D&D 5E Suggest the enemy for my 5E war campaign?

[OGIHR]

I've been thinking about running D&D again, at my local gaming store. But my work schedule is 12hr shifts on a two-week cycle, so I'd only be able to run it every other week. I therefore need a campaign premise which allows for the inevitable random attendance by players who make other plans between sessions. And the best solution I have at hand is to frame their missions as discrete tactical engagements (which can be completed in a single session) rather than broad exploratory delves into the unknown.

So I'm planning a war campaign, with the PCs cast in the role of an elite team possessing unique tactical skills (by virtue of having PHB classes), who are frequently sent unsupported into enemy territory for surgical strikes intended to tip the momentum of the war in their nation's favor. 

Characters with the Soldier Background would obviously be properly military in their training, while those of other Backgrounds would be people who developed extraordinary skills in other walks of life, then answered the call to service when asked. 

And I want there to be an obvious moral imperative for the PCs to take up arms against the enemy, without either irony or any hint of a plot twist subverting that belief. The villains should genuinely be villains, so the heroes can simply be heroes. However...

I have no bleeping clue what I should make into the enemy whom the PCs' nation is at war against. 

I know that I want villains rather than monsters; instead of their enemy being goblins or drow or any other breed of hideous creatures which are always bad guys because the traditional tradition of traditional traditionalism says they're always bad guys, they should be PEOPLE who are up to evil badness which must be stopped through military action. 

And I know that I don't want to be tied down to any published campaign setting, so that I don't have to invest the time to read extra books in order to understand a PC's intended backstory, nor constantly come up with reasons why the various signature-character archmages are conspicuously uninvolved in the international crisis of my campaign premise. 

But that's all I know. 

All suggestions are welcomed.

 

[Tales and Chronicles]

What if the Elves, after many centuries of quiet retreat from the Prime to the Feywild decided that enough is enough and they wanted their old world back?Or have the Feylords declare a the first Wild Hunt(elvish crusade) against the Drow in a thousand years, and your country is caught in the crossfire. Its harder to fight back the enemy when they can emerge from any old and forgotten ruins in the land that in reality are fey-portals to the Feywild. Elves arent usually seen as evil so having them as the enemy will have an effect on your party, that's for sure. You can look online for the scenario of the old PS3 game ''Valkyria Chronicle'' where you play as a militia from a small country caught between two empires at war, this should be good with your idea of a small company doing hit-and-runs against an overwhelming foe.

 

[Tormyr]

The campaign guide for 5e War of the Burning Sky should be coming out within a week or two. It contains a warfare supplement that [MENTION=1]Morrus[/MENTION] created for the 3.5 version. The encounters are set around specific tasks the PCs can complete that influence the battle as a whole such as taking a strategic point, assassinating a high-level enemy official, defending against an enemy surge, etc.

 

[ArchfiendBobbie]

Make it a nation of undead. The undead are running out of food and there's this nice nation composed entirely of food next door...

 

[Satyrn]

I know that I want villains rather than monsters; instead of their enemy being goblins. . .

I was gonna suggest hobgoblins as the obvious militarized monster, but nevermind that.


What if you go with a Star Wars idea: An evil empire run by an evil wizard, with well trained professional soldiers trampling over the rights and property of all the good folk of the land.

Oh, and make some of the storm troopers - the expendable basic grunts anyway - undead, as @ArchfiendBobbie suggests!

 

[77IM]

It's always fun to make things personal, and the best personal motivation I've found is REVENGE. So who-ever this enemy is, they've got a grudge against the PCs' kingdom, and the PCs have a grudge against them.

One thing I really liked about Princes of the Apocalypse is that the elemental cultists were constantly screwing up the weather, and (SPOILER) occasionally nuking towns. This really pissed off my players, in a good way. So make sure your enemy force isn't confined to some static "war front" off in the distance; give them the ability to strike deep into allied territory to cause chaos and terror.

Underdark villains seem the best for this. First, there are a lot of "fallen empires" down there who are eager for revenge upon the surface world -- the drow, the mind-flayers, and the aboleths all crave vengeance, so what if they teamed up? Let's make them allies with the yuan-ti for good measure!

The other nice thing is that the Underdark could have entrances to the surface world anywhere, including behind friendly lines. So even though the war is happening Over There, in a surface kingdom overrun by illithids, it's still possible that a drow raiding party popped up and killed a PC's whole family during their backstory.

PLOT TWIST: The driving force orchestrating the war -- the Main Villain, or BBEG if you prefer -- is none other than the rightful ruler of the PCs' kingdom! He or she was deposed and murdered, and has returned as a revenant who is literally unkillable until they ascend the throne. So the PCs will need to find another way to deal with the villain than simply attacking them! Plus this gives the villain lots of motivation, and opportunity to intersect with PCs in their backstories.

 

[aco175]

If you are running something at the FLGS for players of various play experiencing I would want to keep things more simple for myself. A series of small modules that can be played in 1 sitting with semi-random people needs a more open-ended plot with war in the background. The PCs may never get to the front lines and stage a massive assault or be cooped up in Helm's Deep before the onslaught of orcs, but that takes play around them. You also need an enemy that can span several levels and still be a threat. Also, something that can have lots of pets, and monsters with them.

I would go with kuo-toa. I posted a module on DMsGuild having them in it. I had PCs that were 10th level, so most of the threats were the leaders of the kuo-toa and things like giant aligators. There are several new types of kuo-toa that can be used and modified to meet your needs. With kuo-toa as your primary threat you can have them pop up anywhere from underground. The front line is off there somewhere but the PCs are needed at the old temple where wounded are healing or in the sewers of town where some have been spotted. Some missions go underground to take out a leader type or intercept diplomatic missions to lizardmen or something. I had fun with them as a end of campaign monster.

 

[Satyrn]

Oh, and make some of the storm troopers - the expendable basic grunts anyway - undead, as @ArchfiendBobbie suggests!

Thinking about this slightly longer, I have a cool idea. The storm troopers don't start undead. Rather, after a battle, the empire's necromancers roam the battlefield "salvaging" what members of their army they can. So as the war drags on, the number of undead in their ranks increase.

And this is why they all wear helmets - so they won't be quite so weirded out when they have to fight alongside their now undead friends.

 

[lowkey13]

*Deleted by user*

 

[Tormyr]

Enemies?

1. Paladins.
2. Gnomes.
3. Gnomish paladins.
4. Flumphs.
5. Gnomish paladins riding flumphs, using rapiers as lances.

Nightmares fuel, man. Nightmare fuel.

Flumphs are the new Nightmares.