D&D Waterdeep Dragon Heist: Session 12

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Waterdeep: Dragon Heist

Dragon Heist Session Twelve: Intellect Devourer-ed

Not sure what to do next, and with no clear way to raise the funds needed, the four adventurers slumped into the debris of the tap room in Trollskull Manor. Lif could be heard upstairs smashing more furniture; Arvene was just about to go up and give him a piece of her mind when she heard a scratching below the floorboards. “If Lif’s up there,” she said, “Who’s down there?” Alan went down to the cellar to check. Moments later they heard him called up urgently, “Argh! It’s back! The brain monster with the handsy legs!”

Last night was the 12th session in our online Waterdeep Dragon Heist D&D campaign and it featured an encounter with an Intellect Devourer in the basement.

The set up

For our Dragon Heist campaign we are playing via Skype and using Trello and D&D Beyond to keep track of characters and share campaign information. I have also been using a second laptop with its own Skype account so that I can stream battle maps for encounters. This week, after some receiving some recommendations, we experimented with setting up a Discord server, and were going to play via that medium. However, I hadn’t factored in the need for a second laptop, so we postponed this trial to next week.

Dragon heist
The party battle an intellect devourer in the basement of Trollskull Alley

One set back last night was that our drow sorcerer was having wi-fi connection problems. This meant there were times when we had to guess what he was doing. Fortunately for us, he eventually came back online and we’d guessed about right.

Alongside the Dragon Heist campaign book I have been using additional resources from the DMs Guild to flesh our parts of the story, last night however it was just a case of throw a monster at them and see what happens…

The Party:

Alan Crabpopper, Human Ranger – a private investigator and low level thug.
Dugg, Earth Genasi Fighter – estranged son from a noble family.
Little Joe, Drow Sorcerer – channeling the spirit of John Wayne.
Arvene Galanodel, Half-Elf Cleric – priestess of Tymora, ex-city guard, ex-nun.

trollskull residents
The Party: Dugg, Alan, Arvene, Little Joe

Previously in Waterdeep: Dragon Heist

Alan, Dugg, Joe, and Arvene met in Waterdeep and formed a small independent investigations company called Dragonclaw Investigates. Their first mission was to save Floon Blagmaar who had fallen victim to the Xanathar/Zhentarim war that was raging on the streets. Whilst on that mission they encountered a Mindflayer and his pet, a human brain that scuttled around on six dexterous limbs and preyed upon ideas. This disgusting brain creature was called an Intellect Devourer and during the fracas it escaped into the sewers.

Days later, having eventually rescued Floon and receiving a crumbling mansion as payment, the heroes discovered exactly how much it was going to cost to renovate Trollskull Manor. Too much. Last session, as they sat contemplating their next move, presumably waiting for a dragon to heist, Alan heard a scratching sound coming from the cellar. He went to investigate and discovered the Intellect Devourer had returned.

Intellect Devourer

The cellar in Trollskull Manor was partially flooded and stank of stale water and refuse. Alan held his breath as he scanned the area for signs of movement. There was a chimney in the center of the basement that created a partition between the three main cellar areas, and something within the cast iron grill cover caught Alan’s eye. It moved. He was sure of it. It moved again, something small and shadowy in the pitch darkness. Then he heard splashing. And scuttling. Something leapt of out the darkness at him and he glimpsed the monstrous six-legged brain. “AAAAH!”


I like a session that begins with “Roll Initiative!” It’s a great way to get your players invested straight from the off. So that’s what I did. Normally we would have a recap or discuss what each of us could remember from last week, but not last night. We just went straight in with the gross-walking-brain-thing.

Dragon Heist
An Intellect Devourer, image by Mat Phillips

Joe was the first to act. He wasn’t really interested in wading down into the flooded cellar. There were at least six inches of murky liquid covering the ground and he had his best boots on. So he stayed on the stairs and cast Dancing Lights to give some illumination to the situation. His four glowing spheres joined together into one vaguely humanoid shape and he placed it centrally in the basement. This shed dim light in a 20-foot radius sphere allowing those without darkvision—Alan and Dugg—to see.

Dugg went next. He also started in the stairway and called to Alan, who was deep in the cellar, “What can you see?” “Another squishy leg-monster,” was the reply. Dugg shuddered. He was still traumatized from the first encounter with this thing. But he rushed in to save his friend regardless, ending up back-to-back with Alan. He held out his two shortswords, ready to fend off the beast.  

Arvene was next, but, before she moved, both Alan and Dugg heard splishing and scuttling from behind one of the many broken and moldy barrels. They yelled and pointed to where the sounds had come from. Arvene ran in, charging forward with her mace raised and caught a glimpse of the Intellect Devourer scurrying behind a wooden crate. She cast Sacred Flame towards where she thought it was and the crate instantly turned to ash and dust, leaving a quivering six-legged brain-monster behind it.

The brain rushed past her and across the cellar, providing Dugg with an opportunity to attack as it dashed past him. He caught the creature on one of its hind legs as it just passed his reach. It stumbled, but kept footing and hid in the shadows behind a wine rack.

Alan felt Dugg swing for the creature and spun around, just in time to see it scamper into the shadows. “There is it!” he called out and readied his own weapon should the beast come out.

I’ll just put the kettle on

Round two was much the same as round one. Little Joe—whose internet connection was very poor at this stage—decided to go upstairs and make sure the kettle was boiling ready for their post-encounter brew. Occasionally during the night I asked him to roll a concentration check, as his Dancing Lights were the only source of illumination in the basement. The first check he made successfully, and so for now the lights stayed on.

Even with Joe’s assistance, Dugg and Alan were both struggling with the limited visibility in the poorly lit basement. Each made attacks versus the Intellect Devourer, but did so with disadvantage. One of Dugg’s shortswords ended up stuck into an old wooden box, and he left it there because he was afraid the Intellect Devourer would get him as he tried to yank it free.

Meanwhile, Arvene, who could see—albeit only in monochrome—stood behind Alan and cast Guidance. This helpful buff gave him +d4 to his next roll. From her vantage point she didn’t see the Intellect Devourer sneak out from behind a barrel until it was too late. The six-legged brain leapt at her and slashed across her cheek with its horrible human-like hands. It dealt seven points of slashing damage from its claws and then tried to devour intellect.

Arvene felt the creature psychically pulling her thoughts from her mind. It was trying to consume her consciousness, but she fought back. She rolled well on her intelligence saving throw and was able to resist the effects.

Lif interference

Over the next couple of rounds, the three in the basement ran around in circles, trying to capture or kill the Intellect Devourer as Joe was upstairs making everyone tea. Dugg and Arvene both managed to hit the monster with attacks, but it had resistance to some non-magical damage so didn’t look too badly hurt.

Little Joe’s player was still having trouble with his internet connection, but whenever he reappeared I had him role a concentration check for Joe, who was being harried in his tea-making duties by Lif the not-so-friendly poltergeist. This gave the situation in the basement a sort of strobe lighting effect as his concentration dwindled then returned.

By the fifth round of combat Joe had lost concentration altogether on his Dancing Lights spell, leaving Alan and Dugg to stumble around blindly in the cellar. Eventually Alan tripped over and fell prone on the floor, hitting his head on the cast iron grill of the chimney stack. This played right into the Intellect Devourer’s six tiny human hands and it scuttled over and tried to devour Alan’s mind. Thanks to a Bless spell cast by Arvene, Alan was successful in his saving throw and his intellect was not devoured.

Intellect Devourer-ed

As written, the campaign book sees the party face this Intellect Devourer at the end of the Xanathar sewer crawl in chapter one. At that stage the PCs are only level one; they would stand no chance against it. Instead, at that time, I had the Intellect Devourer escape into the sewers. The heroes were so busy saving Floon that they were happy to let it go. However, I knew it would return.

Although it only has a low challenge rating, the Intellect Devourer is a very scary enemy. Especially in this scenario, in a dark, dank cellar, when you can’t see where it’s coming from.

The reason it is so scary is that, as well as having damage resistances from bludgeoning, piercing, and slashing attacks, it also has three main attacks it can use: Claws, Devour Intellect, and Body Thief. Claws aren’t an issue, but the other two can potentially change the course of a campaign. The Body Thief attack essentially magically replaces a player’s brain with the creature, leaving them a husk that can only be returned to normal with a Wish spell—not something that level one players have access to. This seemed a bit mean so I decided not to risk it.

But it was the other attack option, Devour Intellect, which I was most keen to explore. This seemed like it would be the most fun, as its effects—the character’s intelligence score is reduced to 0 and they are stunned until it is reversed—would provide a great chance for some interesting roleplay.

The Intellect Devourer tried to use this attack three times in this encounter and, if it wasn’t for Arvene’s Bless spell, which gave every a boost to their saving throws, one of them would have certainly had their intellect devoured.

But by the end of the fifth round each of the three basement battlers had resisted the Devour Intellect attack, and the monster was looking worse for wear. Not that they could all see it.

Devour this!

Realizing his spell had failed and his companions may need his help—also his player had fixed the internet issues—Little Joe ran down the stairs and re-cast Dancing Lights so the party could all see once more.

When the lights came back on Dugg realized he had the Intellect Devourer cornered. Arvene and Alan stood beside him as he slowly approach the beast, shortsword raised. Still glowing with Tymora’s blessing, Dugg raised his weapon and drove it home into the monster, splitting it in two. END

Dragon Heist
Intellect Devourer skewered


This was a fun session, almost entirely combat. After a couple of weeks of pure roleplay, this felt like a great way of keeping my players invested in the Dragon Heist story. It will also hopefully encourage them to think about their priorities, i.e., they really need to sort out the plumbing to stop more Intellect Devourers getting in the basement.

So what should they do now? Of course, it’s entirely up to them. There are a couple of Dragon Heist plot threads they could pull on: Alan has a date with wererats in a Watch House; Arevene could investigate the Sea Maiden’s Fair; Joe has been followed by Drow; and Dugg wants to report back to Mirt. There’s also the option of downtime activities, which I listed out for them on Trello.

Dragon Heist

What did we learn?

DM Tip: Sometimes, if your players aren’t taking the bait, you’ve got to beyond the source material. This session came about because I was finding it hard to motivate my players to renovate the mansion. It’ll cost a lot of gold that they don’t have, but Chapter 2 of Dragon Heist really wants the players to build up this base. I had to work out how I could incentivize them to do that. So I showed them that if they don’t do something about the plumbing and the renovations, who knows what other unwanted visitors may turn up in the basement?

Next week hopefully they’ll agree to have some work done; they may even find an investor who’s willing to help out. Either that, or they’ll spend the entire time visiting casinos, tailors, and restaurants, and I’ll have to set another Intellect Devourer on them…

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