Heirloom of Darkness - A Horror D&D 5e Module

Heirloom of Darkness - A Horror D&D 5e Module

Since it is near the end of the month known as Halloween I decided to write a module in the spirit of all things spooky. This module in particular has some inspiration from the more Lovecraftian side of horror. I will note that I ran this module through two different groups and tried some variations on what they went through. I had feelings varying from dislike to “it was extremely engaging” so this module is not for everyone.

Note that I use the Dungeons and Dragons 5th Edition (D&D 5e) system with the optional rules for Sanity highlighted in the Dungeon Master’s Guide (DMG). I also did my play testing over voice chat and roll20, so I could not achieve the full creep factor of this mansion. Also, due to the lack of preparation, I did not use music or prerecorded sounds. During the explanation of this module I will also talk about some of my thought processes when creating some of these rooms.

This module – while designed for my personal homebrew world – is capable of being planted in your own world. I will note details that you will need to fill in to fit your personal world – or any other world that you use – in brackets.

Running the Module

First things first: have all of your players write up their characters. I permitted just about anything but the one thing I told them was that they were adventurers answering to a wanted poster they had found during their travels. This may limit some characters that can’t read or do not care about the affairs of others. It is up to you to determine what you will allow. Grant magic items according to your personal choice or according to your own world.

This module was designed for three 10th-level characters, but I also ran it with a group of four 8th-level characters – the math just worked out for the encounters I had created. Have each person roll a 7th ability score – Sanity. This score can be increased like any other score for their Ability Score Improvement feature.

I have started using Sanity in my normal campaigns for this effect. This is important because having a player roll a Sanity save creates a different level of fear than just having them roll a Wisdom save. Then, when failing a Sanity saving throw, if they fail by more than 5 I have them roll on the long-term madness table. Rolling a natural 1 on a Sanity saving throw will result in a roll on the indefinite madness table. All other failures will result in a roll on the short-term madness table. The madness tables can be found on page 259-260 of the DMG or you can use your own rules for madness.

During the game I highly recommend the use of ambience music, sound effects, and voices – either generated by yourself or prerecorded – as this will add to the feeling of dread. I will be making note of times in which I used various sound effects or voices.

Descriptions in this module are key because they either give the right details to be scary or not enough to leave the characters guessing. When asking for specific details – I personally – would grant them whether or not the detail exists.

The Difficulty Challenges (DCs) that I use for this module are flexible. Since this module can be really rough on players it is up to you as the DM to make executive decision on if a player passes. This allows you to adjust the challenge as you go to either make it more difficult or easier on your players.


Your heroes, along their own personal journeys or in groups, if their characters know each other, come across the following wanted poster:

“Adventurers Wanted! Mr. Delron Vespir would like to hire a group of adventurers in reclaiming a lost artifact. Inquire in [Rivertan].”

Each group has made their way to [Rivertan] and in their own ways have discovered the location of Mr. Delron Vespir’s home. They each come to find that his home is one of the smaller mansions that rests in the town. It is not nearly as ornate or gaudy as the other mansions.

It is at this point that you determine who arrives at what times – preferably in a closely timed manner. When they knock on the door – or make their way inside by some other means – they will be greeted by an elderly male human with gaunt features and white hair. He asks them their business – or tries to kick them out. If they mention the job posting he will escort them to the dining room to wait until Mr. Vespir is available. Play this out until each player has made their way to the dining room.

Once all the players have arrived, a maid will bring drinks – wine – out for them to enjoy. Give the players a chance to mingle and get to know each other before Mr. Vespir arrives.

Once you have felt that the conversation has gone on for long enough – or the players simple do not spend long mingling – have Mr. Vespir show up to the dining room. Mr. Vespir is a 6-foot tall half-elf with sharp features and blond hair. He wears robes of deep blue and walks with a sense of superiority – very upright with chin held higher than normal. Allow him to introduce himself, if possible give him a very serious voice.

Once introductions have been concluded it is time for Mr. Vespir to explain the job. He states that his uncle passed about about three weeks ago in the mansion roughly two miles north of town due to “mysterious circumstances”. With him died the location of a family heirloom. Members of Mr. Vespir’s own staff that he sent to go retrieve it have not returned, hence the wanted poster. He says that the heirloom is a very ornate jewelry box – or so his mother tells him.

If a player passes on a Wisdom (Insight) check of DC 18, they will gather that he is telling the truth but that he is not telling the full story. When asked further about it he claims ignorance.

He will offer the players a reward of 5,000 gold pieces (gp) a piece should they retrieve the heirloom. Should this not be enough – either by player complaint or of your own – feel free to raise the reward. This is the incentive for the players to go to the mansion. If possible try to keep the price reasonable as later on they will understand that they are not being paid enough for this. On their way out he will quickly mention in a more serious tone: “Do NOT open the box, whatever you do.”

This prologue was designed to accomplish three things:

  1. Set a goal with a reward.

  2. Set the seeds to an overall story.

  3. Give a sense of mystery surrounding this heirloom and the uncle’s mysterious death.

With all of the story set the players are ready to take on the mansion, or so they think.

The Mansion of Blega Tarloog

Approaching the Mansion

As your players head towards the mansion make sure to tell them that it is approaching nightfall. Should they stop to camp for the night, have a storm roll in or an eclipse to occur. Whatever happens they should be approaching the mansion as it gets darker.

When describing the mansion to them fit the architecture with the surrounding area. In my world the town of Rivertan is just outside of the Halfling territory so I have it a combination of Halfing, Human, and Elven. This includes leaves, gold trimming, marble, and wood.

However the architecture looks make sure to give the house a sense of life. Describe the mansion as almost breathing and that it is looking at you. The inside of the mansion has no lights on but looks like there ispossibly movement, though it may just be shadows. Plants in the front of the house seem to almost move, but then you quickly notice that it is just a breeze that is moving them.

The front door is not locked.

I would recommend not letting players go through the windows, as this allowed them to avoid certain content that would have been important to know. If they try to go through the windows make it seem like no matter how high they get, it’s just not quite enough to get up. If they throw a grappling hook, make it slip off of the ledge. This is one of the important parts to railroad the players, but after this allow them to go in any direction they want.

First Floor



The first area the players walk into will become the central hub in which they explore the remainder of the mansion and where several events take place. This helps give a sense of security as you begin to mess with them from here on out. This room will also give them a clue as to what they are attempting to find.

From the last light that they receive from the outside they are able to get a good look at a majority of the room. Two staircases lead up to a second floor balcony that lead to the remainder of the second floor. They are able to see five sets of doors, one of which is chained shut – the bottom left door on the map. Hanging from the ceiling is a brilliant chandelier and below that sits the focus of the room.

On the floor is a large circle that is etched into the floor with several strange symbols. These are not in any language that the party can understand and using comprehend languages will result in the caster taking a DC 15 Sanity saving throw; either way they will not understand what they read. On closer inspection players will notice that three of the symbols are etched deeper than the others.

On the rightmost staircase the party can notice a portion of the railing to the balcony above broken and on the staircase. After the party returns to the entryway from one of the rooms an event is triggered where the ghostly figure of a woman begins to back away from something coming down that hallway. She falls over the balcony – the party hearing an audible cracking noise – as she begins to weep and drag herself to the study. Should the party attempt to attack her, they will notice that she does not respond.

Once all players have entered the mansion the front door slams shut and the mansion descends into complete darkness. If looking up at the windows the players will notice a leathery surface just outside the windows. On closer inspection eyes open up on the leathery surface. The viewer must make a DC 13 Sanity saving throw. Once the save has been made they will not have to make it again for seeing the surface. This surface will be found outside of every window in the house so if they miss it here, they will certainly encounter it later.

Navigating the Mansion

There are a few things to note before your players begin to navigate the mansion. First is that they will not be able to escape until the final sequence in the entryway – or they all die here. Even by magical means they will be blocked.

While this may be seen as cruel, it is to give a sense of no control over their current position. You want your players to feel out of their element and unable to escape it. Lack of absolute control is a great way to put fear into your players. Ultimately where they go determines the horrors they will face.

For story purposes this mansion was consumed by an Old God. The Old God you choose can be based on your world, or if you have a warlock of the Great Old One it can be their patron. Because Old Gods are mysterious it is difficult to say why magically getting out would be so challenging.

Bath House

The door to the lower right of the entryway leads to the the bath house. In this room is a large volume of water with a fountain in the center. When players look at the water for the first time have them make a DC 18 Wisdom (Perception) check. On a failure the water appears as normal. On a success the character is able to see through the illusion and notice that the water is actually blood. Upon seeing the blood, the character must make a DC 13 Sanity saving throw.

At the bottom of the bath is a shining gold amulet in the shape of a strange symbol. This is one of the three keys that the players must find for the entryway. Characters that see the blood cannot see the amulet.

The bath however is not just blood, it is alive. As a player gets close to the bath – or go in the bath – the blood will attack them. The bath is statted a slightly more powerful water elemental with some creative liberties on its attacks. The bath is focused on trying to drown whomever it can grapple.

During the fight characters that can see the blood will notice a humanoid form begin to form out of the bath. Other characters will not be able to see this and see all attacks coming from the bath as moving water. This is largely for flavor and a bit of a distraction from the rest of the bath.

Feel free to come up with interesting attacks for this creature, like a wave that attempts to drag everyone within 5 feet of the bath into it or a portion of it pulling itself out of the bath in order to attack characters further away.

When designing this room I wanted to create a challenge that both portions of the party would face. Seeing the blood allowed them to properly prepare for the battle while not being able to see the objective, while the others could see the objective but not properly prepare for the the fight.

Non-perceptive Parties

It is perfectly okay that parties do not notice the keys in the rooms. Since they do not know where the keys are, they will be forced to return to rooms they previously visited in order to find them. In a way this can cause more tension for the party as they know some of the strange things they have to face.


This room is lined with shelves of books of various topics. On the opposite wall they will also see a door that has been boarded shut. On the far side of the room that the players enter they will notice a desk with shelves surrounding it filled with various body parts of various races. One of these jars is the creature that will cause the party the most headache in this room, a Brain in a Jar.

The description of the desk with jars is one of the most important details that you need to describe carefully. Getting into too much detail gives away a large challenge with this encounter while giving little to no detail makes this challenge near impossible. If the party begins to investigate the jars make note that out of everything in the jars the brain is the most strange thing here – as most characters may have never seen a brain.

When investigating the door make loud pounding noises as a female voice yells, “GET ME OUT OF HERE! HELP!” Those perceptive enough can determine this was the voice of the woman from the entryway – given that the particular event has occurred.

Opening the door – either by breaking it down or pulling off all of the boards – will reveal a small shrine room dedicated to [Temp, the God of Life] that has been desecrated. Inside the players will find a corpse of a woman and a ghost staring at them. The ghost will begin shouting, “Why did you kill our son!” as she begins to attack the party.

The fight with the brain in the jar creates a combat encounter that the party cannot initially find and forces them to come up with a solution. The ghost is merely a distraction that reveals an interesting story element.


Beyond the double doors across from the mansion’s entrance lies the greenhouse. Outside of the window is the leathery surface with eyes (Sanity checks for those who haven’t seen it yet). The greenhouse is filled with lush green plants and vines that occupy much of the room. Dangling on the far side of the room by vines is one of the amulets for the entryway circle.

As some of you have probably guessed, and your players have as well, the vines will attempt to attack the players grappling them. The vines are easy to kill and are vulnerable to fire. However many that are killed they keep growing back.

Allow your players to be creative with this encounter and have the plants fight back in anyway you think is interesting. This includes them using dropped weapons or throwing broken down doors.


The remaining room that isn’t chained up is this dreadful kitchen. Once opening the door a horrible smell quaffs out. How you handle characters smelling terrible things is up to you. I personally enforce Constitution saving throws to avoid vomiting.

What they see inside appears to be prepared food, however on closer inspection is humanoid flesh. This will require a DC 13 Sanity saving throw.

One of the doors leads to the outside, which the players are unable to open due to the mass of flesh that blocks it. The other two doors are unlocked. One leads to a pantry where the corpse of an adventurer lies. On his person he has a mundane longsword and shield along with an explorer’s pack.

The last door leads to the dining room.

Dining Room

The door to this room leading to the entryway is chained from the entryway, requiring a DC 13 Thieve’s Tools check or a DC 15 Strength check. Inside there are two long sets of tables and one table sitting perpendicular to them at the far end of the room. A less powerful smell that came from the kitchen resides in this room.

In the darkness the players encounter about five eyeless creatures with razor sharp teeth and light skin with no hair. They are consuming various flesh that seems to have been left in this room. On their person are weapons and gear that a normal adventurer would wear. These are statted as thugs but without a crossbow and replacing their mace attack with a bite and a claw attack (each doing the same amount of damage but as slashing and piercing).

They are not the real threat, just the distraction. On the ceiling is an eldritch horror that clings there, taking up about a 20-foot radius in the center of the room. This creature has the following stats:


Clinging Horror

AC 18

HP 93

Speed: 10 ft., Climb 10 ft.

Str 18, Dex 8, Con 17, Int 19, Wis 16, Cha 6

Senses Darkvision 120 ft., Passive perception 16

Languages Deep Speech, Undercommon, telepathy 120 ft.

Magic Resistance. The Horror has advantage on saving throws against spells and other magical effects.

Innate Spellcasting (Psionics). The Horror’s innate spellcasting ability is Intelligence (spell save DC 15). It can innately cast the following spells, requiring no components.

At will: Detect thoughts, levitate

1/day each: dominate monster

Spider climb. The horror can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.


Multiattack. The horror makes four attacks with its tentacles, uses Reel, and makes one bite attack.

Tentacles. Melee Weapon Attack: +7 to hit, reach 50 ft., one creature. Hit: the target is grappled (escape DC 15). Until the grapple ends, the target must succeed on a DC 15 Intelligence saving throw or be stunned until the grapple ends. They can attempt the save at the end of each of their turns.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 4d8 +4 piercing damage

Reel. The horror pulls each creature grapple this way by it up to 25 feet straight towards it.


Those of you who read the Monster manual will notice this is a combination between a mindflayer and a roper. I found the mind-blast of a mindflayer to be way too strong, however this creature still runs the risk of wiping the party if they all fail their saving throws. When/if eldritch horror telepathically communicates to any of the players, have them roll a DC 15 Sanity saving throw.

Both the dining room and the kitchen are hints to the dark deeds being performed in this house. The gear being worn by the eye-less horrors is to imply that these were once adventurers that were sent to this very house and turned by the dark magics.

Long Rests

The party may be tempted to take a long rest during this module. Since this is a horror themed module and only designed to be one or two sessions long make this a challenge for them. For each hour they sleep require them to make Wisdom saving throws of increased difficulty as whispers haunt their minds.

To add to the lore of the house, have one of the players have to save against the possession by the ghostly woman. While possessed have them stab another player in their sleep while screaming, “Why did you kill our son?” This is assuming that the players did not already kill the ghost in the shrine room.

Second Floor


Master Bedroom

The room immediately at the top of the stairs is the master bedroom. In this room is a larger bed with curtains covering the inside of the bed area. Perceptive players will notice something hanging from the top of the bed frame. There are also several bookshelves, a desk, and some dressers.

Hanging from the bed is the dead body of Blega Tarloog, he has a stab wound in his chest and several long iron nails sticking out of his body. Next to the bed is a hammer and in one of the night stands next to the bed is the knife. The sheets are covered in dry blood and look as if someone had been sleeping in it.

If the players do enough damage to the body from a distance have the body break out of the ropes and roll across the floor towards them.

On the desk players will notice a leather bound journal. Inside it has the name Blega Tarloog. Scanning the journal will reveal that after a certain point the handwriting becomes sloppier to the point of being illegible. If they inquire about the journal here are some key points to make depending on where they look:

  1. Various entries on business trips and eventually an expedition into the [Sundering Mountains].

  2. The entry before the handwriting changes describes an expedition into the [Sundering Mountains]. They found a cave that had been previously undiscovered and they were going to explore it the next day.

  3. The entry that the handwriting changes describes his entire team going crazy and killing themselves after they found massive, sleeping creature. He awake later with the creature missing.

  4. The entry after talks of his discovery of a jewelry box among his possessions. He does not know its origin, only that it seems to be talking to him.

  5. He opens the box only to feel a great sense of power rush over him.

  6. Entries of great magical power, but also of extreme paranoia. There is mention of the construction of a hiding place where the jewelry box will be kept.

  7. His paranoia begins to be among his family he plots to kill his wife and son before they can acquire the box. All entries are illegible after this one.

The books on the shelves on cosmology and magic theory. Among his other things is a coin purse with about 50 gp within.

While there is no combat encounter in this room, both of my groups without fail attacked the corpse. This room provides context and clues to what has been going on in this house between its residents.

Wife’s Room

On the easternmost side of the second floor lies the room of the late wife. This room is different depending on if this room or the child’s room is visited first. If the players visit this room before the child’s room then they will hear shuffling if they listen through the door.

On the inside they will find a small doll that is rummaging through the vanity found in this room. Around it’s neck is one of the amulets for the central room. The doll will attempt to escape through a hole in the ceiling to climb back to the child’s room. The doll is incredibly easy to beat and was stat as a homonculus.

Within this room can be found some very expensive jewelry and perfumes. On top of that is a diary. If read the player’s can gather the following information:

  1. Life seemed normal but she was concerned for her husband’s safety on his trip.

  2. Once her husband returned home, he seemed changed.

  3. She believes that he is becoming too paranoid.

  4. After one evening of her being out of the home, she comes back to find their son dead. In response she sneaks into her husband’s room and stabs him in the chest. Something strange comes over her and she begins putting nails into his body and hangs him from the bed to bleed to death. She wants to leave. The journal entry seems incomplete.

Child’s Room

In my personal opinion this is one of the scarier rooms in the mansion. When listening through the door the players will hear a quiet “Help me.” While not a jump scare it really sends chills up your spine. Should the player crack the door to look through have it so they see another face looking at them through the crack.

Depending on if the players killed the doll in the wife’s room will determine the face. If the doll is still intact then have the face of the doll looking through, otherwise have the face be of a ghost looking through. This is because the doll is being possessed by the ghost of the uncle’s son.

If they burst through the door have nothing be behind the door. Instead they see the room of a small child, probably around the age of 7. Should they investigate under the bed they will find the doll looking back at them, or the ghost depending on if the doll survived.

Guest Room

This final room is less deadly to the players than most of the other rooms but is filled with an element that makes the players think. In this guest bedroom is a moaning corpse lying on the bed. At the foot of the bed can be found an explorer’s pack and a shortsword. Nothing else of interest can be found in the room but is an interesting point to the fact that they are not the first adventurers and that sleeping here could end up lethal.

Putting the Pieces Together

Once the players return to the entryway and place all of the amulets in the slots associated with them a few things start to happen. First, the floor begins to open up revealing a rising pedestal with a small ornate jewelry box. The intricate designs on the box are that of several greenish tentacles. Second, the front door flies open and a familiar humanoid figure begins to emerge from the leathery surface. They come face to face with a man who looks like the corpse from the master bedroom.

This man will shout “No one takes my box! None shall have its power!” This occurs while he is pulling himself out of the wall with tentacles coming out of his back. They begin to creep into his back and seal shut, giving a sign of warning about a feature of the upcoming fight. This is when you begin initiative.

This fight can result in one of three ways: the whole party dies, the party kills Blega, or one of the party members opens the box. When a party member grabs the box Blega targets them until they are dead or drop the box. Once Blega is dead the leathery surface surrounding the house begins to recede and is once again open to the outside once more.

Blega Tarloog

AC 14

HP 120

Speed 30 ft.

Str 11, Dex 13, Con 18, Int 12, Wis 6, Cha 20

Languages Common, Elven, Telepathy 30 ft.

Entropic Ward.  When a creature makes an attack roll against Blega he can use his reaction to impose disadvantage on that roll. If the attack misses he gains advantage on the next attack roll against that creature.

Thought Shield. Blega's thoughts can't be read by telepathy or other means. He has resistance to psychic damage and when he takes psychic damage he deals psychic damage to the one inflicting it.

Spellcasting. Blega's spellcasting ability is Charisma (spell save DC 18). He can cast the following spells:

At will: eldritch blast, chill touch, poison spray, blad ward

3/day : dominate person, dispel magic, counterspell, blight, shatter, hunger of hadar, invisibility, hold monster, Evard's black

1/day each: finger of death, eyebite

Tentacle Grasp. Whenever a creature deals damage to Blega while flanking have them roll a DC 15 Dexterity saving throw or be grappled. Only one creature can be grappled this way.


Multiattack Blega makes two rapier attacks

Rapier Melee Weapon Attack: +6 to hit, 5 ft., one creature, 1d8 + 1 piercing damage and 5 necrotic damage. Creature must succeed on an Intelligence saving throw of DC 18 or take an additional 1d8 psychic damage.

Escaping the Mansion

The only escape from the mansion is to defeat Blega. From here the party is welcome to go wherever they choose. This however is not the ending to their story. If the party sets up camp ask them the order that they keep watch. The final encounter will occur in the first watch.

Being granted the location of the unopened box by his patron, Mr. Delron Vespir makes an appearance after using a wand to cast silence on the camp. From here he uses whatever means he needs to reach the box such as using misty step to get to the location of the box. Because the Great Old One imparted knowledge on him to its location he does not need to search for it.

Mr. Delron Vespir does not attack the party and will not target them with a spell unless it is to acquire the box. Once he gets the box he uses a key to open the box. The only way for the party to survive this module is to kill Mr. Vespir, destroy the box, or for one of the players to open the box (saving only themselves).

Should the players take the box directly to Mr. Vespir after escaping the mansion, he opens the box while they are there.

Opening the Box

When a player grabs the jewelry box they are greeted with a deep voice that tells them to open the box. When/if they refuse the voice will try to give them a compelling reason to, be it wealth beyond their wildest dreams or the power to save their friends.

The box however is locked. Opening it requires a DC 10 Thieves’ Tools check or a DC 12 Strength check. This is to keep players from opening the box immediately. Opening the box ends the module.

When the box is opened a dark figure shrouded in shadow rises out of the box. Tendrils leap from the figures form and wrap themselves around all characters that did not open the box. When the tendrils begin to pull each character they find that it is not pulling their bodies but their souls. Their souls are then absorbed into the shadowy figure and those characters are dead, their bodies now lifeless husks.

The one who opened the box may be no better off. Now that character is a Warlock and will only take levels of warlock from here on out. They have become a pawn of the Great Old One and will then take over the mansion.

The box can be destroyed only by divine intervention or a wish spell. Even then the box will rematerialize somewhere in the next 100 years.

To Be Continued?

I hope you enjoyed this module as I put lots of thought and play testing into it. This module may be considered cruel due to the low chance of success, but this was designed as a horror module. Taking away a player’s agency is one element of storytelling. For a long campaign I would not recommend this tactic often.

It is entirely possible for you to run this campaign with a different group and have the last person to open the box be the new “final” boss. Should the party survive this could be the hook to a long-term campaign however I would not count on it.

You probably noticed that I do not have a lot of loot nor do I dish out experience. The lack of loot is to make the players feel like their characters are not getting paid enough for this. Experience has always been something that I felt has gotten in the way of immersion and since this module relies so heavily on immersion and player buy-in, I took it out entirely.