Prepare for the release of Explorer’s Guide to Wildemount by playing your own encounters in the world of Critical Role! This encounter is based off of “Mimics in the Mine,” a low-level adventure hook presented in Explorer’s Guide to Wildemount, which you can preorder now on the D&D Beyond Marketplace!

The latest D&D campaign setting explores the world of Critical Role in Explorer's Guide to Wildemount, now available for preorder on the D&D Beyond Marketplace. Wildemount is a land of dark and epic fantasy, with low-level characters fighting to survive in a world full of common folk who are just as mud-splattered and hungry as they are—and high-level characters contending with the fate of nations and magic that has the power to bring about the end of the world, or the creation of a new one. This series of Encounters of the Week are one-shot adventures for low-level characters set in the four major regions of Wildemount: the grim, authoritarian Dwendalian Empire; Xhorhas, home of their mortal rival the Kryn Dynasty; the tropical and politically neutral Menagerie Coast; and the frozen and forbidden Greying Wildlands, home to strange mystics and every sort of criminal scum.

Still from the Critical Role animated intro, by Kami Areopagita (@karekareo)

The Dwarven Stronghold of Grimgolir

Nestled in the southern Dunrock Mountains that separate the Dwendalian Empire from the wastes of Xhorhas lies the great stronghold-city of Grimgolir. Once a separate entity from both sides with a history of clashes with the Empire, King Bertrand Dwendal now counts the Grimgol dwarves as one of the most important allies in the war against the Kryn Dynasty, perfectly situated as they are to watch over the eastern border.

Primarily dwarven, Grimgolir is a society that, like many dwarves, prizes exceptional craftsmanship and even more exceptional skill on the battlefield. Every man, woman, and child of Grimgolir is trained in basic combat from a very young age. Native-born Grimgolirans are expected to carve out their futures in the Monoliths, the military force of the city-state, or as warriors or craftspeople. However, even those unskilled in these areas may find purpose as miners or smiths in service to the Bleeding Stone Syndicate, Grimgolir’s primary mining enterprise.

Encounter Summary

Workers are being killed in a series of mysterious attacks in the Grimgoliran mines. The well-trained dwarves can find neither hide nor hair of their assailants, and operations have stalled as their miners fear their mysterious new enemy. The characters are hired to investigate and discover at their foe isn’t a Kryn scouting force, as the warriors of Grimgolir suspect, but an infestation of mimics that have been ambushing the miners and using their equipment to blend in with their surroundings. When faced with an enemy that can disguise itself perfectly, will the characters be able to find the source of the creatures before it’s too late?

Encounter Start

This encounter is designed for 4th level characters and assumes that the characters have been in Grimgolir long enough to have heard of the problem or have been hired based on reputation to deal with the situation.

Over the last week, the Bleeding Stone Syndicate’s mining operations have ground to a screeching halt. Unseen assailants have been attacking miners and no one has been able to find the culprits. The most recent attack in the newest tunnels left three workers dead and no clues to the causes of death.

The characters are led by a squad of Monoliths (the elite force of dwarven soldiers in Grimgolir) through the city to the Heart Ward where Brock Dummaroff, the Underbaron and ruler of the city is having a meeting with a group of Bleeding Stone representatives outside the barracks. Dummaroff notices the characters as they approach and beckons them to him. After introducing himself, he launches into explanations. Read or paraphrase the following:

“Someone—or something—has to be attacking our people,” Underbaron Dummaroff says. “Our mining operations cannot continue if the situation is not resolved, and the Empire is relying on our ore to support the war effort.” There are murmurs from the surrounding dwarves that are quickly drowned out by Dummaroff’s protestations. “I don’t care what we have to do to root the creatures out! I will not see another dwarf die needlessly.”

Dummaroff knows the following information:

• The attacks began in earnest a few weeks ago. A group of workers was excavating a new tunnel, but were found dead when the time to change shifts came. Their bodies were found cleanly stripped of flesh and tissue; naught but snapped and gnawed bones remained. A thorough search of the tunnel by Monoliths turned up nothing.
• The attacks increased violently upon completion and ignition of a new furnace at the furthest end of the tunnel. They did manage to label the tunnel before they abandoned the mine completely.
• The people of Grimgolir fear that the Kryn have somehow burrowed into their mining tunnels and are trying to disrupt their industry. The Dummaroff is skeptical, since the miners were killed in such a bestial way. He suspects that Kryn invaders brought war-beasts into the tunnels with them.

Dummaroff is willing to pay a handsome sum to the characters if they can find and root out the cause of the attacks. If they agree, he leads them to a sealed off and guarded tunnel entrance. He wishes them the blessings of Moradin the All-Hammer and leaves them to enter the mine alone.

Entering the Mine

The tunnels and caverns of the mine have been hewn from the rock of the mountains. These features are common throughout:

Ceilings. The ceilings throughout are seven to eight feet high and braced at regular intervals by wooden beams. Carved chambers can have ceilings as high as 10 feet. Cavern ceilings are natural and can be 50 feet at their highest.

Light. Lanterns hang from every support beam and from hooks in every area, but the miners’ haste to leave the area has left the lanterns low on oil. All areas are dimly lit.

Doors. Doors are made of wood with iron hinges. They are unlocked, as the miners fled in haste.

Mimic-Tools. This mine is filled with young mimics using their Shapechanger and False Apperance traits to appear to be discarded mining tools. These mimic-tools use mimic statistics with the following changes, which reduce their challenge rating to 1/2 (100 XP):

• Their size is Small and they have an AC of 10.
• They have 16 (3d6 + 6) hit points.
• Their Pseudopod attack deals 5 (1d6 + 1) bludgeoning damage and their Bite attack deals 5 (1d6 + 1) piercing damage plus 2 (1d4) acid damage.

These young mimics take the shape of pickaxes, hooded lanterns, chisels, hammers, shovels, and so forth. If one of the mimics is touched, the entire pile attacks that character, and any other mimics within 20 feet of the pile attack their allies. Each pile of mimic-tools acts on the same initiative.

To drive the miners out in such a hurry there must be dozens, if not hundreds of them pretending to be who knows what in these tunnels. The characters can make any manner of creative checks from the players to help determine what may be a mimic and what may not, but keep in mind that a mimic’s False Appearance is impossible to see through—the best indication is that mimic-tools are free of dust and grime.

1. Tunnel Entrance

The mine is eerily quiet without the clamor of dwarves working the tunnels. The 5-foot wide tunnel entrance the adventurers enter through is the one most recently dug, with support beams supporting the walls and ceiling every 10 feet. Lanterns hung on the beams cast dim light in a 20-foot radius; just barely enough light for a creature without darkvision to see.

As the characters travel down the 100 foot long tunnel, the evidence of the miners’ leaving in haste becomes visible. Pickaxes and shovels lay strewn about the ground, lanterns have been knocked off of their hooks, their oil spilled and soaked into the ground. At the end of the tunnel, a door leading to the miners’ common area is open.

This chamber is free of danger; the mimics are too cautious to advance this close to the heart of Grimgolir. Characters may make Wisdom (Survival) or Intelligence (Investigation) checks as they progress. On a result of 10 or higher, they notice that all of the tools here are covered in stone dust and grime, as if they were left in a great hurry.

2. Common Area

You emerge from the tunnel into a long hall that looks as if it was once a common area for miners. A pair of double doors are slightly ajar at the end of the hall, and piles of mining tools have been left in front of the double doors.  

This hall is 10 feet wide and 50 feet long, then terminates a set of open double doors, beyond which is the main mining cavern (area 6). In the middle of the hall, on the left and right walls, are three wooden doors. One on the left leads to a supply room (area 3), one on the right leads to living quarters (area 4), and another on the left leads to a kitchen and mess hall (area 5).

Mimic Ambush! The double doors in this room are mimics (they use typical mimic statistics rather than the modified mimic-tool statistics above). There are three piles of 1d6 mimic-tools: one in front of the doors, and another to the left and right. If any of the mimics are disturbed, they all spring to life and attack.

3. Supply Rooms

Mining equipment the dwarves were not using has been stored in three 10-by-10 foot rooms separated by open archways and arranged in a straight line. Shovels and picks have been thrown haphazardly into barrels and crates or tossed against walls, and lanterns hang from pegs with leftover flasks of oil sitting on a shelf beneath them.

A group of 12 mimic-tools have cleverly arranged themselves as saws, hammers, and other hand-tools hanging from a wooden tool-rack on the far end the central supply room. Beneath this tool-rack is a locked chest; the mimics only attack once someone is distracted by unlocking or opening the chest.

Suspicious Chest. This wooden chest is reinforced with steel bands and has a large and obvious lock. It’s not a mimic, as much as it may seem so. A character can smash it open by making a successful DC 13 Strength check, or pick its lock with a successful DC 15 Dexterity check with thieves’ tools. Inside is a set of three +1 light hammers used for particularly tough rocks.

4. Living Quarters

This 20-by-40 foot room contains 8 bunk beds in various states of disarray. A DC 13 Intelligence (Investigation) check shows that the room has been this way for a while. All of the beds have chests at the foot of them, but several are overturned. Spare tunics and personal items have been tossed out of them.

Searching the remaining chests reveals three potions of healing, as well as several ruby shards worth 100 gp. While the characters are busy searching, one of the bunk beds reveals itself to be a mimic and tries to sneak up and bludgeon them to death.

5. Kitchen and Mess Hall

The dining area in the mess hall is one large 40-foot long slab of stone that appears to have been carved out of the floor itself. Wooden plates, bowls, and eating utensils are scattered all about the room. The kitchen area is set into one of the walls and contains pantry shelves, a sink with a few inches of stagnant water at the bottom, and an unlit fireplace.

6. Open Cavern

Beyond the double doors, the main tunnel continues for about fifty feet before opening up into a wide cavern with rough, stone walls. A few low-burning oil lamps flicker dully in the darkness. At the far end of the room are a trio of mine carts.

This wide cavern is roughly 60 feet in diameter. This cavern was to be the primary hub of this mining tunnel. The lanterns hanging from the walls are low on oil; each sheds dim light in a 10-foot radius, leaving the middle of the cavern and ceiling in near darkness. At the far end of the room, the tunnel dips down into total darkness.

Even in the dim light, it’s possible to see the evidence of the miners’ misfortune. Dark stains a few feet in diameter dot the stone floor. A character that makes a successful DC 12 Wisdom (Medicine) check determines that the stains are blood. They appear to be several days old, and the shape of the splatter indicates that they were made by something falling onto someone from above.

Six piercers lurk on the ceiling of this cavern, waiting for the best moment to strike. Any character that stops to investigate blood splatter is a prime target for the slow-moving creatures, who are spread all across the 40-foot high ceiling. If the characters choose to investigate the ceiling, roll a Dexterity (Stealth) check for the piercers against the characters’ passive Wisdom (Perception) scores.

Mine carts Going Down

Three 10-foot wide gently sloping tunnels lead out of this open cavern, though two have been closed off. At the mouth of each tunnel, three mine carts on iron rails are secured with wooden chocks. Each mine cart has a handbrake and a hook for a lantern.

A wooden sign over the tunnel reads “To Furnace: 500 feet”. Characters may opt to use the carts for faster travel. Each cart can hold two Medium-sized humanoids.

Operating the Minecarts. If the chocks securing the cart are removed, the cart will begin to roll. Its initial speed of 10 feet increases by 10 feet every round until it comes to the end of the track or reaches its maximum speed of 50 feet. The cart will stop if it reaches the guard barrier at either end of the track or if it hits another cart.

A creature inside the cart or next to it can use its action to pull the handbrake to reduce the cart’s speed up to 25 feet, bringing it to a stop if its speed reaches zero.

The middle mine cart is a giant mimic to that reveals itself once the carts reach top speed. It will use its Adhesive ability to keep characters inside itself while it Bites them and attacks characters in the adjacent carts with its Pseudopod.

(If you don’t own Waterdeep: Dragon Heist, you can represent the giant mimic by using mimic statistics and increasing its size to Large and its hit points to 75, and changing its Multiattack to grant it three attacks: two with its pseudopods and one with its bite.)

The characters may be more interested in attempting escape rather than fighting. Adhered characters can attempt to make a DC 13 Strength (Athletics) or Dexterity (Acrobatics) check to free themselves from the mimic and jump from the mine cart. Characters must make a DC 10 Dexterity saving throw or take 10 (3d6) bludgeoning damage unless they manage to slow the carts down. They must also make this check if they don’t manage to slow the carts down before they reach the guard barrier at the end of the tunnel.

If the characters escape the carts without defeating the mimic, the carts will travel at speed to the end of the tunnel. Beyond is the final area of the dungeon: the furnace.

Fuel for the Furnace

As they approach the end of the tunnel, the temperature begins to rise. The furnace room is just beyond the tunnel; a circular room 40 feet in diameter. Its only contents are the furnace, a feeder at the top of the furnace for coal, and a shovel. Beyond that, they see that the fire in the furnace is at full blast and the room is littered with amorphous blobs: mimics in their true forms that have been using the room’s burning conditions as a breeding ground.

The furnace needs to be extinguished to stop the mimics from reproducing. The following conditions must be met:

• The burning coals must be removed from the furnace. A character holding a shovel can remove a lump of coals from the furnace. Doing this three times is enough to empty the furnace of coals. A character that gets close enough to the furnace to remove the coals must succeed on a DC 10 Constitution saving throw or gain a level of exhaustion. Creatures with resistance to fire damage have advantage on this save.
• The feeder must be turned away from the top of the furnace. A character can use their action to make a DC 13 Strength check, turning the feeder away on a success.
• The fire must be extinguished. Once the burning coals are removed, the flames die down in 1 minute. Alternatively, dumping 10 gallons of water into the furnace at once (with create or destroy water), blowing strong wind into the furnace (with gust of wind), smothering the flame with dirt (using erupting earth), or using another creative solution extinguishes the flames immediately.

There are six young mimics (using the mimic-tool stats from earlier) in the furnace room as well. At the start of each round, another mimic-tool appears from a crack in the floor. It is not necessary to defeat them all if the furnace can be stopped beforehand.

When the Flames Die Down

With the furnace extinguished, the breeding conditions of the mimics can no longer be satisfied. The characters make their way back to the Heart Ward of Grimgolir and, should they inform Underbaron Dummaroff of the situation, he immediately begins plans to send Monoliths into the mines to find and exterminate the remaining mimics.

The Underbaron thanks the characters profusely for taking care of their problem; he invites them to his estate in the Cage Ward to stay and recover from their ordeal. Dummaroff sees to the characters’ every comfort for as long as they stay in Grimgolir, and when they are ready to depart, he awards them with 500 gp, a cloak of protection and a belt of dwarvenkind as thanks.

You can continue your daring adventures through the land with Explorer’s Guide to Wildemount, coming to D&D Beyond on March 17th, 2020, with preorders available now. You can also keep up with the adventures across Wildemount in Critical Role, every Thursday at 7:00 pm PST on www.twitch.tv/CriticalRole.

Did you like this encounter? Check out the other encounters in the Encounter of the Week series, and preorder Explorer's Guide to Wildemount on D&D Beyond to get four starter adventures set in Wildemount—in the Menagerie Coast, Dwendalian Empire, Xhorhas, and the Greying Wildlands—including an adventure written by Matthew Mercer himself!

LaTia Jacquise is a contributing writer for D&D Beyond, Wizards of the Coast, and Adventurers League, as well as one of the Community Managers for the D&D Adventurers League Organized Play program. Based in Chicago and a self-proclaimed “Forever DM”, she frequently travels to conventions across the Midwest to bring her love of D&D to as many people as she can. You can find her spending entirely too much time on Twitter at @theladytiefling.