In D&D, we treat the ‘Long Rest’ like a save point in a video game—a moment of absolute safety. The Incubus exists to prove that even your subconscious isn’t a safe harbor.

Incubi have traditionally been creatures of nightmare and desire, plaguing their victims with nighttime visions of fear, need, and violence until the poor, harried mortal passes from sheer exhaustion. And in D&D, they follow a very similar playbook.

An adventure that features an Incubus should be like a horror movie. Your Player should know that there’s something wrong, but not know what it is or who it’s coming from. These creatures can change their appearance, shift into the ethereal plane, and manipulate the dreams of their victims like skilled artists of terror.

Imagine this: your Party is walking through a night market, perhaps looking for food, a little entertainment, or that shifty contact who’s supposed to tell them where the key to the tomb of Fennix the Undying might be. The crowds are thick and dense, people moving without regards for who might be in their way.

Suddenly, your Warlock doubles over in pain, their head feeling like it’s going to split. Everyone looks around for an attacker, but it’s just… people. No one with a knife or a glowing crystal or a malicious look in their eyes. As far as they can tell, they have no one attacking them at all.

The beauty of the Incubus is that they aren’t looking for a fair fight. They are the ultimate gaslighters. After the Warlock’s nose bleeds, the Incubus, perhaps disguised as a concerned bystander, is the first one to offer a handkerchief. They’ve poisoned the well and then offered the antidote.

After the Warlock wipes the blood from their nose, assure the Party that they’re okay, they go about their business.

But… when the Party takes a moment to rest and recover, a time which your Warlock usually finds very refreshing, their mind is filled with roiling thoughts and terrible ideas, and the refreshment they get from the Short Rest just… doesn’t happen.

For the next day, your Warlock is wiped out and no one knows why. When they sleep, their dreams are nightmarish, full of visions of being hunted or plummeting towards the ground, or humiliated in front of those they love. and with every dream, they become weaker and more troubled.

And then it happens again.

The Incubus never looks the same twice – their skill with Disguise Self is such that they can look like anyone, and once per day they can shift into their Succubus form, which brings with it a whole host of new and terrible powers.

You can have the Incubus target a specific player (which doesn’t have to be the Warlock, but its Restless Touch is especially damaging to players who benefit the most from short rests), constantly coming to them for torment. They might look like a friendly shopkeeper or a helpful stable boy, perhaps even getting so far as to strike up a real relationship with them. All the while sipping from their vitality and filling their dreams with terror and dread.

And in the end, when they are finally unveiled and the Party finally asks Why?

Because it was fun. That’s why.

Of course, you can have your Incubus be a player in a much larger game. They are Fiends, after all, which means their seduction of your Player could be a smaller move in a much greater infernal plan. There’s nothing wrong with that, and it would actually be a great way to kick off a campaign that brings your Players to the Hells – maybe with each stolen dream, a piece of their soul goes with it, and the only way to retrieve it is to venture into the lands of the Devils.

Another option is that your Players have been sticking their noses in the wrong places, angering some powerful people who need them taken out of the picture. A human with ties to a Fiend may ask its patron to send some assistance to rid them of these troublesome adventurers, and the Incubus might be the one who shows up.

Actually finding the Incubus should play like a murder mystery. Try to find out who was where, and when. Look for inconsistencies in people’s stories or behavior. And for the DM, you can enjoy the Players’ rising paranoia as they see everyone as a suspect – every serving maid or street sweeper could be the Incubus in disguise.

And during this time, they’re wasting away. Little touches here and there start to make their rest less effective, their dreams more terrifying. It’s coming from everywhere and nowhere, and your Players should feel the ticking clock right behind them, counting down the moments until they waste away or are driven mad.

Of course, they may eventually pin down your Incubus. Having figured out who it is, they start a chase, but when they catch up, it looks like the Paladin’s sister or perhaps a fallen NPC – someone the Players told stories about to that nice guy in the tavern who bought them all drinks.

The further you push your Players with the Incubus, the more likely they’ll decide to fight it. But is that something the Incubus is even interested in? Probably not – it knows how to hurt people, and its way is never as direct or as crass as being in melee with them. For your more combat-oriented players, this will probably result in a frustratingly brief skirmish. The Incubus has no interest in a fair fight; it will simply slip into the Ethereal Plane, leaving the Party swinging at empty air. It’s not a defeat for the Incubus; it’s just a change of venue..

If no one has the right spells active, such as Truesight, that means the Incubus just… leaves and no one knows where it’s gone.

So how does your Party triumph over an Incubus and make it satisfying?

That’s up to you, really. They could find whoever summoned it and deal with them, for example. Imagine your exhausted, dream-maddened Warlock holding an Eldritch Blast to the head of some noble’s son, screaming at them to “CALL IT OFF!”

Or they seek out an expert in the Infernal, someone who has been to those hellish planes and back, who has a sure-fire way of getting the Incubus out of their lives. Of course, they won’t give that knowledge away for free, so there should be a whole new chain of quests that have to happen before the problem is well and truly solved.

There will be other ways as well – magical and mundane strategies that could be the means to getting rid of this threat to health and sanity. By the time they manage to get the Incubus problem solved, they’ll be different people, tested in ways that they never expected.

The danger of the Incubus isn’t that they take your life; it’s that they take your rest. In a world of monsters and gods, the most precious resource an adventurer has is their peace of mind. When that is gone, even the mightiest Paladin is just a tired person in a heavy suit of armor.

Don’t use an Incubus to kill your players. Use them to make your players afraid to close their eyes. Because once you’ve lost the ability to dream, the nightmare has already won.