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Aberrations 5e

Aberrations 5e

It is fair to say that, compared to our world, most DnD settings will be strange and alien. That is the fun of why we play, after all. No one wants to roll up a character and then spend their day working in an office, shopping on the way home, cooking, and then crashing out on the sofa watching Netflix.

The sheer weirdness and unfamiliarity of the worlds we find ourselves in are a natural attraction.

We find our alter-ego character pitted against spell-chucking wizards and hordes of goblins, mighty dragons and mythical creations, otherworldly beasts, and unimaginable foes.

And guess what? You can make it even stranger if you like, and one of those ways is by introducing Aberrations into your campaign.

What Are Aberrations 5e?

Aberrations are a creature type found in the Monster Manual and are described as…

“Aberrations are utterly alien beings. Many themes have innate magical abilities drawn from the creature’s alien mind rather than the mystical forces of the world. The quintessential aberrations are aboleths, beholders, mind flayers, and slaadi.”

… which is a description that gives us a little bit to work with but which is also vague enough to allow the Dungeon Master to use this merely as a platform to build on and add their own unique ideas and flavors.

For the most part, when you think of Aberrations, you need to think of the weirdest creature already found in the rules and then take those ideas into even more extreme territory. Aberrations are alien, grotesque, unimaginable, and mind-blowing.

Inspiration can be found in the pages of books where fantasy tips over into horror. The Old Ones with the unpronounceable names that Lovecraft wrote about, the creatures lurking in the stories of Arthur Machen, and perhaps some of the stranger creatures that Michael Moorcock’s various heroes found themselves pitted against. Horror films, dark fantasy, even science fiction… Ripley’s titular Alien antagonist is indeed an Aberration.

Aberrations are going to look different from what you have seen before. They might be giant, squid-like things or sluggish behemoths.

They might resemble a creature you have seen before but will also have unnatural additions, horns, tentacles, extra eyes, too many mouths, and a disproportionate number of heads. They might be millipedal or bat-like or just a strange mix of beasts.

Whatever you decide they look like, they will be vast, unnatural, and awe-inspiring.

Where Do Aberrations Come From?

The D&D world might be strange, but its residents are, by and large, well-understood by those around them. Orcish warlords, Gnoll bandits, and Kobold raiding parties, their motivations and methods are well-understood by those they prey on and the adventurers who come up against them. Their mindset is going to be similar to everyone else.

Even ancient dragons have intelligence and worldview not a million miles away from the average human. Indeed in the most up-to-date rules of D&D 5e, most of what used to be the antagonistic races, the foes and fiends encountered whilst adventuring, have found their way into the rules as playable races.

So, we can assume that, by and large, such races are motivated by the same things and are all looking for similar things out of life — food, shelter, a stack of shiny things, and the odd bit of random violence. 

Aberrations are not like that. They are… well, who knows? They are not of this world and so not subject to the, mainly, logical motivations and standard thought patterns that most mortal creatures act on.

They don’t originate on the Material Plane; their presence in the mortal planes of existence means they have traveled from some far-flung outer plane, the astral realm, or the ethereal plane. You may want to introduce the idea of alien planets into your universe, and Aberrations are creatures more often found in science fiction.

Wherever you decide their homeland is, they are far from home, and their reasons for being here are bounded only by the DM’s imagination.

You may want to make things even more abstract. There may be a whole additional realm of Far Outer planes that these Aberrations call home, somewhere beyond even the home of the gods.

Or, as in Lovecraft’s creation, they have been here all along, lying dormant, “not dead but sleeping” in the deepest oceans, their perception of time such that the thousands of years that they have lain slumbering is just a blink of the eye to them.

How Do Aberrations Behave in the Mortal World?

Now, there’s a question. If you think that Fey creatures or even Devils and Demons are odd and unpredictable, at least it is fair to assume that they are driven by fun, trickery, greed, and malice.

They are just out to mess with you or get something from you. Aberrations could be here for any number of reasons. But they are not just out for fun; you probably only have a little they need. 

In the books of Lovecraft and Machen, such beasts generally want to be worshipped as gods; there is always an ego at work, even with such alien beasts. Perhaps they are all but forgotten gods from a time before and are trying to reestablish themselves and need followers to do their bidding and help them increase their powers.

They may be alien beings from far-off planets and are just here to check this world out. Maybe they got stuck here, or the flow of time works differently for them, and their millennia hidden out on the floor of the Sunless Sea is just their way of preparing for their mission.

However they operate in your world, it is traits such as paranoia, ego malice, and selfishness that should be at the fore of their personality. Still, for all their seeming madness, they will also be practical creatures.

After all, they have traveled millions of miles or crossed vast otherworlds taking millennia to get here; this isn’t just a random act taken on a whim. This is part of a purposeful plan that only they know of.

The Personality of Aberrations 5e

Again, this is an open area. The overall personality, if they can be said to have one, is really up to the DM creating them. But for a few guidelines, we can look at the more common Aberrations, that is, those already found in the rules.

Firstly, there are Mind Flayers. They are efficient and logical in their goals and how to achieve them. They are cunning, cautious, and focused.

On the other hand, Beholders are grumpy and paranoid, which can cause them to behave bizarrely. They are prone to lash out at real or perceived threats; in their world, almost everything can be seen as a threat.

Aboleths are just one big bundle of hatred, but they like to be worshipped and will collect followers and encourage them to form cults so that they can be worshipped and have their bidding done.

Overall, an Aberration’s goals are easy to understand when taken on an individual basis but when creating these more fantastic versions of the creature, bear in mind that they are individuals, million years old (probably), and not of this world/plane, so it is hard to draw any collective conclusions as to common traits or expected motivations. But here are a few ideas keeping with such a creature.

They hate mortals — they might have found their way to the mortal world, but that doesn’t mean that they like you, far from it. You are, at best, pawns in their game. You are pieces to be played to further their own ends.

You are creatures that should honor them, worship them, and further their own ambitions. Any deviation from such a path, any act of disobedience, or anything that displeases them will result in retribution, the like you have never even dreamed of. 

They hate the gods — they may be god-like, and you may even want to treat them as gods in their own right within the game, but they hate all others. They may be looking to overthrow the younger deities, which usurped them from their positions of power. Perhaps they are at war with their own kind, and this world is just one more battleground, its inhabitants, its military playthings sent to fight on their behalf.

They use psychic powers/mental manipulation to create thralls and cults — if Aberrations are physically big, that is not where their main strengths lay. Any creature millions of years old, which hails from a high-tech alien world or has gone beyond time and mortality, will have worked out long ago that physical confrontation is a very inefficient way to get things done. (Though they won’t have a problem with them dying on their behalf.)

Instead, they will have developed psychic abilities and mental prowess. This they will use to draw others to its cause. It will find champions and establish cult followings, either by offering rewards or by sending its followers slightly mad so that they can only see the world from the Aberration’s perspective.

Their goals typically revolve around conquering/destroying the world/cosmos — it is fair to say that you don’t matter to them. Neither does your world. And your whole plane of existence is a bit of an irrelevancy.

The Aberration’s plans often include the complete destruction of worlds, maybe even the entire universe. Perhaps it is only through the removal of this cosmos that they can return to theirs. Possibly existence — new gods, worlds, planes of existence, everything you can perceive in the world must be removed so that they can go back to sleep in the perpetual nothingness of the time before. Now that is a big ambition.

There are usually tentacles involved — Aberrations need to look impressive, otherworldly, and awe-inspiring. Think snakes, spiders, squid, or anything not humanoid in shape is an excellent place to start. Read the books of Lovecraft and check out the strange mythos he created. The creatures found there is a reasonable basis for these greater Aberrations. And, as is the law laid down in his books…There are usually tentacles involved…and lots of them.

When designing your own Aberrations, remember that there are no hard and fast rules. Just as their form can be as different and unexpected as you like, so can their motivations and methods, something that makes it extremely difficult to second guess when you encounter them.

Mind Flayers can rely on a collective hivemind to help navigate encounters. Beholders are powerful and physically aggressive, and Aboleths rely on a host of cultish followers to protect and fight for them. Each type of Aberration has its own set of solutions, so if you decide to build your own, make sure they come with their own set of surprising solutions.

The only common factor is that they will have no empathy to the point that they actively hate anything that crosses their path and are self-absorbed.

Making the Aberration unique to your world

Whereas most of the monsters that the players encounter will be those found in the rule books, Aberrations are your opportunity to throw them a curve ball. As players become more experienced, read more of the rules, and retain the knowledge of how everything works, some mystery can be lost.

When the party encounters the same creatures repeatedly, they will know just how to defend against them, learn how they are likely to attack, and understand their weak points. Aberrations don’t think like other creatures, and if you are building your own to add to the creature canon, then the players really are going to be in the dark regarding how best to defeat them.

Aberrations and their followers

One of the great things about Aberrations is their reliance on followers, especially as Aberrations are able to grant additional powers to them. Weaponize them, if you like, and use them as their military chess pieces motivating them, playing them, sacrificing them to keep themself safe.


One of the common themes in the literature and films that you find such Aberrations in is their effect on the sanity of those who encounter them. This is also especially true of those who serve them. When the characters encounter an Aberration, it is fair to ask them to make a saving throw against their sanity. (The rules for this are found on page 265 of the Dungeon Master’s Guide.)

After all, we are talking about a creature so horrific and otherworldly, so grotesque and unimaginable that it is likely to fry the character’s brain or at least drive them away screaming in horror. There are some things that even the most steely adventurer will not be able to handle.

Not only does the Aberration look… well, abhorrent… hence the name, the madness and magic, psychic power, and sense of horror that they exude is enough to drive anyone’s mental state over the edge.

Using a sanity check rather than the more normal Wisdom check seems more in keeping with the nature of the beast. This is not just some gnarly troll or even devilish denizen of the underworld.

This is the stuff from beyond nightmares. Having characters lose the plot in the face of an Aberration seems fair and perhaps even introduces rules for such bouts of insanity to be contagious.

 Big Aberrations and how to summon them

Okay, first, let’s define “Big Aberrations.” Well, at least a Beholder or Aboleth, certainly an Elder Brain. And, of course, anything that you create in the image of these Great Old Ones that we keep using as a reference point is definitely in the big category.

Aberrations love a good ritual. They can’t get enough mortal sacrifices; they adore blood rites and endless chants in long-forgotten languages — the more eldritch, the better. So when you want to bring your newly created, big bad Aberration into the game, then some wild ceremony or weird ritual is the way to do it.

Not only do you have a perfect answer to why the world is only just hearing about this strange creature from beyond time and reality, but you also have a great hook onto which you can hang a whole adventure. Maybe even use it as the backdrop to your entire campaign world.

The ritual can be as odd and arbitrary as you like. The followers may all wear the same color. Perhaps they need to collect particular ritual objects (again, a good adventure hook when ancient artifacts are being stolen all over the city).

A specific individual must be ritually sacrificed (one of the character’s brother-in-law). Remember that the Aberration doesn’t care whatever you opt for. It is just the key that opens the door to this realm, and nothing should get in the way of his arrival.


You could argue that followers of an Aberration will only stick around if there is something in it for them. That being in a cult needs to be a two-way street. If so, give your Aberration the ability to bestow additional powers on its followers.

Not everyone but indeed the high priests. Give them lower-level spells, inherent skills, powers, and insights. (Isn’t this where Warlocks come from anyway, don’t their powers and spells come from communing with such eldritch powers?)

But such power comes with a price. These greater Aberrations have tremendous power. More than most mortals could handle, so even a tiny taste of it will begin to warp the body and the mind. As the followers gain powers bestowed by their beast (who, to them, is a deity), they are subject to mutilation and madness. These effects are the benefit itself… the growing of claws and horns that can be used in combat and the development of psychic powers at the cost of their sanity.

Now the Aberration has the followers where they want them. Disobey, and you lose these additional skills and powers (but probably retain the madness and mental torture that goes with them. Death might also be the price for betrayal, but perhaps a lingering death that takes thousands of years.

Aberration Cults

We have established that Aberrations like to be adored and often collect mortals about them to do their bidding. These followers quickly turn into organized (or not so organized) cults. Such cults mean that you may never encounter the Aberration that they worship.

Instead, the players constantly come up against its minions. Why risk getting into combat with adventuring heroes when you have an army of followers willing to lay down their life for you?

Perhaps such cults are preparing the way for the Great One’s arrival, and the party is tasked with thwarting their efforts before they can raise it into this world. This will give you plenty of adventure ideas and possibly even the backbone of your whole campaign.

And what happens should they succeed? A war between them and the gods, a religious crusade amongst the mortal races…the world is your oyster. (Especially if it is a millennia-old, dimension-traveling oyster with special powers and a hatred for all life.)

Final Thoughts on Aberrations

So, there you have it. Aberrations can be more than just another creature to battle; they can be whole plot lines. Bumping into a Mind Flayer in a castle keep might be an exciting encounter, but why not think a bit more outside the box?

What if you encounter a few cultists robbing a church for an ancient artifact? Which leads the players to their main temple deep in the forest. Which reveals that they are going to raise an ancient god-like Aberration.

And what if they succeed? What if that leads to a holy war between the established church and the ever-growing cultist following? And which side are the players on? Do they play both sides against the other, or do they champion a cause? 

Aberrations. Your campaign is a better place for having them. (Well, not better, but you know what I mean.)

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09/23/2023 09:00 am GMT
Aberrations 5e DnD