RAW/RAI of Swarms for BM Ranger

[SouthpawSoldier]

Like the title says, would it be legal (both RAW and at your table) to allow a Willard-esque BM Ranger to use a Rat Swarm (or other Swarm variety) as an Animal Companion?

RAW Requirement: Beast (check); CR 1/4 or lower (also check)...Size is the hangup. An individual rat is obviously of less than Medium Size. The Swarm as a whole is Medium sized. Can one as RAW consider a cohesive Swarm a single creature for the purpose of a BM's companion? How many individuals for the Swarm? Does one heal each animal, or is the swarm healed by recruiting additional animals? And for the kicker.....how would one convince a blacksmith to manufacture a couple dozen sets of barding for rats?

[HoarsHalberd]

RAW nothing against it. But as always, up to your DM. Don't plan anything before you ask him.

Healing, assume some "dead" ones were incapped and rest based healing is getting new ones. You might have to homebrew it.

How to persuade a blacksmith. Money.

Number of individuals: How many times larger the hit die are.

[MadBear]

how would one convince a blacksmith to manufacture a couple dozen sets of barding for rats?

Just make a persuasion check to let them know that Redwall abbey is about to be destroyed and these brave rats are the only ones who can stop the impending invasion. (Side note: A low or high enough roll should get you put in an insane asylum.).

[HoarsHalberd]

Actually, rules lawyery DMs (though why they would be when they're the one running the game) could say no as swarms are described as a beast but a "swarm of beasts" to avoid setting precedence for a druid to fit through small gaps whilst having a big hit die.

[Person_Man]

RAI I personally would not have any trouble with it as a DM, as long as there isn't some weird overpowered ability you're trying to slip past me.

For healing purposes, I'd say that your Swarm Companion can't benefit from magical healing which targets 1 creature, but is instead automatically brought back up to full hit points (or you replace your entire Swarm if need be) after a Short or Long Rest, because its easy for a bunch of bugs or rats or whatever to come out of the woodwork and join your pack.

I'd also allow you to split up your Swarm outside of combat for utility purposes, allowing them to scout a larger area in a short period of time and scout places where a larger creature may not be able to go.

I would not allow you to put barding on your Swarm to increase their AC. The low AC is the price you have to pay for having all those Resistances and Immunities, which are considerable.

[SouthpawSoldier]

Just make a persuasion check to let them know that Redwall abbey is about to be destroyed and these brave rats are the only ones who can stop the impending invasion. (Side note: A low or high enough roll should get you put in an insane asylum.).

In the original discussion, I brought up naming them; Rizzo, Splinter, Nicodemus, Jenner, Matthias, Templeton, Benjy, Frankie, Stewart, and Ralph to start with. Yes I know some are mice; unfortunately rats aren't as popular in fiction.

I just thought it would be fun, but the lists of immunities and abilities (Swarm of flying blindsight sentries?) worried me that it may be a bit OP (not sure that belongs in a discussion of the BM Ranger).

Still, it offers some fun uses and RP. Rat colony clinging to my clothes to mimic fur coat. Bats as a supply of guano for alchemical ingredient and magic component. 1984-esque interrogations. Possibilities are endless.

[Cyan Wisp]

RP-wise, a very cool idea! I can just imagine this character in battle, in camp, or trying to hide his swarm in his clothing as the party enters a city.

Just verisimilitude-wise (for what it's worth in D&D), I'm just trying to imagine how you'd control a whole pack as precisely as a single trained beast. Maybe you have a Judas rat (or raven, or bat) who is highly trained and is king/queen of the pack; the others just follow his/her lead.

[Malifice]

The sidebar for swarms in the MM suggests (or implies) that you cant.

That said, I don't see anything wrong with it. They should be balanced by CR.

Make sure its a swarm of rats, and don't forget your 1 level dip in Bard so you can play your pipes better.

[MrStabby]

I love this idea. I had never thought of it.

I think it seems legit and stylistically it seems sound.

[SouthpawSoldier]

Came up with it on my own when skimming the DMG Creature by CR/environment tables. Apparently I'm not the first to discuss it, though the few Google hits I found for "Swarm BM Ranger" didn't really detail legality or viability. Also missed the Swarm sidebar, since went straight to the Swarm of Rats entry. That sidebar is a buzzkill, though some DM's may willingly overlook it.

Looking at my in-the-works 5th level BM Ranger's Swarm of Rats:

AC: 13

HP: 49, 7d8-7 max (max for a single Rat is 3, so 49/3=16 to 17 Rats in a swarm; seems a bit small to justify the moniker)

Bite: +5 to hit, 10 (2D6+3) Damage or 6 (1D6+3) if at <50% HP

No proficient skills or saves to bump. Just the listed resistances and immunities. Would have to get DM endorsement of some method of healing; the suggestion of recruiting additional rats during rest periods seems reasonable and thematic.

Maybe an Alpha Rat (or breeding pair) that is/are individually healed and armored (pet(s) since childhood) Avoids the swarm as a whole being too tough via barding, but the Alpha(s) lack the immunities and resistances of the mass. Alpha(s) are trained, and swarm follows their lead (thanks for that idea, CW). A potentially lethal crit on the Swarm puts the Alpha(s) at risk, with disadvantage to notice the odd armored rat in the mass to prevent them being specifically targeted (doesn't apply to other Tiny creatures; easier to notice an armored individual when you're equal size). Treat the Alpha(s) as companion within a companion.

Plan wasn't so much a flute as a whistle on a thong around the neck, similar to a dog whistle.

Now, compared to the popular Giant Badger

AC 13 (base, w/out barding)

HP 20 (2d8+4 Max)

Bite: +6 to hit, 8 (1d6+4), and Claw: +6 to hit, 10 (2d4+4)

Double HP & immunities seems to heavily favor the Rat Swarm.

[Yagyujubei]

yeah but BM is one of the more underpowered archetypes anyway, so giving them a little bump by allowing swarm seems like it shouldn't be a problem in light of how amazing it could be RP wise.

[Joe the Rat]

Is it any worse than the mounted halfling shenanigans?

I'd allow it. Hell, I have a pair of thugs with raven swarms waiting in the wings to torment the party. If anyone wants to learn their trick (and switch to ranger), more power to 'em.

[Person_Man]

yeah but BM is one of the more underpowered archetypes anyway, so giving them a little bump by allowing swarm seems like it shouldn't be a problem in light of how amazing it could be RP wise.

I agree. But its also worth mentioning that BM is only underpowered if your DM enforces strict RAW, and does not allow your Companion to take Bonus Actions, Reactions, actions when you're incapacitated, use barding with Proficiency, Multiattack, and/or allow special ability DC's to scale. If the DM allows some or all of those fairly reasonable RAI accommodations, then its considerably more powerful.

[SouthpawSoldier]

So, how does this sound, folks? Obviously will tweak per DM's guidance, but could use some proofreading of language and structure before submission. Not much experience writing rules; not easy to write clear, specific rules without practice or experience. Any exploitable rules, or anything that is open to misinterpretation? Do the write-ups make sense?


AC: 13
HP: 49
STR: 9
DEX: 11
CON: 9
INT: 2
WIS: 10
CHA: 3

Resistance: Bludgeoning, Piercing, Slashing

Immune: Charmed, Frightened, Paralyzed, Petrified, Prone, Restrained, Stunned

Darkvision: 30, Passive Perception: 10

Keen Smell: Advantage on Perception (scent)

Bite: +5 Attack, 2d6+3, 1d6+3 when at <50% HP

Swarm: Can occupy another creature's space, move through Tiny openings. Cannot be targeted by spells or spell-like abilities (including magical healing) that target individual creatures.

Leaderless: If struck with Critical Hit, attempts to flee, attacking any creature or barrier that prevents escape.

Pack Recruitment: Can heal 3HP by recruiting a replacement Rat after a Short Rest, or 24HP by recruiting 8 Rats after a Long Rest (17 Rats total).



AC: 15 (Barding; Studded Leather)
HP: 3
STR: 2
DEX: 11
CON: 9
INT: 2
WIS: 10
CHA: 4

Darkvision: 30, Passive Perception: 10

Keen Smell: Advantage on Perception (scent)

Bite: +3 ATK, 4 DAM (Piercing)

Leader of the Pack: If Swarm is struck by Critical Hit, becomes incapacitated; Swarm will disperse and flee. Can be resuscitated after the encounter.

Immune: Charmed, Frightened, Paralyzed, Petrified, Prone, Restrained, Stunned; Bludgeoning, Piercing, Slashing while Swarm is at greater than 3HP. Cannot be individually targeted while part of the Swarm. If separated from the Swarm, Immunity to physical damage become standard Rat Resistance.

Tiny: Can occupy the space of another creature.


Idea is that while the Swarm is around, it takes the brunt of attacks that would otherwise harm Little Nicky. If an opponent is lucky enough the get a Crit, Nicodemus is knocked out and the swarm becomes uncontrollable. No Swarm, and Nicky is like any other individual Rat Animal Companion.

This makes the Swarm tough, but not unkillable (Crit or AoE), and Nicky even tougher, but he's no threat without the Swarm to lead.