The Lost Caverns of Tsojcanth is an expeditious, labyrinthian dungeon delve unearthed for Quests from the Infinite Staircase, a collection of beloved adventures. If you’re looking to send your table on a good old-fashioned, ill-advised treasure hunt through the former home of one of D&D’s most famous archmages, The Lost Caverns of Tsojcanth just might be calling your name.

Below we’ll explore the journey toward discovering the titular Lost Caverns, and what kinds of demons, dragons, and vampiric daughters they’ll find there.

Warning! This article contains minor spoilers for The Lost Caverns of Tsojcanth

• The Lost Caverns of Tsojcanth Adventure Overview
• Monster of the Week: Behir
• The Lost Caverns of Tsojcanth Adventure Hooks
• The Loot You’ll Find

The Lost Caverns of Tsojcanth Adventure Overview

Artist: MARK BEHM

Character level: 9 – If you use story-based level advancement, characters should reach level 11.

Location: A legendary, hidden series of caverns deep within a mountain range.

Themes: Pursuit of power, rivalries, underground horrors.

Adventure Premise

Tsojcanth may be the namesake of the mysterious lost caverns hidden away in the Yatil Mountains on the plane of Oerth, the world of Greyhawk, but the caves are more famous for their former resident, Iggwilv the Witch Queen. She made the lair her own and carved out a magical kingdom for herself by hoarding magical artifacts and binding demons to her will. When Iggwilv vanished after a battle with the demon lord Graz’zt, Iggwilv’s lair was lost, along with the treasures it contained.

A Beacon of Intrigue

In recent decades, surfacing clues have led to rumors and speculation about the lost lair. The stories of the riches and artifacts contained within have become a popular legend among the nations that border the Yatil Mountains. Each nation cares as much about preventing Iggwilv’s secrets from falling into the others’ hands as they do claiming it for themselves. Players can work for the margrave of one of these nations, or be in search of the treasure for another reason, or for themselves.

More Than a Dungeon Crawl

The "lost" part of The Lost Caverns of Tsojcanth really says it all. Before the players even get a chance to set foot in the cave, they’ll have to find it. The quest to do so serves as a first act to the adventure, with a few encounters littered throughout the Yatil Mountains to give the characters a chance to do some investigating to find their way in.

Danger Around Every Corner

Once inside the dungeon proper, the titular Tsojcanth tunnels are not for the faint of heart. Your players will find a sprawling, winding path of a dungeon. The foes they face will be a veritable rogues gallery of some of D&D’s most iconic monsters, such as trolls, basilisks, cloakers, stone giants, and even an adult black dragon, just to scratch the surface. And if those battles aren’t enough, traps and environmental dangers such as demonic pillars or interplanar travels into the Nine Hells await.

As the kind of dungeon that makes sure to include forageable mushrooms to consume on much needed Long Rests, The Lost Caverns of Tsojcanth has a little something for everyone.

The Witch Was There When It Was Written

While all the modules found in Quests from the Infinite Staircase hail from Dungeons & Dragons’ first edition, The Lost Caverns of Tsojcanth allows you to delve even deeper into the domain of D&D history. The first version of the adventure was created by Gary Gygax himself as a tournament adventure in 1976, six years before it would be expanded and revised in 1982. Newer players to the game might also recognize Iggwilv the Witch Queen by her more commonly used name: the Archmage Tasha, of Hideous Laughter or Cauldron of Everything fame.

Monster of the Week: Behir

The lightning breathing behir made its debut in the original version of The Lost Caverns of Tsojcanth. This CR 11 Monstrosity loves to make its home in hard to reach places, such as, say, a lost cavern full of monsters and threats, so that its prey comes to it, tired and weakened from their travels and easy to be swallowed whole.

Behir were originally created by storm giants to serve as a defense against dragons during long forgotten wars. As such, behirs still maintain a natural animosity toward dragons and will try to kill or drive off any that try to make their lair too close to the behir’s.

Behir Tactics

The behir has a Multiattack that includes both a Bite and Constrict attack. As previously mentioned, the behir also has a rechargeable Lightning Breath that does a whopping 12d10 in a 20 foot line on a failed Dexterity save, or half as much on a successful one. The behir can also use the Swallow action to make a grapple attack on a Medium creature, swallowing them whole on a success. While swallowed, a creature is Blinded and Restrained and takes Acid damage at the start of the behir’s turn.

The behir featured in The Lost Caverns of Tsojcanth has a name, Lludd, and is noted as being a clever creature who can speak Common and Giant in addition to the Draconic that most behir can speak. What makes Lludd such an interesting encounter is that there’s not one set way in which he’ll deal with the party. He can be convinced to let them go on in peace if he senses the adventurers would be a threat, but will be glad to fight them if they provoke him, or if he thinks they’re easy pickings. So Lludd is a great enemy for playing up the ways that player actions and choices can lead toward consequences or rewards.

The Lost Caverns of Tsojcanth Adventure Hooks

If your players aren’t already chomping at the bit to loot the horde of the Witch Queen, here are some more ways to entice them. Also while the original setting for the adventure is Oerth, there are suggestions in the module description for where to place the caverns on another of the D&D planes.

Nafas the Noble Genie

Quests from the Infinite Staircase has a built-in narrative structure for DMs who run the book’s adventures as a full campaign. This includes Nafas, an optional group patron who directs the party toward the various adventures in the book.

Nafas is a genie who hears wishes from across the multiverse and deploys the members of the party to help him grant them. For The Lost Caverns of Tsojcanth, he puts you in the path of an agent serving the ruler of a kingdom in search of the caverns’ fortune.

Lost Light

Quests from the Infinite Staircase also has a couple of options for groups that aren’t using Nafas.

A kingdom near the mountain range has fallen under a curse that they believe can only be lifted via an artifact, Daoud’s Wondrous Lanthorn. This magic item is believed to be hidden away in Iggwilv’s horde and the nation will beseech the adventurers to find it.

Racing Rivals

The margrave of a nation near the Yatil Mountains is fearful that his rival neighbors will find the treasure trove and be able to use it to bolster their power. He hires the characters to find it first and loot the coffers to weaken these neighbors without being seen as moving against them overtly.

While the description doesn’t explicitly suggest this, the idea of rivals heading toward the same treasure as the characters positively screams out for the inclusion of a group of adversarial adventurers to raise the stakes. A party of rivals like the ones highlighted in Critical Role: Call of the Netherdeep would be a fun addition to this adventure, especially if it’s being included as part of a longer campaign.

The Loot You’ll Find

As a legendary lair of loot, of course the things the players will find in The Lost Caverns of Tsojcanth are going to be pretty hefty. In riches alone, the adventurers can find a trove of items worth over 20,000 GP. Shelves of magical tomes give the Dungeon Master the discretion to reward players with any of the wondrous books, such as the Tome of Leadership and Influence, that over the course of six days allow for a permanent boost of an ability score by 2 points.

There are two unique magic items that can be found in the adventure:

• Heretic: This Legendary +3 Longsword is sentient and evil, and it definitely has it in for Celestials. Heretic has six charges that can be used to inflict the Paralyzed condition on a failed Constitution saving throw, or to cast the Detect Evil and Good, Fly, or True Seeing spells.
• Daoud’s Wondrous Lanthorn: As the name implies, this magical lantern sheds bright light that can reveal invisible objects or creatures within 60 feet. The lantern is an expensive item to use, however, fueled solely by crushed gemstones. Depending on which of the lantern’s focusing lenses is used, and the gemstones burned, you can use Daoud’s Wondrous Lanthorn to cast spells such as Prismatic Wall, Reverse Gravity, or Hold Monster. The lantern also has 2 minor beneficial properties, 1 major beneficial property, and 1 minor detrimental property from the Random Properties tables in the 2014 Dungeon Master’s Guide.

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Riley Silverman (@rileyjsilverman) is a contributing writer to D&D Beyond, Nerdist, and SYFY Wire. She DMs the Theros-set Dice Ex Machina for the Saving Throw Show, and has been a player on the Wizards of the Coast-sponsored The Broken Pact. Riley also played as Braga in the official tabletop adaptation of the Rat Queens comic for HyperRPG, and currently plays as The Doctor on the Doctor Who RPG podcast The Game of Rassilon. She currently lives in Los Angeles.