users are rare. I'm claiming *very powerful* monsters and magic users are rare.

As I've said before, an army will probably have several CR 4-6 casters. It doesn't mean they can handle a Meteor Swarm or other spells of the same caliber.

Official campaigns should already make this clear.

Let's see what the last official campaign says about it, then:

The fort contains a winch for raising and lowering an immense iron chain stretched between the fort and the lighthouse. When the chain is raised, no ship can sail into or out of the harbor. The chain hasn't been raised against attackers in decades, but it's used occasionally to prevent a ship from slipping out of the harbor with criminals or contraband on board. The fort also mounts two ballistas that can launch heavy bolts or canisters of alchemist's fire. Its garrison consists of a noble (the castellan), four veterans (officers), and forty guards loyal to the merchant princes.

Aside from Commander Breakbone, the standard garrison at the base consists of fifty-eight people, though the actual number of effective warriors at any given time is usually lower due to sickness. Breakbone has two captains under his command: Ord Firebeard (LG male gold dwarf veteran) and Perne Salhana (LG female Tethyrian human veteran). Reporting to them is a fighting force comprised of eight veterans and twenty-four guards. This is supplemented by a religious corps of six acolytes led by Sister Cyas (LG female Chondathan human priest of Helm). Technically, the religious templars are part of the fighting force, but in practice, they spend most of their time tending the sick and wounded. Finally, the fort is supported by a ragtag troop of Chultan hunters and scouts consisting of fifteen tribal warriors led by Lorsa Bilwatal (CN female Chultan human scout) and Niles Breakbone's longtime friend, WulfRygor (CG male half elf scout).

Those are exemples of typical professional soldiers holding a fort.

As you can see, the number of veterans is between ~10% and ~30% of the number of guards (or tribal warriors, who have the same CR).

And again, later:

The garrison consists of a castellan named Gruta Halsdottir (LN female Illuskan human knight), three corporals (veterans), and fifty-four privates (guards).

In addition, those who buy a charter can hire up to six Flaming Fist mercenaries (guards) to accompany them for the very reasonable rate of 1 gp per ten day each

So here you go. Guards as the most common professional soldiers AND mercenaries.

[Jack Bitters]

Seems like from all this we should be able to come up with a good mix of NPCs that would make up an army.

I'd also propose that there are two armies: the first army, as suggested by the OP, is full of CR 1/4 and CR 1/2 mooks. Probably mostly non-spellcasters; just an every day low-key medieval army bent on destroying your helpless village. Standard pillage and burn kind of operation. I doubt they are aware of the wizard's existence and proximity to the village. Assume fairly close-packed formations.

The second army would be composed of mostly veterans, guards, priests, and acolytes. Throw in a unit of scouts, as well, and maybe a handful of knights and mages at the core, protecting the leader. They would be hunting the wizard as revenge for the death of the first army; they should be a little more prepared. Assume not-so-closely packed formations.

By the published stats for military garrisons Unoriginal laid out, in a sample of 161 troops, there are:
one knight, one noble, one priest, 2 scouts, 6 acolytes, 15 tribal warriors, 17 veterans, and 118 guards.

EDIT: I realize that this really doesn't help much at all–making the wizard fight two armies–but the differences between the proposed armies are too vast to be ignored.

[Unoriginal]

By the published stats for military garrisons Unoriginal laid out, in a sample of 161 troops, there are:
one knight, one noble, one priest, 2 scouts, 6 acolytes, 15 tribal warriors, 17 veterans, and 118 guards.

Err, just to be clear, you're putting two separate garrisons together, here.

The composition of a garrison is still context dependent, I mean.

[Jack Bitters]

Err, just to be clear, you're putting two separate garrisons together, here.

The composition of a garrison is still context dependent, I mean.

Yeah I just mashed all three of them together. I don't own the source book. Probably not the best way to go about it, but your point more or less stands. At least 8 guards for every veteran/more capable soldier.

[jojo]

Champion capstone changes things a fair amount.

I notice you also assumed the enemy can't fire Longbows through multiple creatures with just the cover penalty.

As was mentioned by someone else, it's better that they form a second rank of 16 with spears.

If they committed to engaging with Longbows they could dash to retreat over the featureless plain provided in the example and attack every other round pretty much indefinitely instead of allowing themselves to become engaged in melee.

500 troops barely even makes an army. As stated before armies of the ancient times even in one battle did had around 10k people in both sides. This was from city states. Bigger empires had far more than that.

Switching to the other side of the argument for a minute... the number of individuals that constitutes an "army" is highly dependent on where, when and who you're fighting. Cortes conquered the Aztec Empire with 500 men, for instance.

As a Wizard working on the "Oh S**T an Army!" Scenario currently defined though I think we'd have to define what winning actually means. Do I absolutely have to run out in my bathrobe, boxers and bunny slippers to murder everyone in sight in order to win?

Personally I think not.

5e allows Wizards a lot of spell-casting flexibility, so even if I didn't intend to cast a particular spell I'm a lot more likely to have it prepared then I would have been in 3.5, Pathfinder or other systems.

Going off of my own play-style for Wizards past... and the assumption that the Army is preparing to move in and establish a siege with the goal of either taking over my city and killing me, or convincing the citizens to hand me over peacefully so I can be killed... and finally that they expect me to prepare to withstand a conventional siege...

I'd probably pop off a simulacrum, using Wish if necessary to keep them occupied and organize my defenses to withstand a siege. At that point I'd probably teleport on over to whatever Kingdom is now bereft of it's army and exploit the situation.

Change my appearance with Alter Self, start bemoaning and lamenting the idiotic actions of the local monarch, casting imprecations of divine intervention against their injustice. Use Mass Suggestion to really make it stick, then gather a really big crowd and gate in a pit fiend, just in case anyone was uncertain of the fact that their king is making god cry sad tears.
Teleport back home in time for a quick luncheon of cold meats and the finest cheeses.
True Polymorph my Simulacrum into a celestial or some other divine messenger and then send him out to tell the Army to GTFO. If they resist have him Smite the leader, then use teleport to send a few high ranking remainders back home to see what kind of destruction a Pit Fiend or Balor managed to wreak over the past couple hours.

Once they're convinced their actions have offended their gods... the Celestial Messenger can make it clear that they just need to bow to you, the mighty magical manipulator, who has been given the power of the Gods to undo the Balor... blah, blah, blah.

You've been scrying this of course, while communicating through Rary's Telepathic Bond with your Simulacrum, so the minute they agree you swoop in to save the day. Although the "avatar" of their god makes a big show of summoning you forth.

Then you banish the Balor, of course with the Celestial you making a big show of channeling their power through you.

Not only have you won, you did it in a manner that convinced the Mundalandians or whatever they're called that you're a divine prophet who speaks with the authority of their god, not just some guy with a wand.

As an added bonus your Simulacrum can't cast a whole lot of spells... but they're still a freaking Celestial, and they can go right ahead and affirm your earthly divinity by writing a new gospel or something...

[Tanarii]

Switching to the other side of the argument for a minute... the number of individuals that constitutes an "army" is highly dependent on where, when and who you're fighting. Cortes conquered the Aztec Empire with 500 men, for instance.

More like 1500.

But more to the point, he did it by making lots of allies among local tribes. Not sure what the numbers are, so to Wikipedia! Pulling numbers from Wikipedia: He started off with 2000 native warriors, for the final push it was 20,000 native warriors. Total belligerents is listed as 80-200 thousand, but it appear that includes all the natives involved in the revolt, not ones directly under his command. "It is well accepted that Cortés’ indigenous allies, which may have numbered as many as 200,000 over the three-year period of the conquest, were indispensable to his success."

Anyway, "army" to me, on a quasi-medieval fantasy setting, has always implied maybe five to twenty thousand standing troops, broken into units of 250 to 1000. For an entire nation. But then, my view of what constitutes an army is heavily influenced by the BECMI War Machine rules and the Gazzateer series for the Known World / Mystara.

[smcmike]

Anyway, "army" to me, on a quasi-medieval fantasy setting, has always implied maybe five to twenty thousand standing troops, broken into units of 250 to 1000. For an entire nation. But then, my view of what constitutes an army is heavily influenced by the BECMI War Machine rules and the Gazzateer series for the Known World / Mystara.

Historical army sizes are REALLY hard to know - even eyewitnesses may not have a good estimate, and may have reason to inflate or deflate the numbers, and many accounts are written by people who never saw an army in their life, and who may have their own biases.

That being said, five to twenty thousand seems like a reasonable range for a serious army. I would quibble with the “standing troops” part, since there is considerable variation in terms of the professionalism of armies in different times and places, and plenty of armies were not composed of “standing troops.”

[Citan]

Interesting hypothesis.

Let's test it, shall we?

Side 1:

500 CR 1/2 hobgoblin soldiers.

Side 2:

Gartok, 1 level 20 hobgoblin Champion Fighter.

Spoiler: Gartok's stats

Show

AC 23 (Plate Armor (magic +2) + Shield + Defense)

HP 224 (15+ (11*19))

STR 20 (15 +2 ASI + Heavy Armor Master)
DEX 8
CON 20 (14+2 + 2 ASI)
INT 11 (10+1)
WIS 13
CHA 12

Initiative: +4 (-1 + 5 (Alert))

Speed: 40ft (Mobile)

Action:

Longsword: +11, 11 damages (1d8+2+5), 15 damages (1d8+2+5) in case of crits.


Fighting Style: Dueling, Defense
Second Wind
Martial Archetype
Ability Score Improvement
Ability Score Improvement
Ability Score Improvement
Action Surge (two uses)
Indomitable (three uses)
Extra Attack (3)


Improved Critical
Remarkable Athlete
Additional Fighting Style
Superior Critical
Survivor

Feats:

Heavy Armor Master
Mobile
Alert

Environment: featureless plain, the sides starting with 150ft of empty terrain between them.
Positioning:

Side 1: 5 ranks of 100 hobgoblins, in a rectangle
Side 2: One guy alone

Magic items: Plate Armor +2 for Gartok

The hobgolin mooks, with their +3 to hit, need a 20 or more to hit Gartok. Which mean only 5% of their attacks will connect, and will deal 9 damages because of the crit, with 7 additional damages if they can use their Martial Advantage, and with -3 damage per hit due to Heavy Armor Master, so 6 normally and 13 wtih MA. Meanwhile, Gartok has +11, and compared to the hobgoblins' AC it means he will hit 70% of the time. His damages are enough to one-shot an hobgoblin on average, crit or not. Which means that for 4 attacks, ~3 will hit and kill.

Initiative: Side 2 wins on average.

Turn 1:

Spoiler

Show

Side 2: Gartok takes the Dodge action, moves 40ft.

Side 1: Attack action with longbow. 500 times. Disadvantage due to Dodge. 1 crit, for a total of 6 damages

Distance remaining: 110ft
Gartok's HPs: 118

Turn 2

Spoiler

Show

Side 2: Gartok takes the Dash action, moves 80 ft, then Action Surge and take the Dodge action.

Side 1: Half of the first rank discard their bow for their shields. The rest take the Attack action with Longbow. 450 time. Disadvantage due to Dodge. 1 crit, for a total of 6 damages.

Distance remaining: 30ft
Gartok's HPs: 172

Turn 3

Spoiler

Show

Side 2: Gartok moves 30 ft. Attack action, 3 killed. Action Surge for Dodge.

Side 1: 3 hobgoblins advance to take the place of those killed, a total of 8 hobgoblins surround Gartok. 8 attacks with Martial Advantage. Disadvantage, no hit.

Due to their comrades being in the way, the hobgoblins past the 2nd rank cannot attack (total cover). First 2 rank: 150 Attack actions with Longbow. Disadvantage. ~0.4 hit, total 5 damages.

Distance remaining: 0ft
Gartok's HPs: 167
Hobgoblin killed: 3

Turn 4

Spoiler

Show

Side 2: Attack action, 3 killed. Second Wind for +25 HPs

Side 1: Movement. Gartok is now surrounded by 48 hobgoblins, in 3 ranks. The archers can't attack him, but don't discard their bow yet. They will discard them progressively to provide backup in melee.

8 hobgoblins can attack. 0.4 hit, total 5 damages

Gartok's HPs: 187
Hobgoblin killed: 6

Turn 5

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 176.5
Hobgoblin killed: 9

Turn 6

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 166
Hobgoblin killed: 12

Turn 7

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 155.5
Hobgoblin killed: 15

Turn 8

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 145
Hobgoblin killed: 18

Turn 9

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 134.5
Hobgoblin killed: 21

Turn 10

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 134.5
Hobgoblin killed: 21

Turn 11

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 134.5
Hobgoblin killed: 21

Turn 12

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 124
Hobgoblin killed: 24

Turn 13

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 113.5
Hobgoblin killed: 27

Turn 14

Spoiler

Show

Side 2: Attack action, 3 killed.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 103
Hobgoblin killed: 27

Turn 15 to 171

Spoiler

Show

Side 2: Attack action, 3 killed. Survivor kicks in for +10 HPs.

Side 1: 3 moves to replace them. 4 hobgoblins attack, the 4 others Help. 0.8 hit, total 10.5 damages

Gartok's HPs: 102.5 -> 102 ->101.5 etc, take 78 damages until turn 171
Hobgoblin killed: 33 -> 36 ->39 etc, until turn 171 where the last enemy dies

Restults: Approximately 17 minutes after the start of the fight, a Champion emerges from the pile of 500 enemies he just killed.

With no preparation except wearing his equipment and being rested, without much optimisation, and with a single +2 magic item.

Hey ;)

Interesting exercise, but unless I'm totally out of my mind there are several big flaws in how you resolve the fight from the context you set.
Specifically that part...


Positioning:
Side 1: 5 ranks of 100 hobgoblins, in a rectangle
Side 2: One guy alone

Magic items: Plate Armor +2 for Gartok

The hobgolin mooks, with their +3 to hit, need a 20 or more to hit Gartok. Which mean only 5% of their attacks will connect, and will deal 9 damages because of the crit, with 7 additional damages if they can use their Martial Advantage, and with -3 damage per hit due to Heavy Armor Master, so 6 normally and 13 wtih MA. Meanwhile, Gartok has +11, and compared to the hobgoblins' AC it means he will hit 70% of the time. His damages are enough to one-shot an hobgoblin on average, crit or not. Which means that for 4 attacks, ~3 will hit and kill.

Initiative: Side 2 wins on average.

Turn 1:

[SPOILER]Side 2: Gartok takes the Dodge action, moves 40ft.

Side 1: Attack action with longbow. 500 times. Disadvantage due to Dodge. 1 crit, for a total of 6 damages


Then (I won't copy past all) you suppose that in following turns Champion Dashes with Action Surge thus putting himself in range for attacks in next turn, and goblins react by setting up shields.

First, on any turn, the number of attacks that hit will still be 5%, with or without disadvantage: between 1 and 1, not big of a difference right? Second, there is absolutely no reason why ALL hobgoblins wouldn't shoot, as you said.
So there are 500 attacks. So number of hits will be 500*(5/100) = 5*100*5/100= 25 attacks hitting.
Meaning, on a single turn, Champion will suffer an average of 25*6 (no way to check what Martial Advantage for now so I'll put out aside) at the very least: 25*6=150.
So technically just three turns would be enough to shut him down, even with Second Wind and Champion's regen in play.

Second, there is no reason why Hogbolins wouldn't back off to keep ideal range as long as possible, especially since disadvantage sources don't stack.
So if Hobgoblin's speed is 30 feet, then without Dashing Champion won't get to them before more than 5 turns.

Third, there is no reason why once Champion gets into close range, the closest Hobgoblins would NOT use Dodge themselves to provide some meat shield while their friends shoot arrows (again, they don't care about providing cover because 1 is 1 so disadvantage changes nothing here). Significantly lessening Champion's chance to hit since their AC is 18.
Alternatively, they could also spend a handful of them to Shove the Champion, then another handful to Grapple him: now Champion is restrained and would need to spend an action to break free.

Conclusion: with that build and that strategy, your Champion will be toast in a very few turns, although he may get some personal satisfaction from killing a few ones before falling.

For a Fighter to win, you'd actually need a hefty multiclass in either Life Cleric 1 + Bard 6 for Aura of Vitality, healing yourself with a bonus action (note that I'm unaware of the Xanathar's spells, maybe better option) or into Fiend Warlock 7 to start fight with a Fireball, then Eldricht Blast (providing THP), then another Fireball, quickly reducing the number of enemies.
Or Divine Soul Sorcerer to further boost your hp with Extended upcast Aid and buff yourself with Heroism.
Or any caster that can provide Blink, which is in this kind of situation the best defense spell you could get EVER.
Or Greater Invisibility paired with Elven boots and Rogue 2 to Hide every turn.

Or, simpler, Eldricht Knight with Sharpshooter and either Mobile or Athlete: casts Haste and kite the poor army (although this would require quite a big plain XD), or run far, use Mold Earth / Minor Illusion to create a cover and prone yourself behind, then on your turns stand up, shoot and prone again or back away to create another cover further.

[Tanarii]

If you need a 20 to hit and you have disadvantage, you have a 1/400 chance of hitting. 0.25%, Not 5%.

[Unoriginal]

First, on any turn, the number of attacks that hit will still be 5%, with or without disadvantage: between 1 and 1, not big of a difference right? Second, there is absolutely no reason why ALL hobgoblins wouldn't shoot, as you said.
So there are 500 attacks. So number of hits will be 500*(5/100) = 5*100*5/100= 25 attacks hitting.
Meaning, on a single turn, Champion will suffer an average of 25*6 (no way to check what Martial Advantage for now so I'll put out aside) at the very least: 25*6=150.
So technically just three turns would be enough to shut him down, even with Second Wind and Champion's regen in play.

Disadvantage play a big role. You only have 0.25 chances to get a crit when you have Disadvantage, not 5%. So no, this part of my calculation is accurate.

Second, there is no reason why Hogbolins wouldn't back off to keep ideal range as long as possible, especially since disadvantage sources don't stack.
So if Hobgoblin's speed is 30 feet, then without Dashing Champion won't get to them before more than 5 turns.

In theory, yes, but you're talking about 500 troops having to manoeuvre at once, to fight one guy. Hobgoblins might be disciplined, but they're also arrogant and they don't meet someone who can survive a volley of 500 arrows every day.

Third, there is no reason why once Champion gets into close range, the closest Hobgoblins would NOT use Dodge themselves to provide some meat shield while their friends shoot arrows (again, they don't care about providing cover because 1 is 1 so disadvantage changes nothing here). Significantly lessening Champion's chance to hit since their AC is 18.

Not sure what you mean, here.

Alternatively, they could also spend a handful of them to Shove the Champion, then another handful to Grapple him: now Champion is restrained and would need to spend an action to break free.

A maximum of 8 of them can try that. I admit I haven't done the calculations, but I really don't think that attempting a STR (Athletic) challenge against a lvl 20 champion when you only have +1 is a better use of your time than the Help action.

Conclusion: with that build and that strategy, your Champion will be toast in a very few turns, although he may get some personal satisfaction from killing a few ones before falling.

I disagree. Though I admit he could have more troubles if the hobgoblins used different tactics (like other pointed out, if the hobgoblins had spears he'd die).

In any case, the hobgoblins are an interesting challenge. They actually hit like Ogres, when they have buddies nearby.

[Dudewithknives]

A druid could give an army nightmares.

At level 20 they effectively have subtle spell on all the time.
They can have shift every round as a bonus action to renew HP as needed, even if they do get through the shapeshifter HP you still have your normal HP. (I know that only really works for Moon Druid, but I have literally never seen a druid that wasn't Moon.)
Elemental shape that lasts long enough to essentially be all day. If I was level 20 moon druid I am never going to be in my normal form, I will be in earth elemental form.

Level 20, whatever race, does not really matter, Moon Druid.
Feats: Alert, Magic Initiate: Wizard for Mage armor, Rest to boost Stats.

Round 1, with alert even in Earth Elemental Form you have a +4 on initiative vs their +1. That means that on average you should beat about 60% of them on initiative.
You also have average of 126Hp in elemental form, and resistance to their attacks, and AC 17.
Vs an army of 500.
40% will get an initiative higher than you and attack, that is 200 of them
with an AC of 17 and their to hit bonus of +3, that means they need a 14+ to hit you. That is 60 of them
Each hit will average 5.5 damage. That is 330 damage
You take half damage due to resistance. That makes it 165.
They actually knocked you out of wild shape and did 40 damage or so.

Your initiative:
1. Your action: Cast storm of Vengeance, that thing is 720ft diameter of army killing.
Your Bonus action, Turn into another Earth Elemental
Movement Burrow 20 feet into the ground.
From there just concentrate, many of them will be dead by round 2 on average rolls, all of them will be dead by round 4 if they are still in the area.

Either way there is no way there will be enough to chew through your mountain of HP anymore so feel free to go earth elemental/cast spell/recast wild shape to renew Hp until they are dead, or just cast Tsunami after the Storm of Vengeance is over. they had to leave the area to live so they are at disadvantage to shoot from whatever range they made it to. Although more than likely there are not nearly enough left to matter.

[RickAllison]

Honestly, and it is a cheap shot, but True Polymorph/Shapechange works for the wizard gloriously. Turn into a Rakshasa and cherry-tap each enemy once. Their weapons do nothing and, when you have love-tapped as many as you wish, you Dimension Door away and run away while casting Phantom Steed. You don't Teleport away because you want them to follow you. You want them making forced march checks in pursuit and to be far away their home. Then, when they inevitably rest, so many of their forces simply don't feel any better in the morning. The army is exhausted, they have accomplished nothing, and the wizard is free to do it again. Oh, and you can't even Counterspell the dang Dimension Door or magically damage the Rakshasa in case they have casters.

Or just turn into a demilich. Fly into the army and reap the souls of the pathetic warriors with Howl. If you get low on health, drain some fools! Or an androsphinx; that third roar especially will wreck anyone close enough to shoot you.

[JackPhoenix]

Snippity snip

Or, because nobody can be bothered to actually roll 1000 attacks, you use mob rules from DMG. As they need 20 to hit, the rules say the champion gets hit once per every 20 attackers (yes, actual math doesn't work out that way, but whatever, it's much more advantageous to use mob rules than rolling it out, especially with disadvantage.). That means the 500 man (hobgoblin) army gets 25 hits (interestingly, the same number Citan reached by his mistaken calculations). The champion gets hit for 125 damage per round before he reaches melee. As there's no need to dodge, as disadvantage doesn't do anything in this case, it would take the champion 2 turns before he reaches melee range. Unfortunately, he'll be dead by then.

Well, more than anything, this demonstrates that the mob rules are... eh.

[Citan]

Disadvantage play a big role. You only have 0.25 chances to get a crit when you have Disadvantage, not 5%. So no, this part of my calculation is accurate.

Errr, right, not sure how my mind got twisted here, I mixed critical hit and critical fail. Ahem. XD
You are right, no miss in that part indeed. :)

On the rest...
1. About movement troops
You are speaking about an army that marched in an organized way. There is no reason why they wouldn't know how to actually engage while maintaining order. And there is no particular reason either to not roll Initiative as a group, because, again, this is an army, an organized group with scouts and predefined group movements.

2. About Dodging:
Hobgoblin has 18 AC. Paladin has +11. Meaning chance to hit is 70% without activating GWM, 45% chance with. If creatures Dodging, that drops to 49% and 20% chance respectively. Although I don't see why Champion would gamble on GWM when he's pretty sure to end a creature in 1-2 hits already. Still, with 4 attacks a round, its chance to kill Goblins would go from "probably 2, maybe 3 per round" to "probably 1".

3. About Shoving and Grappling: once in contact, best bet for Hobgoblins is rushing to Paladin and Shove + Grapple him. Let's say Fighter is proficient in Athletics to put all chances on his side: he has +11 to roll. Hobgoblins have 12 DEX, 13 STR, so +1 only. Obviously chances are on the side of Champion. But the other side has numbers: as a medium size creature, they can grapple Champion, in addition to shoving him. So who cares if the army loses 2, 5, 10 goblins in the process? Please display the probability calculation if you know how to do it, my maths are too far away in the past. What I'm pretty sure of though is that Paladin WILL get prone AND restrained.
By the way sorry but you are mistaken: there is no reason why only 8 would try: you know they can move AFTER trying their luck: so conservative number would be rather 16, maybe even 20.

And once he's prone, his attacks are made with disadvantage, and everyone else has advantage within 5 feet. Pushing chances of melee attackers to 10%: considering a medium size creature, and 30 feet speed, you can expect a few dozen Hobgoblins to get a better shot at Champion while everyone else is still using arrows or using Dash to create a live circular wall. Because confer previous point: there is no reason why they would stick around after trying their luck as long as they still have some speed. "Worst case", if this is REALLY a professional army, the firstcomers that don't have enough speed left could just put themselves prone and let other people walk on them: admiteddly that is pushing very far (I don't see such creatures being this dedicated honestly, but at the same time I know little around fluff). ^^ Anyways, back on tracks...
AND because there is (at least) one Hobgoblin grappling him, they can activate Martial thingy too, severely pushing their damage to your aforementioned 13 average.
So the amount of damage Champion will be dealt will be probably more about somewhere between 40 and 80 in that single turn, depending on how many Hobgoblins could reach him, try their luck and make way for others in the first (Shove+Grapple) and second phase (attacks). And that is only for melee: you could have 2/3 of the army firing while the Champion was still standing (5% chance to hit if Champion actually engaged in "making contact" turn instead of Dodgin) so 5% chance to hit, while the last third split between Grapples, Shoves, Attacks and tactical surround (1/3 of 500 is around 170 if I approximate well: take 100 of them just Dashing around to surround, you still have 70 of them for the melee part).

But there is worse: because Champion is prone, his only chances to break the condition are succeeding on a check (taking action) or killing the grappler(s). If there is only one grappler, and provided it's accepted that Champion can use his two-handed weapon normally (I mean, by RAW it perfectly can, just hinting that some DM may find it strange depending on how the Hobgoblin is supposed to be grappling, or if there are 3+ Hobgoblins grappling him), obviously his best chance is wacking away: with luck, one hit will be enough. With very bad luck (miss and poor damage roll), he may need 3 of his 4 attacks to kill it.

But there is worse: let's say there was only one grappler, and Champîon killed it: now he has to stand up, using half of his 40 feet speed. Now there is 20 left. Obviously the Hobgoblins will have created a circle around him, so he can't run away, and he can at best kill 1-2 creatures. OR, he could Dodge but this would serve no purpose. OR, he could Dash and try a high jump above one creature.

And then comes the Hobgoblins's turn again: rinse and repeat.
Any mundane martial, even this Champion, WILL go down eventually if he tries the melee way. There is just too much difference in numbers. You covered AC well, but there are many other factors. ;)