Doubled Creature Types

Alternative title: Are we the monsters?

I had a neat idea about D&D 5e, so I've decided to make a short article about it.

Intro

What creature types can you find naturally on the Material Plane? For the sake of clarity, I would say that a creature type naturally on a plane is a creature type that's integrated within the plane's ecosystem on a long-term scale. This is not a trick question, let's just go through them:

• Beast
• Dragon
• Giant
• Humanoid
• Monstrosity
• Ooze
• Plant

Mini-rant: Giant is just a Large or larger humanoid, it shouldn't be a creature type because it's more of a size category.

I could in theory add more creature types, but these will suffice for now. Now try to tell me, what creature types can you find naturally on the Upper Planes? As far as I am aware, just celestial. What creature types can you find naturally on the Lower Planes? Fiend, maybe one or two extras.

What if there was a way to introduce a bit more variety to the various planes of existence? Let's think through this thought experiment together, and make up a system of Doubled Creature Types.

Finding an art to represent the idea of a double creature type was hard enough, so I'm gonna just go with this art, call it a "fiend construct", and call it a day. ... Addae. That's not a bad name actually.
Arcane Construct III, by CaconymDesign

Doubled Creature Types

Let us begin this journey by splitting the creature types into two halves: General, and planar.

• General creature types include beast, construct, dragon, humanoid, ooze, plant, and null (more on that later).
• The planar creature types include aberration, celestial, elemental, fey, fiend, monstrosity, undead.

(I left out giant because of my mini-rant above, feel free to put it into either category.)

Now, each creature gets assigned two creature types. In most cases, one should come from the general, and one from the planar half. Understandably, which types go where is up to everyone, but that doesn't matter.

The planar creature type determines the plane of the creature's origin. The general creature type determines its function within the ecosystem of the plane. Plants are there for the herbivores to consume, oozes consume the corpses, humanoids make civilizations, etc.

So what does this give us? More variety to all of our planes of existence where we apply these, of course! Why restrict yourself to just fey, when you could have fey beasts like talking wolves or sacred deer, fey plants who can talk to you and bind you in its roots, fey oozes that glitter or something, and other stuff. How about a corrupted bear turning into an aberration beast? A constructed celestial? A fiendish dragon? All these and so much more are suddenly open to us!

What does that make our player characters though? What is their planar creature type? Well... monstrosity is the best fit. Monstrosity covers anything that's on the Material Plane (as far as I can remember) that isn't a beast or a humanoid or anything else like that. So every human, elf, or other humanoid race has a creature type of monstrosity humanoid. Every beast of the Material Plane has a type of monstrosity beast.

What does that make the previous monstrosities, like owlbears or medusae? Monstrosity null, or simply monstrosity. Null is a simple creature type add-on that you can add on top of the planar type to make something that's just... too generic to use two creature types (unless you want to experiment a little, making medusa a humanoid or owlbear a beast).

Could there be a creature with two general creature types? Yes, for example, a wolf overgrown by plants could be one. Could there be a creature with two planar creature types? Yes, for example, the elemental titans could be both elementals and giants.

What about stuff like charm person or Wildshape? Do they now work on all these new creature types? Up to you. If you want them to work, go right ahead and experiment! If you don't want them to work with them, make up a houserule along with these that reads "whenever the rules say something affects a humanoid, it affects a monstrosity humanoid unless I say otherwise", and analogous for other creature types you're worried about.

So there it is. A short demo of an idea, without a proof of concept. I'll probably include them in some of my future brews, along with a write-up as to how they should be handled and which of the creature types is the "dominant" one. I feel like I could make a booklet on planes now, except I don't have much time, energy, attention, and ideas for that kind of stuff. I got some ideas for it, don't get me wrong. It would be a cosmology of my own, possibly similar to the one I've presented on this blog previously, or maybe a new one. It definitely wouldn't be a carbon copy of the Great Wheel, at best I'd merge some of the planes together to get the essence of all the interesting things in there. But any of that is a promise I can't make, I already have so many other ideas I could work on, and yet I feel like these days I have less and less time to work on them.