D&D 5E Designing a fantasy army in 5th

[AriochQ]

Fantasy Army

You really need to consider what an army in your particular fantasy setting would look like. The main variable is magic. In a high magic setting, things like castles become less useful, enemies could just fly over them.

The same goes for armies. You can assume they will use whatever resources they have to the best of their ability, given they have experience to draw upon. Historical armies on the move would use pickets, vanguards, or scouts while moving. A magic based army would do the same, but would employ magic.

At the very least, they would have some sort of detect invisible going. They could employ magical, or non-magical creatures. Their level of communication could also be improved and much faster than a historical army. Specialty classes (e.g. casters) could be focused in elite units, or could be spread out among the troops.

I would really spend time considering how the army is configured and then think about what makes sense given the particular setting they are in. Once you have that figured out, it should be pretty apparent what will happen to the PC's when they try their plan.

 

[neobolts]

Other than use a mass combat system, I would focus the party on "high value targets" during the fight. The PCs become an elite strike team.

Have them disrupt the enemy supply lines, kill key enemy general and other NPCs.

Some of the "big bads" I always include in an army attack: a commander, a champion (a warrior that leads the vanguard and challenges/taunts the party), a "chaplain" (cleric boss to tie in the enemy's faith), a giant "pet" monster.

A great example of seige defense without mass combat is the Battle of Brindol in the Red Hand of Doom module. The party held choke points and skirmished in the streets with invaders.

 

[Riley37]

I suggest this:

Write three variations.

Scenario A: the mages leading the army, and the mundane officers, are treating this like a walk in the park, and have minimal precautions so far. Maybe they send scouts ahead on horseback, maybe they make sure that there are some guards awake at night, but just the bare minimum of preparation. Because, history shows us again and again, there really are people who gain command of armies without being habitually careful or foresighted.

Scenario B: the mages and the officers are taking reasonable basic precautions. They make sure that the supporting casters have a good mix of prepared spells; some with Counterspell, some with Dispel Magic, a few with Haste (with designated recipients, such as the highest-level fighters or rogues in the special forces). They do an Augury or two, daily. They cast Alarm, at least around tents for the command group. They keep some missile weapon troops on high alert, whenever they're on the move, as in, walking with bows in hand and strings already taut and arrows nocked. (I dunno that Roman legions would have ever done so, in anything less than the most hostile territory.) The army sets up camp on a Roman basis; that is, they sacrifice an hour or two of daily marching time, to set up a camp with palisades, *every time they settle in for the night*. They're careful about their food and water sources.

Scenario C: the army is VERY prepared. They have glitterdust, and they have people who are specifically tasked with contingency plans for when and where to use it. They're doing whatever they can to learn about the PCs and any other opposition. They have a rotation, in which casters burn Augury/Divination/etc. at planned intervals, for questions such as "are any hostile forces currently approaching our camp" or "are any hostile forces lurking in ambush along today's route". When they encamp, they put a ritual-cast Leomund's Tiny Hut on high ground as a guard tower, and they have sentries with telescopes peering out of the LTH, backed by the army's best sniper archers. If things go badly, they have contingency plans for withdrawing to their last relatively-safe encampment. Their forces might include Rangers trained in scouting and tracking, Druids or mages who Speak with Animals or otherwise learn what they can from local wildlife, and whatever other "dirty tricks" you can think of.

In this kind of scenario, whoever thinks more thoroughly about their options, and about countermeasures and counter-countermeasures, has a huge advantage. The PCs have... as much attention and forethought as a handful of players will put into the situation. The invading army can have a LOT more, because you can do things such as crowdsource this question. But you also have an artistic decision to make: just because you CAN have the enemy leader be a methodical and creative tactical expert... is that the NPC which is actually leading this particular army?

Keep in mind, historically, some armies have been lead by sloppy, lazy idiots. It happens.

 

[MonsterEnvy]

Other than use a mass combat system, I would focus the party on "high value targets" during the fight. The PCs become an elite strike team.

Have them disrupt the enemy supply lines, kill key enemy general and other NPCs.

Some of the "big bads" I always include in an army attack: a commander, a champion (a warrior that leads the vanguard and challenges/taunts the party), a "chaplain" (cleric boss to tie in the enemy's faith), a giant "pet" monster.

I do it in a similar way. I have

Enemy General/Army leader
2nd in command/favored commander
Elites (Essentially multiple champions of your type.)
Chaplains (like yours except I normally always have two.)
Tactician (guy or guys who do most of the planning. Tend to be wusses compared to rest of officers.)
Freaks (Officers who don't find the mold of the above and tend to be weird but important resources to the army. Giant "pet" Monster would fall under this section for me.)

For the freaks section two examples I used were a Mind Flayer and a Wight. This was back in 3.5 so they work differently now. (Well the Mind Flayer could still work the same.) Anyway the Mind Flayers job was to travel between his forces camps in order to constantly reset his psonic rewriting of the soldiers minds that prevented them from feeling fear or thoughts of disloyalty.
The Wight's job was stay at the main base of the army and turn prisoners they capture into Wights. Eventually using this Wight. They created a small army of wights who would march into battle with their forces and turn their enemies into Wights to bolster their numbers. All the Wights originating from and forced to obey the source Wight back at their base. Which is why it's not allowed to leave the main base. If it was destroyed they would lose control of all of their Wights. (My players eventually succeeded in assassinating it when the army was marching towards a major target. As a result all of the armies wights turned on their living comrades and the enemy army ripped itself apart. Reducing the enemy numbers by about 70% before they managed to destroy all the Wights.)

 

[Jester David]

The size of the army alone might prevent some of this. Finding a single person among 10,000 is hard enough, let alone at night while on the clock. An army camp would cover several thousand square feet and is really a mobile town. That's some serious investigation checks.

Even if the party is smart and manages to narrow down which tent and where, I imagine a smart wizard would deal with the situation much like modern leaders deal with snipers and assassins: body doubles. There might be a magical clone or a doppelganger or a polymorphed figure or something worse (a homunculus designed to look like the wizard that can be detonated at range to discourage kidnapping).

That's assuming the wizard even draws attention by dressing different and having a larger/more opulent tent. In much the same way Lt. Dan don't want to be saluted, the wizard might want to be unrecognisable from a distance. That's barring magical illusions to disguise the camp and its details.

 

[Riley37]

See also: Gaius Mucius, who infiltrated an army camp besieging Rome, attempted to kill the enemy king, and instead killed the king's scribe, who looked equally well-dressed.

Seeming is a 5th level illusion that works like Disguise Self on an *unlimited* number of subjects, within 30' range.
It lasts 8 hours, no concentration. If the army has a 10th-level wizard, this might be worth a 5th-level spell slot, situationally. If you know there's someone trying to infiltrate your camp, this produces a LOT of doubles. Alternatively, if you're trying to infiltrate an enemy camp, this gives a LOT of infiltrators a basic disguise.

(If our heroes have *already* infiltrated the enemy camp, and a lot of people gather within 30' of one wizard, and the wizard starts to cast Seeming: then that's a high-value target, especially for an AoE attack.)

Shortly before a battle, Seeming could make all the army's wizards look like they're wearing the basic soldier armored outfit, making them harder to pick out except when they're actually casting. Alternatively, it could make a platoon of ordinary soldiers look like mind flayers, as a bluff unit to break enemy morale.

If you DO have an allied band of mind flayers, you could use Seeming to disguise them as civilian refugees, or some unit that's allied to the town, or the PCs; while in the same casting, you disguise a dozen ordinary soldiers as mind flayers. The bogus mind flayers stage a bluff attack in one location, and then your real mind flayers attack somewhere else.

Perhaps the invading army has a population of "camp followers". Threescore of those camp followers sneak away from the army camp, and show up at the city gates begging for refuge. Many of them, however, are something else (mind flayers, asassins, etc.), under the influence of Seeming. Say it takes them two hours, after the casting, to make their way to Target City's front gate. They've then got six more hours to make their way through town to high-value targets, before Seeming wears off. Trojan horse tactics for the win!

 

[Reynard]

My party knows a small army is coming to their town, led by mages who want to perform some awful ritual there. The PCs are trying to stop them before they arrive.

I want this to feel daunting, so how does a fantasy army deal with PC tactics and abilities? My party is 7th level, with a warlock, a fighter, a bard grappler, a paladin, and an abjurer.

Right now the party's plan is to set up a few hundred feet from the road the army is taking, and when they're in sight, cast improved invisibility, silence, and fly on the party grappler. She'll fly over the column, grab the mage leader, and fly him back to camp. Commense murdering.

Then the party flees. One PC activates a stone of summoning earth elementals in order to slow pursuit. The terrain is rough, and it's the party's home turf, so they should be able to outpace soldiers on foot.

If that doesn't break the army's morale (it won't), they'll swing back the next day, and reuse the earth elemental to burrow under the army, then come up and break wagons. And they have befriended a couple pixies who can go in while the camp sleeps to set things in fire and generally cause a ruckus and keep them from resting. Plus a middle of the night fireball from the sky.

They're using guerilla tactics, and have magic. How does a fantasy military respond and defend itself? My ideas in the next post.

Some questions:

How big is the "small" army? In the dark ages, armies could be as few as a few dozen people while in both earlier and later periods armies were often numbered in the thousands. If there are enough soldiers to fully surround the PCs, they are going to be in trouble. If 8 figures can get around the PCs, that is 4 attacks with advantage per round as they aid one another.

What level are the mage leaders? How many of them are there? If they are the "mage" enemies in the MM/basic rules, they are not good for much outside combat, but if they are actual classes wizards with spell books and rituals, the PCs should have a much tougher time of it.

How much time do the PCs have before the army arrives at the town? Being able to hit and run the invaders for a week is different than having one shot at it.

And finally, what are the stakes?If the PCs fail does everyone die and/or become zombies in the evil mage army? Are the PCs heroes, or in it for the money? Who will cut and run first, the PCs or the invaders?

 

[Quartz]

In 5E mooks are a serious threat to even the highest-level characters.

Any noble worth their salt is going to have their retinue with them, which will include a mage and a cleric and a fighter, plus men-at-arms. Of course, the noble may well be a mage. Or a warlock.

 

[Bupp]

I'm seeing an awful lot of 19th-20th C assertions that don't really fit medieval troop standards.

You bring up some great points about medieval warfare, but the magic level of the game world has a huge effect on this. While the weapons and armor look like medieval weapons, magic is indistinguishable from science and can make 19th and 20th century tactics the best way to proceed.

 

[bedir than]

You bring up some great points about medieval warfare, but the magic level of the game world has a huge effect on this. While the weapons and armor look like medieval weapons, magic is indistinguishable from science and can make 19th and 20th century tactics the best way to proceed.

Which came first the tech/magic or the tactics?