Last Updated on January 22, 2023
Aboleths are ancient and enormous (well, technically large) aberrations from the dawn of time. They are intelligent, powerful, and worst of all, careful. These tentacled creatures are not the most personally powerful creatures a party can face, but they have a habit of using clever tactics and numerous allies to make themselves extremely hard to destroy.
Let’s take a look.
So, what exactly can an aboleth do?
- STR 21 (+5), DEX 9 (-1), CON 15 (+2), INT 18 (+4), WIS 15 (+2), CHA 18 (+4)
- AC: 17 (natural armor)
- Hitpoints: 18d10+36 (135 avg)
- Saving Throws: CON +6, INT +8, WIS +6
- Speed: 10 ft., swim 40 ft.
- Skills: History (+12), Perception (+10)
- Proficiency Bonus: +4
- Senses: 120 ft. of Darkvision and 20 Passive Perception
- Languages: Deep Speech, telepathy (120 ft.)
- Challenge Rating: 10
Aboleths are tough creatures with senses suited for their deep-water living. Notably, they also have surprisingly good mental stats, so don’t count on Wisdom saves to take out these behemoths.
Aboleth abilities are primarily oriented around water. They are Amphibious, able to breathe air and water. Moving on to the alarming abilities, they have Probing Telepathy, enabling them to learn a creature’s greatest desires on telepathic and visual contact. Finally, they emit a Mucous Cloud while underwater. Creatures that touch this cloud (by hitting it with a melee attack or just touching the aboleth) have to make a DC 14 Constitution saving throw.
On failure, this disease lasts for 1d4 hours. It has no effect for the first minute and can be cured by any magic that removes disease. After that, though, the creature’s skin becomes slimy, and they can’t regain hitpoints or breathe unless underwater. The Heal spell or something similar of at least 6th level that can cure diseases is the only way to get rid of the effect.
To make matters worse, when the creature is outside of a body of water, it takes 1d12 (6 avg) acid damage every 10 minutes unless it can keep itself moist.
Aboleths have several actions available to them in combat. With Multiattack, the aboleth makes three melee tentacle attacks with a reach of 10 feet and a +9 to hit. These tentacles do 2d5+5 (12 avg.) bludgeoning damage, and if the target is a creature, it must make a Constitution save against being diseased on hit as per the Mucous Cloud ability.
Aboleths can also attack with their tails (+9 to hit, 10-foot melee range) for 3d6+5 (15 avg.) bludgeoning damage, though this takes their whole action.
Alarmingly, aboleths can attempt to Enslave a creature three times a day. Any creature within the aboleth’s visual field targeted by this ability must make a DC 14 Wisdom saving throw or be magically charmed by the aboleth until either it dies or the two are no longer on the same plane of existence. A telepathic bond is also formed that works over any distance so the aboleth can maintain control.
Enslaved creatures can’t take reactions but can repeat the saving throw if they take damage or if they’re more than a mile away from the aboleth for the first time in a given 24-hour period.
Yes, it’s true. In addition to being mind-controlling body-transforming tentacled monsters of the water, aboleths also get legendary actions. Three times per round after another creature’s turn the aboleth can take a legendary action.
This action can either be Detect (allowing the aboleth to make a Wisdom (Perception) check), Tail Swipe (granting an extra tail attack), or Psychic Drain, which at the cost of two actions deals 3d6 (10 avg) psychic damage to a creature the aboleth has charmed and heals the aboleth for the amount of damage the creature takes.
Finally, aboleths have lair actions they can take on initiative count 20 when they are in their lair. These actions can take one of three forms.
The aboleth can cast Phantasmal Force without components on any number of creatures it can see within 60 feet. This is a powerful ability but one that requires concentration; the aboleth can’t use other lair actions while concentrating on it. Also, targets that make their save against the aboleth’s spell are immune to it for the next 24 hours.
The aboleth can also make pools of water within 90 feet flood outwards, forcing a DC 14 Strength save on any creature within 20 feet of such pool. Failing the save means being pulled 20 feet into the water and knocked prone.
Lastly, the aboleth can make water in its lair become a conduit for 2d6 (7 avg) psychic damage. Creatures take this damage if the aboleth can see them and if they fail a DC 14 Wisdom saving throw.
These are pretty rough, but at least the aboleth needs to mix it up; it can’t use either of the last two lair actions twice in a row.
Memories of the Deep
Aboleths are ancient creatures. Existing since before the gods, they ruled the pre-divine universe until they were cast down… and they haven’t forgotten.
Aboleths have perfect memories and can pass memories down through the generations. That means every aboleth has the combined perfect knowledge of every aboleth that came before it. Moreover, aboleths can’t actually die. Killing one only destroys its physical form. Its spirit returns to the Elemental Plane of Water where it can create a new body for itself.
These creatures are essentially immortal geniuses with access to a vast amount of knowledge, a grudge against the divine, and an intense desire to be worshiped. The campaign practically writes itself!
Aboleth tactics can be complex and fighting back even more so. The range of abilities and lore behind an aboleth means that countering them requires understanding exactly what they can do and how they do it effectively.
However, it’s very easy to run an aboleth poorly. If you don’t take advantage of tactics and simply try to face it off against a prepared party, all the aboleth’s fancy abilities will be meaningless, and it’ll get shredded.
Follow the lore and the tactics below, however, and you can give even veteran parties a real run for their money.
Aboleths are deeply intelligent creatures with millennia of knowledge and experience at their command. They know how to tell a Hexblade warlock from an Eldritch Knight fighter and the most efficient way of destroying either. All their actions will be extremely tactical, and if they can gather any intel on the party before the fight, they can tweak their strategies to the players’ weaknesses.
Thus, aboleths will often try to maneuver a situation such that they can win before combat even starts by manipulating a situation or tricking the party into acting on bad intelligence.
Aboleths can’t be killed, but death is still an inconvenience. Being banished back to the Elemental Plane of Water means that they lose control over anyone they’ve enslaved. That could be several hundred followers, and an aboleth will hate to lose such an investment.
They enjoy being worshiped but don’t care about any particular follower as long as they still have a following. They are less interested in killing nosy adventurers as they are making those adventurers serve them.
An aboleth will play it a lot more cautiously than your average tentacled sea monster. They’ll watch the party and gather intel as much as possible, and when the party invades their lair, they might not attack right away, if ever.
Moreover, a party is very unlikely to ever face an aboleth without followers. They may be able to engineer the situation to face the aboleth 1-on-1 as it were, but if the aboleth has any say in the matter, it’ll have minions. How many minions and how strong they are will significantly swing the difficulty of the fight.
Remember that an aboleth by itself is CR 10. That estimation always goes up with friends.
When gathering intel on an adventuring party, the aboleth will make use of its Detect legendary action to assess the party and try to guess who has the worst Wisdom save. It might even try to Enslave a party member or two before the fight, making them into sleeper cells for the aboleth.
This doesn’t sound scary at first. A target gets a new saving throw every time it takes damage, so it’s not as if the aboleth can hold on to a party member for too long in combat.
But imagine what would happen if your party was all underwater and in combat when your sorcerer suddenly casts Dispel Magic on the Water Breathing spell keeping everyone alive. Even a single round of a surprise betrayal can result in a party wipe.
When combat actually occurs, an aboleth will primarily lean on its tentacle multiattack for damage as well as minions. Once it has landed a few blows on various enemies, it’ll retreat into the water for at least a minute. That doesn’t mean the fight is over though.
The aboleth’s disease will sound weak for combat to many players; it takes a full minute to take effect, and most combat encounters only last a few rounds. However, the aboleth is under no obligation to stay and fight for that entire minute while it waits for the disease to take effect.
Once a party member has died from suffocation or entered the water to be able to breathe, the aboleth will strike. In the latter case, it can easily grapple an underwater party member and swim away with them entirely, capturing them in order to eventually convert them into a follower with its Enslave ability and an unlucky save.
D&D 5e parties excel at straightforward combat encounters that end with the party dead or victorious. The aboleth will deny your players that luxury, and an encounter with one of these creatures will take several minutes as the aboleth repeatedly throws attacks at the players and retreats to await its disease and use its Psychic Drain ability to heal itself.
If the players find they have to rescue one of their own, the encounter could take days.
The aboleth’s Psychic Drain ability has no range, and so long as all the creatures it has enslaved remain within 1 mile of it, the aboleth could have thousands of creatures under its command (beyond 1 mile, many of the creatures will eventually make their saves).
That means that, given about a minute and a half, an aboleth can heal itself to full as long as it has enough followers with enough hitpoints to burn through.
Finally, during the entirety of combat, the aboleth will be sending telepathic messages of temptation to the players. If any player responds in their head and the aboleth can see them, the aboleth will be able to tempt the player with their greatest desire, potentially bypassing the need for magical control.
Can you truly trust all your party members, even that Chaotic Neutral rogue?
A Note on Lair Actions
Aboleths are careful, and the 1-mile limit on controlling their followers means that they usually stay in their lairs. That means that most of the time an aboleth encounter will take place on the aboleth’s home turf where lair actions add another layer of complexity to the fight.
While making use of lair actions is a no-brainer, you should actually be pretty particular about what order you use them. If you’re unfamiliar with lair actions, I strongly recommend checking out this article that goes more in depth.
Assuming you know how they work, let’s look at how your aboleth should use them.
In combat, an aboleth will usually rotate between grabbing players with water and using its ability to channel psychic damage to anyone in the water close enough to it. The former control ability is particularly useful for dragging adventurers into traps if not into the water with the aboleth itself. Remember that, once in the water, an adventurer is vulnerable to being grappled and stolen away.
However, prior to combat and occasionally in combat, the aboleth’s ability to cast Phantasmal Force will come into play.
This spell forces an illusion on a target that makes the target believe some phantasm is real to the point of being able to take 1d6 psychic damage from the phantasm whenever such damage would be appropriate.
This has a myriad number of uses in traps, tricks, and temptations — far too many to go into here. Bear in mind that aboleths have excellent darkvision and might be able to see the adventurers before they know it is there. As long as it can see them and they haven’t successfully made a save in the last 24 hours against the spell, the aboleth can target players with repeated phantasmal forces for uses limited only by your imagination.
Power Beyond Stats: A Crystal Cave
The aboleth’s tactics are shaped by its abilities and the kind of creature it is, but making the aboleth effective requires appropriate setup. That means not only a lair that maximizes the aboleth’s advantages while minimizing its weaknesses but also treating the aboleth like an ancient creature obsessed with power over mortals that’s had an unknown amount of time to establish its power base.
There are numerous ways to stack the deck in the aboleth’s favor. A powerful cult, traps, or even a small town or city of enslaved people the aboleth can use as a pool of hitpoints for healing are all ways an aboleth might strengthen itself over time.
However, my favorite way to make an aboleth powerful beyond its abilities is by carefully structuring its lair.
As an example, the aboleth’s lair might be a crystalline cave underwater. Several of the passages have only a little water in them, and these would be open to adventurers. However, large pools scattered through the cave system would lead to other tunnels that have fully flooded, and the aboleth navigates these perfectly.
The crystalline walls of the tunnel would allow the aboleth to see, albeit in a distorted way, any adventurers that enter its domain. It could navigate tunnels parallel to the adventurers, keeping an eye on them while using abilities like Enslave and Phantasmal Force.
By attacking briefly from the scattered pools of water before returning to the depths, the aboleth would be able to attack the party while being extremely difficult to target; the cave walls would be see-through but still make it difficult for the players to effectively target the aboleth, forcing them to pursue an underwater battle where the creature has an advantage.
This setup alone, without allies, slaves, or traps, would make an encounter with an aboleth a serious challenge capable of wiping a party not prepared for it. So, make sure to pay attention to the lair design if you want to set up an aboleth encounter!
If you’re fighting an aboleth, don’t go in the water. However ready you think your party or your character is for underwater combat, you aren’t as ready as the aboleth is. If you don’t have a swim speed, you’ll have disadvantage on all weapon attacks underwater and move at half speed.
Even if you have a swim speed, only daggers, javelins, shortswords, spears, tridents, crossbows, nets, and ranged weapons thrown like a javelin won’t impose disadvantage. Plus, all ranged weapons automatically miss beyond their normal range, and everyone gets resistance to fire damage.
Fighting in water where an aboleth has the advantage in attacks, abilities, maneuverability, senses (it’s pretty dark at the bottom of the ocean), and knowledge of the terrain is a bad idea.
Beyond not going in the water, it’s important to be able to counter the aboleth’s abilities. Keep a Detect Disease up to make sure you can cure the disease within a minute with a quick spell. If you wait too long to cure it, you’ll have to use a 6th-level spell slot to save your friends.
Use Protection from Good and Evil to prevent the Aboleth from mind controlling your party members.
Make use of ability buffs to prevent yourself from being dragged underwater or grappled, and make sure everyone in the party has Water Breathing cast on them for worst-case scenarios. Teleportation abilities can also ensure a safe escape from the aboleth’s attempted kidnapping.
You’ll also want to do your research on whatever allies the aboleth has and try to ensure you don’t have to fight them and the aboleth at the same time.
Remember the aboleth can communicate with those it has enslaved. If you’re in a town an aboleth has control over, no one can be trusted, and you should assume that every interaction you have with anyone is being spied on by the aboleth itself.
Lastly, many of the aboleth’s abilities rely on sight to function. Deny it that with the spells Darkness, Fog Cloud, or Blindness/Deafness, and you’ll be able to protect yourself effectively. Even if this hampers your party, remember that as long as the aboleth is similarly hampered, you’ll still come out ahead and be able to survive longer.
Forcing the aboleth out of the water is the biggest advantage you can give yourselves. You might be able to do this by freezing enough of the water in the area so that the aboleth has to come onto land or is denied access back into the water.
However, control spells like Telekinesis might be more effective at dragging the aberration out of the ocean. Once exposed, it won’t be able to retreat to heal itself or attack you psychically, so your party will be able to simply out-damage it.
The spell Control Water might also help with exposing the aboleth. We have an article here that explains exactly how the spell works and what it can do, but essentially you can use it to pull the water away from the aboleth or try and trap it in a vortex so it can’t escape the damage from your party.
The 4th-level spell Banishment can also be extremely effective here; if the aboleth fails the save, you can force it permanently off the Material Plane until it can find its own route back. This will also free anyone enslaved by the aboleth, destroying its cult.
On the face of it, aboleths are tough CR10 monsters with an interesting suit of abilities that can provide a neat challenge to your party, perhaps as a dungeon boss.
However, when you consider the lore and the ways aboleths can use their abilities to expand their power, they can become quite scary. Imagine how many people can live in a two-mile radius. Imagine the political leadership of an empire entirely under the mental command of an aboleth. Imagine the armies and wizards an aboleth might command.
These immortal creatures, left alone to gather power and worshippers, can become powerful enough to drive campaigns and challenge parties of even level 15. True, they can’t become infinitely powerful, but they are extremely good at remaining subtle, and even deadly adventurers might have a hard time knowing exactly where to stick their swords before the aboleth’s minions catch up with them.
Of course, you can always run aboleths as simple monsters in a dungeon with a small cult and a few traps, but if you do include one of these creatures in your campaign or find you are facing an aboleth yourself as a player, remember their potential… and beware the water.
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Growing up I spent most of my time reading, so when I first started playing RPGs in middle school and got a copy of DnD 3.5’s rules I loved their collaborative take on storytelling. These days I like to use RPGs to develop my creative problem-solving skills as well.