I have an issue with swarms

[CleverNickName]

Back in 2006, I modified the breath weapon of a dragon so that instead of breathing a cloud of gas, it spat out a Large swarm of poisonous insects.

Over a decade later, my players still talk about that encounter.

 

[robus]

Oh, that's easy. A pack is organized in its actions. A pack of wolves is purposefully acting to take advantage of how many of them there are. They are thinking about their actions, and actively cooperating.

Swarms of bees, bats, and zombies don't use tactics at all - they don't have sufficient brains for it, nor modes of communication detailed enough to support it. They are just a group of individuals moving together, but not *working* together.

Yeah - but the pack is a small number of smart creatures and this is a large number of dumb creatures. In my imagination the result is the same (they're gonna git ya! )

 

[Shiroiken]

I guess the big thing for me is the lack of advantage on attacks. Why should a pack get it and not a swarm?

Because pack tactics represents the ability of intelligent beings to take advantage of each other. A swarm is just a mass of critters that may or may not be working together, depending on the swarm. A swarm of bats is just a bunch of bats flying together and biting anything that moves, while a swarm of kobolds would be working together (gaining advantage).

 

[MarkB]

Maybe change it up so that instead of the swarm attacking on its turn, engulfed creatures take damage at the start of their turn, Dex save for half damage. It does a good job of making armour no use against critters which can crawl inside it, and most creatures will be unable to completely avoid the damage.

That still leaves the swarm in need of actions to take on its turn.

 

[UngeheuerLich]

I think the swarms are missing swarm resistances from 4e.
Area attacks should do more damage than single target attacks. I don't know how to write it up in 5e.
Probably resisance to piercing from nonmagical weapons. Vulnerability: attacks that target all creatures in a certain area of effect.
Maybe you need to stat it more loosely:
The DM might decide if a certain attack is especially ineffective or effective against a particularly swarm.
Depending on this decision he might grant immunity, resistance, vulnerability or even have the swarm being instantly killed by the attack.
Most swarms are made up of hundreds of tiny creatures with a single hp each.
A dagger might deal no damage. A swing with a longsword could be resisted. A fireball could deal double damage (the swarm might clump up to protect the creatures within) and a cloud of poisenous gas might instantly kill every single creature of a swarm.

 

[Cap'n Kobold]

It seems to me that a swarm should at least have something akin to pack tactics, i.e. advantage on their attacks (because of the sheer number, the odds must be ever in their favor?!) and I would even hazard that they should have multi-attack (at least while above 50% HP).

Their sheer number is already being accounted for in their high attack bonus and damage compared with the base creature.

I don't think that multiattack is necessary: their attack is already considered to consist of many minor attacks.
You could change their attack action to affect all creatures in their space, but the effective difference in most situations would be little.

If you want to make a swarm more dangerous, increase its attack and damage bonus, representing more creatures in it, or it consisting of more dangerous creatures.

Also bear in mind that an actual 'swarm' of bats for example might be represented by several of these swarm statblocks moving together.

 

[Stalker0]

If you want to make swarms stronger no problem, but honestly they seem pretty damn strong to me.

Consider that a CR 1 creature is 4 of the ones you mentioned, that's effectively 66-88 hp worth of monster (assuming you are not littered with elemental damage that can bypass their resistances), doing 10-20 damage a round.

I think it models the notion that swarms do small amounts of damage but they are so hard to get rid of, and they just keep coming and coming and coming.

If you want to make them more "interesting" I don't think advantage on attack rolls is the way to go. If you just want to make them tougher just add a +1/+2 to attacks and call it a day. But interesting I think they would need to inflict a condition, like blindness in the area or something because no one can see anything in the swarm.

 

[jayoungr]

I think the swarms are missing swarm resistances from 4e.

Don't keep us in suspense; what are those?

 

[5ekyu]

Personally, what I want out of swarms us high durability except against area attacks with high probability of doing light damage.

To me they fill the role of "mobile hazard" more than adversary.

 

[UngeheuerLich]

Don't keep us in suspense; what are those?

Swarm: A swarm is considered a single monster even though it is composed of several Tiny creatures. Most single swarms are Medium, but some can be larger.
A swarm takes half damage from melee and ranged attacks. It is vulnerable to close and area attacks, as indicated in the monster’s stat block.
A swarm is immune to forced movement (pull, push, and slide) effects from melee and ranged attacks. Close or area attacks that impose forced movement affect the swarm normally.
A swarm can enter or move through an enemy’s space; this movement does not provoke opportunity attacks. An enemy can enter a space occupied by a swarm, but the space occupied by the swarm is considered difficult terrain, and doing so provokes an opportunity attack.
A swarm can squeeze through any opening large enough to accommodate even one of its constituent creatures. For example, a swarm of bats can squeeze through any opening large enough for one of the bats to squeeze through. See the Player’s Handbook for squeezing

I highlighted some parts:
Bold: what I was referring to.
Bold and underlined: what I forgot
Underlined: how you interact with swarms

I liked those rules.