D&D 5E Help beefing up EXT encounter

[DurrandDurr]

Need to add interest to this encounter (environmental hazards or monsters). I'm using this amazing battlemap for my ruined city: Cursed City: https://www.patreon.com/posts/cursed-city-town-75329951

I have four lvl 15 players (Paladin with Pegasus, Druid, Sorcerer, and Artificer). They have plenty of mobility.

Background: Elven ruins of a Illithid/Far Realm attack. A few elves stayed behind to finish a ritual against the incursion while the city was sieged. They finished the ritual, but died in the process. Except for a few attempts, no one has entered the city in a thousand years and lived. The players want to explore this "lost" city instead of asking the Oracle I gave them a compass to find. Regardless, a journal here could provide them with good info. The vibe I'm going for is empty colony of LV-246 in ALIENS.

So far I have:

• Four Skittering Horrors (CR 15) that are burrowed (hibernating) throughout the city. Left behind from the initial siege, they awaken if there are any loud sounds, combat.
• Dragon Statue: It can shoot a cone of cold 30 ft. 6d6 damage (Unsure about what DC for Dex Save, and if I should also make it able to move from its spot and attack like a golem or remain able to attack in almost 360 degrees but can't leave it's spot.)
• Fireball Statue: Casts Fireball at air or land invaders. -- Water District Map--not linked)
• Fountain Statue: Water Tentacles (Black Tentacles reskin) --Water district map
• Arcane Lock: Main building (using Knock spell awakens Horrors)

Questions:

• How do I keep them from all just attacking from the air the whole time? (I don't know if they will, but the Horrors have no ranged attacks.)
• Or is it enough that there are four CR 15 creatures? (They've sailed through most battles, but I've had no environmental hazards in those.)
• Any Far Realm/Aberration creatures that can survive for 1000 years without food I can put in here? Intellect Devourers seem too fragile to have survived. (Illithids will appear later in the campaign--their ship here was damaged but it withdrew and crashed in the ocean.) But one Intellect Devourer would be nice because they will also show up later.
• Any other mines or traps that elves might have left that are still active?
• Any Far Realm siege weapons that might trigger?

 

[Quickleaf]

How do I keep them from all just attacking from the air the whole time? (I don't know if they will, but the Horrors have no ranged attacks.)

Their objective is exploration, right? You can't explore buildings from the air. Got to get down into them to see what's up. That's when the skittering monsters come out. Otherwise, they're keeping to the fringes – sometimes hidden, felt/heard/smelled but never directly seen until you're right on top of them.

Or is it enough that there are four CR 15 creatures? (They've sailed through most battles, but I've had no environmental hazards in those.)

That's fine. It's going to feel like a random left-over encounter. Personally, I'd want the combat to reveal more story. What aspects of your story can you use the combat against these monsters to reveal or expand on or shock your players with?

Any Far Realm/Aberration creatures that can survive for 1000 years without food I can put in here? Intellect Devourers seem too fragile to have survived. (Illithids will appear later in the campaign--their ship here was damaged but it withdrew and crashed in the ocean.) But one Intellect Devourer would be nice because they will also show up later.

Geez, just about any aberration could fit that bill. The ones I like are the fate eaters from Tome of Beasts, these psychic CR 6 worm things. Cloakers would be another fun option that you could reflavor any number of ways to reinforce your themes.

Any other mines or traps that elves might have left that are still active?

What about a Dryadspike? It's a floating wooden spiky sphere maybe about human head size and resembling a spiked seed pod, but the spikes undulate and the sphere rotates. When a creature uses telepathy or psionic powers within range of the Dryadspike, it shoots out a line to that creature which acts like the spike growth spell along that line – manifesting as spikes rupturing from the earth – and entangle on the creature. Any creature entangled by the spikes suffers 10 psychic damage any time they try to use telepathy or psionic power.

If you want to make this a trap that threatens the PCs you could have it be malfunctioning or corrupted, so maybe it's emitting psychic impressions via root spikes that it absorbed during the fall of the city.

Any Far Realm siege weapons that might trigger?

Ustilagor Temporal Bombard – it holds a larval intellect devourer (ustilagor) in temporal stasis, then when fired rapidly ages it so it becomes a young low-hp intellect devourer by the time it strikes its target.

 

[Oofta]

You can have just about any aberration you want, they can be in stasis until triggered. Constructs are always another option for this type of scenario if you don't want to focus on undead. Alhoons are undead mindflayers that could easily be the masterminds of all this. Of course there's the beholder zombies, which are quite low level CR but still have very powerful eye rays. Throw enough and you should be able to force them to the ground, especially if a couple attack first and then they see dozens slowly floating their way. Of course you could also just apply the zombie template from the DMG (chapter 9, page 282) to just about any creature. Want an undead Neothelid? Zombify it!

When it comes to countering flying you have a few options. One is to simply give monsters ranged attacks, the ability to attack or to pull the PCs down to the ground. The Skittering Horrors can paralyze, unless they have the ability to hover you fall to the ground if your speed is reduced to 0. This is a bit odd for someone benefitting from a fly spell or similar so it's kind of up to you how you want to run it, but strictly speaking if something doesn't have hover you fall when paralyzed. The other option is to just substitute the paralyze with a tractor beam type effect and pull them down. Along with this, don't have the horrors standing out in the open. Have them go under cover so the PCs have to come to them.

I also wouldn't worry too much about things surviving for a thousand years. There could be an entire twisted ecosystem here. Have trees that have become twisted with otherworldly power and throw in some treants. Have some kind of bizarre herbivores running around, deer with two heads or something that looks like a rabbit that sprouts furry spider legs and runs away. You don't have to have stats for any of these, they're just flavor text so let you imagination run wild.

When I've done things like this the city is largely a backdrop and provides flavor. The main encounters still happen in buildings and constrained places if it makes sense. In addition, I reflavor monsters all the time. If I want to use a boneclaw as an aberration, I'll just give it a different appearance and describe how it attacks differently. You don't need to run monsters exactly as written.

Good luck and if you have any more questions just ask.

 

[Baldurs_Underdark]

First of all, players might actually enjoy it if they rule supreme and the bad guys never stood much of a chance.

I am not so familiar with the LV-246, so here's just some ideas to make combat interesting but manageable for the DM:

• Air elementals (ignore the "hover" bit, and let them fly for real) - they are easy to play as DM
• Gargoyles (credible that they've been there for ages, and can fly - will be cannon fodder against lvl 15 PCs)
• Ghosts of the elves that lived there (The ghosts' possess can turn combat upside down)

 

[dvstig]

Another possibility is severely limit visibility, to 10-20ft. and make it magic fog, smoke or something else there darkvision doesn't help. Should also increase the mystery and horror factor of the place.

 

[Oofta]

Another possibility is severely limit visibility, to 10-20ft. and make it magic fog, smoke or something else there darkvision doesn't help. Should also increase the mystery and horror factor of the place.

I may have to steal this with a twist. It's not a magical fog, it's an effect of the far realms. The more you concentrate on things far away, the more twisted they become. Kind of like looking at a fun house mirror or an image with significant warping so to be unrecognizable. Stare too long at something in the distance and risk insanity.

 

[Mad_Jack]

Building on what the last two posters said, if this place was wrecked by a Far Realm incursion, maybe the entire city is suffering an "extended-hallway" effect - it's impossible to accurately tell the distance of anything farther away than X number of yards because the longer you look at it the farther away it seems... Mechanically, any ranged spell or attack suffers disadvantage if it's more than, say 30 or 60 feet away.
And like Oofta said, stare too long at anything and it starts to go all Inception on you.

 

[DurrandDurr]

Their objective is exploration, right? You can't explore buildings from the air. Got to get down into them to see what's up. That's when the skittering monsters come out. Otherwise, they're keeping to the fringes – sometimes hidden, felt/heard/smelled but never directly seen until you're right on top of them.


That's fine. It's going to feel like a random left-over encounter. Personally, I'd want the combat to reveal more story. What aspects of your story can you use the combat against these monsters to reveal or expand on or shock your players with?


Geez, just about any aberration could fit that bill. The ones I like are the fate eaters from Tome of Beasts, these psychic CR 6 worm things. Cloakers would be another fun option that you could reflavor any number of ways to reinforce your themes.


What about a Dryadspike? It's a floating wooden spiky sphere maybe about human head size and resembling a spiked seed pod, but the spikes undulate and the sphere rotates. When a creature uses telepathy or psionic powers within range of the Dryadspike, it shoots out a line to that creature which acts like the spike growth spell along that line – manifesting as spikes rupturing from the earth – and entangle on the creature. Any creature entangled by the spikes suffers 10 psychic damage any time they try to use telepathy or psionic power.

If you want to make this a trap that threatens the PCs you could have it be malfunctioning or corrupted, so maybe it's emitting psychic impressions via root spikes that it absorbed during the fall of the city.


Ustilagor Temporal Bombard – it holds a larval intellect devourer (ustilagor) in temporal stasis, then when fired rapidly ages it so it becomes a young low-hp intellect devourer by the time it strikes its target.

Some really great ideas here! I may use Fate Eaters (never heard of them before) if they seek the Oracle. (I'm already using Woe Striders--but calling then Haruspex or Clairvoyeurs--in a Shadowfell corrupted city.)
The Draydspikes are inspired. Really great for what I need.
Before I read your post, I had decided to have an alien object imbedded in the ground that delivers Intellect Devourers in stasis chambers. One of the chambers failed to open, so if they open it: surprise!
Thanks for the specifics and ideas!

 

[DurrandDurr]

Thanks for all the replies! I tend to think inside the box: trying to justify why the monsters behave the way they do rather than change them. So this helps get me out of the box. The people on this forum are always helpful!
I'll use the fog idea for sure as they enter the city to add suspense.
I should've mentioned that the BBEG is a Great Old One, so I may pocket some of these ideas for when it punches through into the material plane.

 

[Mad_Jack]

In general, whenever you want to use something that doesn't necessarily fit neatly within the "box" of your larger picture, rather than saying "that doesn't work because X...", ask yourself, "How does this element end up being somewhere it normally wouldn't be?"
Whenever there's a GOO involved, it's basically carte blanche to break the "box" into kindling and burn it.
(Using, say, Cthulhu as an example, the fact that (by Mythos lore) he's sleeping under the ocean means that you could just as easily populate an adventure where he or his machinations are the driving force with sea creatures as undead, cultists or aberrations.)