D&D General what is it that make certain monsters of certain categories?

[Mind of tempest]

You probably start off with an alchemy lab, a small library of magical books, a pentagram and a few years of spare time.

funny but I must ask do you have a more serious answer?

 

[Baldurs_Underdark]

funny but I must ask do you have a more serious answer?

Sorry, but no. It makes little sense to me. I guess that monstrosities may be a little closer to beasts compared to aberrations (the same point was made before in this thread), but IMHO there is no clear line that can be drawn between the two.

Here's a list of aberrations and monstrosities that in my opinion at least graphically look alike. (They may have quite different abilities - I just looked at pictures).

Aberration	Monstrosity
Aboleth	Kraken
Chuul	Ankheg
Carrion Crawler	Grick
Choker	Ettercap

So, why have aberrations?
It could have just as easily been argued that [monstrosities+aberrations] are all one and the same type of creature. But that makes that type maybe too large of a group. Then every Ranger is going to pick the [monstrosities+aberrations] type as their favored enemy. And everyone will make their Forbiddance stop at least the [monstrosities+aberrations] type. Splitting it into two forces people to make some strategic decisions.

 

[Mind of tempest]

Sorry, but no. It makes little sense to me. I guess that monstrosities may be a little closer to beasts compared to aberrations (the same point was made before in this thread), but IMHO there is no clear line that can be drawn between the two.

Here's a list of aberrations and monstrosities that in my opinion at least graphically look alike. (They may have quite different abilities - I just looked at pictures).

Aberration	Monstrosity
Aboleth	Kraken
Chuul	Ankheg
Carrion Crawler	Grick
Choker	Ettercap

So, why have aberrations?
It could have just as easily been argued that [monstrosities+aberrations] are all one and the same type of creature. But that makes that type maybe too large of a group. Then every Ranger is going to pick the [monstrosities+aberrations] type as their favored enemy. And everyone will make their Forbiddance stop at least the [monstrosities+aberrations] type. Splitting it into two forces people to make some strategic decisions.

I am trying to find the qualities that make aberrations somehow different to monstrosities.

 

[Lyxen]

Honestly, why does it have to be a quality, since by definition, monstrosities is just the category for creatures not fitting in other types, and aberrations have an alienness and/ord a link with the fat realm ?

 

[Mind of tempest]

Honestly, why does it have to be a quality, since by definition, monstrosities is just the category for creatures not fitting in other types, and aberrations have an alienness and/ord a link with the fat realm ?

I want to make aberrations if I failed to make them right I just get a monstrosity it is a goal-based question.
if I know my parameters then I can make things properly.

 

[Willie the Duck]

yes, I do know the categories are arbitrary but so is most things in this world so that does not matter?

Except it does matter as understanding how this came about is informative. The categories came to be during the development of 3e, and did so because each of these categories would inform qualities such as number sides to a creature's Hit Dice, their attack progression, skill points, and at what saves they were naturally good. Before that point, creature types/how they related to each other was much more of a 'tag' or 'flag' type scenario (and often an inherently tautological one) -- all creatures affected by a 1e ranger's bonus against giant-type creatures (list included in ranger description) must therefore be 'giant type,' all creatures getting the increased bonus against them from a 'sword +1, +3 vs. ____' must be of that type (and again the sword or monster listings themselves better let you know, or else you will have arguments over whether jackelweres were lycanthropes and if wyverns were dragons).

What this means is that there was an already existing set of creatures developed over ~30 years of proto-D&D and TSR-era D&D that then got retroactively forced into these broad categories (and also that you couldn't just say, 'well, this one doesn't really fit any of the categories, so we'll leave it as an outlier,' since that would fail to provide basic information needed to fill in the creature's basic stats). Almost inherently, there were going to be edge cases where something could have gone in one or the other category (leaving after-the-fact delineation of what makes one qualify for one or the other category murky), as well as one or more 'junk drawer' categories to house all the creatures that just don't fit anywhere else.

I am trying to find the qualities that make aberrations somehow different to monstrosities.

I think you're going to be somewhat disappointed. As others have said, aberrations kinda/sorta are defined by their alien-ness, and that's a pretty nebulous concept (especially when discussing basic biology as much as mindset). It doesn't help that some of our most iconic conceptions of something being 'alien' are, respectively, an anthropomorphized octopi (real creature), and person in black spandex with a phallic head crest and extra mouth within their mouth (all real parts of creatures), and bodybuilders in fishnets with mandibles (all parts of real creatures). When you get to 'truly' alien things, it tends to become 'made of ____' (stone, goo, motes of light, multiple constituent beings) creatures that usually end up in the elemental, celestial, ooze, or similar groupings.

 

[Voadam]

bodybuilders in fishnets with mandibles

?

I'd say umber hulks but the fishnets do not seem to apply.

Edit.

Never mind, I followed the links and saw Predator.

I had thought you were saying illithids when you meant Cthulhu.

Deep Sea stuff is a decent inspiration point for alien that works biologically.

 

[Fifinjir]

Shadowfell entities like sorrowsworn are also often listed as monstrosities, meaning they aren’t considered “extraplanar” by the rules like fey are.

 

[EzekielRaiden]

"Aberration" usually refers to what 4e would call "creatures of the Far Realm": beings from outside of reality that are antithetical to the "natural" laws of physics. These beings tend to be very dangerous and malevolent.

"Monstrosity," an invention of 5e, seems to be a catch-all term for stuff that did not evolve naturally, but which is otherwise a relatively natural creature. As mentioned above, this would include things like owlbears and manticores. Creatures that are strange amalgams of other beings, or in some other way created unnaturally from natural creatures or materials. They also tend to be a lot less outright malevolent.

"Dragon," "giant," "fey," "fiend," and a number of other categories seem to be much more like what we would normally use species/family categories as. That is, they're things that have a fundamental nature or essence in common, one that magic can detect or affect in some way.

 

[el-remmen]

why are some monsters aberrations and other monstrosities what is the common link for those categories over the years?

Back when I still had rangers using Favored Enemy ability I ended up combining monstrosities and aberrations because both were so infrequently encountered on their own that I didn't think it'd ruin anything and it didn't. That said, eventually I replaced it with an ability called "Hunter's Vision" that is more based on being a good hunter of foes with increased ability for creatures native to the ranger's favored terrain.