D&D 5E Swarms in 5E

[Will Doyle]

Swarms don't seem to be included in the latest playtest package. Do any of the recent published adventures feature them?

If not, how would you create a swarm in 5E?

(apologies if this has been covered already)

 

[Li Shenron]

I really don't know, but I think Mearls mentioned a couple of months ago, that they are planning to include a rules "module" (whatever that means in this case) for running groups of monsters quickly at once, which sounds a bit like swarm rules although the size might be smaller.

I just wanted to say that unfortunately I don't think this will really make the 3 core books, but otherwise it would be one of the most useful additions IMHO, much more useful that thorough mass battle rules.

 

[jamesmanhattan]

I haven't seen any and I think I've read all of D&D Next material so far.
The closest they had were the 12 Cave Rats in the first playtest of Keep on the Borderlands.

If you go full 4E style.
Swarms do automatic damage to every creature that ends its turn in its space.
On the swarm's turn it gets an attack vs. a single target.
Immune forced movement, half damage from all sources, except damage that is from an Area of Effect, then they take double damage. Cannot be knocked prone, cannot be restrained, can squeeze through small opening that are big enough for a single member of the swarm. Most would be immune to charmed, frightened, stunned, and paralyzed.

I made this swarm, but it doesn't follow the above, because I thought letting it attack only on its own turn simplifies things.

[h=2]Mosquito Swarm[/h]Large vermin (Swarm)
Armor Class 14
Hit Points 31 (7d8)
Immunities
Speed 40 ft.
Senses darkvision 60ft.
Str 1 (-5) Dex 13 (1) Con 10 (0)
Int 1 (-5) Wis 12 (1) Cha 9 (-1)
Alignment unaligned
Languages --

Traits_________________________________
Swarm Traits: The swarm can enter enemy creatures spaces and enemies can enter its space. Resistance to bludgeoning, piercing, and slashing damage. Resistance to spells that have a single target. Vulnerable to spells that effect an area. Immune to forced movement except from area spells and cannot be knocked prone or be restrained.

Mindless: Immune to charmed, frightened, stunned, paralyzed.

Actions________________________________
Swarm Attack: +5 to hit (reach 5 ft.; all creatures in range). Hit: 7 (1d6+3) piercing damage and the target takes 3 damage at the start of each of its turns as it bleeds. If someone spends an action to swat the attached mosquitos, the bleeding stops and the effect ends.



Encounter Building___________________
Level 3 XP 250

 

[Plaguescarred]

how would you create a swarm in 5E?

Like jamesmanhattan! I like 4E's style better

 

[Will Doyle]

Good work, jamesmanhattan. I agree there's a lot to like about the 4e method.

 

[Dausuul]

I think a swarm is better modeled as a terrain hazard instead of a monster. Something like this (just a very rough sketch):

Wasp Swarm (Hazard): Creatures in a wasp swarm take 1d6 poison damage* per round from the stings. Those wearing heavy armor have resistance to this damage. Spellcasting requires a DC 12 Wisdom check to maintain concentration; failure means the spell fizzles but the spell slot is not lost. Damaging area effects destroy the swarm within the area, and strong wind can disperse it.

The focus when dealing with a swarm is more on getting to a place of safety rather than trying to slaughter all five zillion bugs. If the party has a wizard with sufficiently large blasting spells, of course, the swarm can be got rid of, but is it worth it to expend a 3rd-level spell slot? Maybe, maybe not--depends on the situation. And if the wizard is already caught in the swarm, things get pretty dicey.

[SIZE=-2]*Yeah, I know, this contradicts my desire in another thread to not have poison do simple damage. This is one of the few cases where I'd go against that.[/SIZE]

 

[Plaguescarred]

Another way to handle it could be to have a Swarm or Mob template that can be tacked on top of any existing monsters easily, giving it different or complimentary HP, AC, Resistance and abilities. Here is a rough draft of what it could look like;

Swarm Template
AC +2 AC
Hit Points x5
Ability Score +5
Saving Throws +3
Reach +5
Attack +3
Damage x2
Skills perception +3, survival +3, intimidation +3
TRAITS
Deconcentrating: When a swarm damages a creature that is concentrating on a spell, it makes it saving throw with disadvantage to maintain concentration.
Damage Resistance: A swarm is resistant to bludgeoning, slashing and piercing damage
Double Action: At the start of combat, the swarm makes two initiative checks and takes a turn on each Initiative counts. The swarm has a full set of actions on each of these turns, and its ability to take an reaction or bonus action refreshes on each turn.
Fluid: A swarm can move into the space of creature of any size and end its turn there.
Shove: A swarm can use Knock Down against a target it hits as a bonus action.
Steady: Swarm cannot be knocked prone, grappled, or bull rushed.
Vulnerability: A swarm is vulnerable to area of effect spells or similar attacks hitting large area.
ACTIONS
Trample: The swarm target a point in space. Each creature within 5 feet of that point are subject to a knock down. Targets have disadvantage while the swarm has advantage on the check. If successful, the target is eighter knocked prone or pushed back 10 feet.
REACTION
Shake it off: The swarm automatically end one effect on it or succeed on a saving throw as a reaction.
ENCOUNTER BUILDING
Level +5 XP x5

A swarm is a collection of 4+ (up to thousands) tiny, small, medium or larger creatures that acts as a single creature. It has the same type, alignment, sense, language, speed and movement mode as the creature, while other characteristics changes. A swarm has a single pool of Hit Dice and hit points, a single initiative modifier, speed, and Armor Class and makes saving throws as a single creature. A swarm occupies spaces according to its size (large, huge or gargantua) and has a reach of 10 feet or more, depending on its size and the reach the creature has. Finally a swarm can squeeze through space large enough for a single creature of its kind to pass through.

 

[pemerton]

I think a swarm is better modeled as a terrain hazard instead of a monster.

<snip>

The focus when dealing with a swarm is more on getting to a place of safety rather than trying to slaughter all five zillion bugs.

In my 4e game I've used swarm mechanics to handle hordes of vrocks and other demons, packs of hyenas, and hogbolgins phalanxes, among other things. I don't think these are better modelled as terrain hazards.

 

[Dausuul]

In my 4e game I've used swarm mechanics to handle hordes of vrocks and other demons, packs of hyenas, and hogbolgins phalanxes, among other things. I don't think these are better modelled as terrain hazards.

If you have so many hobgoblins that the fighter could kill five of them a round all day long and still not make a dent in their numbers? I would absolutely model that as a terrain hazard. I'm thinking "middle of an immense hobgoblin army, tens of thousands strong." You can clear out a patch of them for a round or so by dropping a fireball, but you aren't going to kill the whole thing.

If it is feasible to slaughter them one at a time, that isn't what I would consider a swarm.

 

[pemerton]

If you have so many hobgoblins that the fighter could kill five of them a round all day long and still not make a dent in their numbers? I would absolutely model that as a terrain hazard. I'm thinking "middle of an immense hobgoblin army, tens of thousands strong." You can clear out a patch of them for a round or so by dropping a fireball, but you aren't going to kill the whole thing.

If it is feasible to slaughter them one at a time, that isn't what I would consider a swarm.

I tended to envisage the phalanxes in question as containing 20 to 50 hobgoblins, depending on size (huge or gargantuan). When I used them, they could regen hp by soaking a nearby hobgoblin minion; I know others have used an approach where on its "death" the swarm triggers the appearance of a handful of minions in its space.

The benefit of using a swarm rather than 20 to 50 hobgoblin minions is that it makes managing the round, modelling force multiplier effects, etc much easier. For instance, I can just give the phalanx a "Phalanx rush" power to enable it to make a Reach 3 close blast attack with push that also lets it shift up to 3 sq into the area of the blast. This is much easier to adjudicate than rolling 20 hobgoblin attacks, deciding which ones "aid another", etc etc.

I know that D&Dnext eliminates some of the reasons for not using minions in these cases via bounded accuracy; but the issue of 10s of NPC actions, force multiplier issues and the like are still in play.

When the "minions" would be mechanically more complex, like vrocks, the use of a swarm as the relevant mechanic becomes even more attractive.