Inverse swarm monsters


I think this dude was an inverse swarm
Image source: Final Fantasy 7

In a swarm monster, multiple enemies are represented as a single monster mechanically. This is practical because it is easier to manage for the referee and also interesting on the player interface side because a swarm of flying demonic bells might be immune to most weapons but vulnerable to area effects and perhaps sweet singing. (I believe 3E should get credit for this innovation, though I am not sure about that.)

In a recent post, Gus catalogued a number of ways to make solo beasts more interesting and challenging. To this toolbox, I would add the inverse swarm, which is a single enemy represented mechanically by multiple monsters.

So an elder dragon might have head, body, two claws, wings, and a tail, each with a separate attack, different ACs, and its own HP total. This avoids the biggest weakness of beasts versus adventuring parties, which is the limited number of actions the monster can take (1, or maybe 3 for a claw claw bite routine) compared to the 6+ chances an adventuring party gets to take on the attack roulette wheel each round. It also allows interesting strategies, like disabling particular abilities.

The only real downside is that the referee needs to spend some thought on the monster, preferably beforehand (though it is possible to improvise a less complicated inverse swarm).


7 thoughts on “Inverse swarm monsters

  1. Faoladh

    As a point of historical interest, I think that it was either GURPS or Call of Cthulhu which first used the concept of treating a swarm of smaller creatures as one diffuse creature for rules purposes.

    1. kenco

      I think the swarm of rats and the insect swarm (technically a spell not a monster…) have a long history in D&D. The rats certainly go back to B/X (1981), probably Holmes. Pretty certain this pre-dates Call, and certainly well before GURPS.

  2. Inverse Swarm Generator

    What’s more, you can make a generator. Maybe choosing between goo, biped, quadropod, hexapod et cetera base forms, with a chance for extra limbs, heads, wings, tails, etc… Do some parts make the rest invulnerable? Provide regeneration? Stingers on the wings? Tentacles?

  3. James Young

    Oh wow, between this and 5e-style legendary actions this is a winner.
    Disabling bits of big baddie is a proper good thing and I’ve struggled to model it outside of handwavey stunt stuff before.
    I’d definitely give a dragon’s claws/ankles a high AC to make people climb the bastards.


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