D&D 5E Swarm of insects (spiders) -- How do you run this monster?

[Weiley31]

Centipedies are evil but what is more evil that is nickelipedies and what is more evil that than dimeipedies and what is more evil than than quarteripedies!

It's all over once the Tetraipedes enter the server.

 

[Weiley31]

Also, when presenting swarms of insects or spiders, always ALWAYS leave open the possibility in your description that a bug crawled into one of the PC's ears and is now laying eggs in his or her brain.

That sounds like an unfun insta kill.

 

[BookBarbarian]

That sounds like an unfun insta kill.

Oh I'd say there's some time before death.

I'd have it curable by a Greater Restoration, Regenerate, or even Remove Curse.

 

[Shiroiken]

I'm about to run Ghosts of Saltmarsh, which includes a few encounters with insect swarms (spiders). As I read the stat block, it occurs to me that I have no idea how to run this monster. Unlike a swarm of flying insects, the spiders need to crawl onto a target to attack it (I assume, because that's the only thing that makes sense). But I'm not sure how to describe this action without giving the players the impression that they're being engulfed in spiders and can't attack for fear of hurting themselves or their companions. (How the hell do you stab a spider when it's crawling on someone, anyway?)

I guess I need to make it clear to the players that the "swarm" is a monster that can be attacked, and not some sort of trap/hazard that must be dealt with creatively. But how do I do that?

The spiders will need to start climbing on the person they're attacking, but make sure to describe the players attacks as knocking the spiders off carefully, and if a 1 is rolled maybe have the character's armor/clothing nicked (no actual damage).

Also, don't forget they can climb... I had a swarm drop on a PC in the adventure, and they freaked out (both in and out of character). Something else to remember, they have an attack reach of 0, which means they only generate an attack of opportunity if you leave their space.

(Also, the swarm has 22 HP and resistance to bludgeoning, piercing, and slashing damage, which is effectively 44 HP. That's nuts for its 1/2 CR, isn't it?)

They are on the high end of the CR, but still pretty descent*. The trick is to avoid using weapon damage, and focus on spells, fire, or even acid. In one encounter, Burning Hands was used against 2 swarms to great effect (fortunately the other PCs were out of the way). Also, their damage goes way down once they're at half HP.

*You wanna see nuts for CR 1/2, check out the Shadow. This can scare characters of almost any level.

 

[MNblockhead]

That sounds like an unfun insta kill.

As @BookBarbarian said, I would treat it more like a condition. After all, in the real world, spiders, wasps, and flies that lay eggs in other creatures, the larva don't kill the hosts immediately. It is a long, slow process of being eaten up from the inside. Maybe they don't even kill you, but until they dig their way out you suffer some disadvantage. Maybe they control your brain, giving you an effect like a geas spell that compells you to put yourself in a position to be eaten by a Roc, because part of their lifecyle involves developing in a Roc's gut.

Maybe the parasites inject a chemical that make the player find some place underground to hide out in, refusing to leave until slowly eaten, allowing the larva to mature in relative safety.

Of course various restoration spells, poison remedies, and medical checks may cure the character depending on the natures of the parasite.

Lots of fun things you can do with parasites:

Zombies aren’t real—or are they? Meet 5 parasites that use mind control

It's no Halloween movie: These parasites can hijack the brains of other creatures—and make them act in horrific ways.

www.nationalgeographic.com

 

[Quickleaf]

I'm about to run Ghosts of Saltmarsh, which includes a few encounters with insect swarms (spiders). As I read the stat block, it occurs to me that I have no idea how to run this monster. Unlike a swarm of flying insects, the spiders need to crawl onto a target to attack it (I assume, because that's the only thing that makes sense). But I'm not sure how to describe this action without giving the players the impression that they're being engulfed in spiders and can't attack for fear of hurting themselves or their companions. (How the hell do you stab a spider when it's crawling on someone, anyway?)

I guess I need to make it clear to the players that the "swarm" is a monster that can be attacked, and not some sort of trap/hazard that must be dealt with creatively. But how do I do that?

Think of the swarm as being a central malign intelligence. Individual spiders may crawl up a PC's legs and bite them, but the mass of the swarm is still on the ground at their feet or on the wall by them. It's driving off the heart of the swarm that's important, not a few stray spiders. When the swarm moves (or the PC moves), describe how it's easy for the PC whose space was once occupied by the swarm to shake off any lingering spiders.

(Also, the swarm has 22 HP and resistance to bludgeoning, piercing, and slashing damage, which is effectively 44 HP. That's nuts for its 1/2 CR, isn't it?)

Not really. It's at the higher end, yeah, but several CR 1/2 monsters (e.g. Shadow and Jackalwere) have resistance to B/P/S damage, and if taken into account as doubling HP would place the Shadow at 32 HP and Jackalwere at 36 HP.

Proper response by a non-spellcasting character when dealing with a hostile swarm is not to draw your swords. Instead, it should be to get out the torches and lamp oil. Or burn some insect repellent. Or trigger a smushing block trap to drop on it. Or lead it into another monster in the dungeon.

 

[Eltab]

How would I run a swarm of spiders?
Up one wall, across the ceiling, and drop down on you via a bunch of silken threads.

 

[Eltab]

I'd have it curable by a Greater Restoration, Regenerate, or even Remove Curse.

or Thieves Tools, to pull the bug out of his ear.

Edit: typos

 

[Prakriti]

Lots of good suggestions here. I like the idea of running the encounter as more of a trap/hazard and counting any PC actions directed at the spiders as a "hit."

When I made this thread, I was pretty set on swapping out the swarm for a single giant spider, but now I think I'll stick with the swarm.

 

[tommybahama]

If you do background music or sound effects then something like this would be awesome:

Creeping Terror - Scary orchestral music