swarms

[dehro]

how does a swarm of insect work? I have read the rules a bunch of times over the years, but I still struggle to understand how to actually use them in a fight.. and since I would be the DM on this occasion, that would be poor form. How does it work with AoOs and AoE spells? do they only attack on the same square they are in without reach? how about a flock of birds, does that still count as a swarm?

[Unoriginal]

How does it work with AoOs and AoE spells?

Just like with the other kinds of creatures, there is no special rules for the swarms concerning those.



do they only attack on the same square they are in without reach?

Yes, unless they somehow have more than 0ft of reach, they have to share at least one square with the target.



how about a flock of birds, does that still count as a swarm?

You could homebrew a flock of birds as a swarm, if you want to. You could also just have several individual birds if you'd rather.

[JackPhoenix]

You could homebrew a flock of birds as a swarm, if you want to. You could also just have several individual birds if you'd rather.

Why homebrew? Swarm of ravens (murder of crows sounds cooler, though) is in the MM

[Arcturus]

Why homebrew? Swarm of ravens (murder of crows sounds cooler, though) is in the MM

Murder of Crows makes a lot more sense as a swarm as well. A raven is almost as big as a halfling. Though a swarm of halflings does seem like it should be a thing.

[Unoriginal]

Why homebrew? Swarm of ravens (murder of crows sounds cooler, though) is in the MM

True, I didn't remember that. Possibly because I don't remember seeing them in anything.

Interestingly enough the murder has a 5ft reach, as well are being pretty decently strong for their CR.


Though a swarm of halflings does seem like it should be a thing.

Warhammer has swarms of snotlings, it's pretty funny.

[Psyren]

how does a swarm of insect work? I have read the rules a bunch of times over the years, but I still struggle to understand how to actually use them in a fight.. and since I would be the DM on this occasion, that would be poor form. How does it work with AoOs and AoE spells? do they only attack on the same square they are in without reach? how about a flock of birds, does that still count as a swarm?

There's not much to understand, everything you need to know is in the current statblock.

They can occupy a creature's space (and indeed must do so to attack it), have a lot of condition immunities and physical damage resistances. Swarms have no special rules relative to area attacks in this edition. They can't make opportunity attacks since their reach is zero. You can make OAs against them, but again, their damage resistances likely come into play.

As mentioned above, there is an unkindness a swarm of ravens on MM 339 you can use to model any other bird swarm you want.

[Unoriginal]

They can't make opportunity attacks since their reach is zero.

"If you leave a hostile creature’s reach during your move, you provoke an opportunity attack."

I would say that if a swarm is occupying the same space as you, leaving said space counts as "leaving a hostile creature's reach".

IIRC the opportunity attack happens before the creature moves, timing-wise.

[Psyren]

"If you leave a hostile creature’s reach during your move, you provoke an opportunity attack."

I would say that if a swarm is occupying the same space as you, leaving said space counts as "leaving a hostile creature's reach".

IIRC the opportunity attack happens before the creature moves, timing-wise.

Hmm, I'd personally argue that being zero means you're never technically in it in the first place. Has there been a ruling on this?

[PhoenixPhyre]

Hmm, I'd personally argue that being zero means you're never technically in it in the first place. Has there been a ruling on this?

In that case, swarms would not be able to attack, because the target has to be in reach.

[Psyren]

I found the ruling in question (https://twitter.com/JeremyECrawford/status/739900185002659840) so I'll cede the point. That is definitely a change from 3.5 however.

[stoutstien]

A fun thing to do is swarms is have them occupy the space of another swarm and then have them split up as he encounter goes on

[PhoenixPhyre]

As a complete aside, the answer to "how do swarms work" is "really brutally, at least against parties lacking in strong non-physical damage." Just ask my party.

It's not my fault the level 3 wizard derped and doesn't have any damage spells (yet) other than firebolt[1], the paladin couldn't hit a darn thing (stupid dice), and the protean[2] was using the mutation granting darkvision, not the one granting an aoe acid breath. The dragon knight, I can forgive. He barely has anything natively that does non-physical damage, and his drakkon doesn't get the magic weapon effect at this level.

[1] he's got chromatic orb...but didn't have enough starting cash for the diamond component, since we started at level 3 without much extra gold. He's built as much more a utility/control wizard than a blaster.
[2] one of the two homebrew classes being playtested. A mutation-based "skirmisher" pseudo-rogue, more wilds focused than social. Can swap out mutations with actions, but has a limited number available at any given time. Mainly fights with claws (basically monk unarmed strikes, but slashing).