D&D Heads Back to the Underdark In New Unearthed Arcana Playtest

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Dungeons & Dragons is heading back into the shadowy depths below in its latest Unearthed Arcana playtest. Entitled Underdark Options, much of this new UA is focused on the city of Deep Imaskar; an isolated subterranean enclave in the Forgotten Realms inhabited by the human descendants of an ancient, fallen empire.

The playtest introduces two new subclasses related to the mysterious metropolis: the Path of Unlight Barbarian and the Imaskarcanist Wizard, both of which are built around a volatile magical energy known as Unlight. The UA also includes a new dark elf-themed subclass known as the House Agent Rogue, which is steeped in the politics and infiltration techniques of the drow city of Menzoberranzan. The playtest also includes a new series of feats known as the Path of Ceremorphosis that allows you to slowly transition into becoming a Mind Flayer.

It’s not entirely clear what new sourcebook (if any) the materials will be appearing in given Wizards of the Coast’s current D&D release schedule for the remainder of 2026 and early 2027. It’s also not clear what plans they have for the enigmatic city of Deep Imaskar. Below, we dive deep into all the details.

What’s Included in the New Underdark Options Playtest?

The latest UA packet introduces three brand new subclasses, two of which are focused on a new magical power known as Unlight, which is used by the dwellers of Deep Imaskar to protect their city. In the wrong hands, however, this mysterious power can also corrupt and destroy, burning creatures from within until they die in a fiery explosion of brilliant light.

Barbarian: Path of Unlight

For barbarians who prefer to channel volatile, blazing arcane magic rather than simple brute rage, the Path of Unlight draws upon the lost secrets of Deep Imaskar. When you rage, Unlight infuses your body and you shed bright light in a 20-foot radius, granting you Blindsight within that area and inflicting radiant damage on anyone foolish enough to strike you in melee combat. At Level 10 you also unlock the Infectious Unlight ability, which allows you to transmit harmful Unlight effects onto a target, slowly destroying them from the inside.

Rogue: House Agent

Operating out of the intricate political webs and deadly shadows of drow houses from Menzoberranzan, the House Agent is a master of infiltration, espionage and social manipulation. Armed with a magical House Insignia that grants you thematic spellcasting (such as Charm Person, Suggestion and a spider-form Find Familiar), you can also leverage the Influence action as a Bonus Action. In addition, you can utilize cunning strike options like Stunning Betrayal to turn charmed or friendly targets against their allies.

Wizard: Imaskarcanist

Channeling the ancient, lost wizard-king arts of Deep Imaskar, the Imaskarcanist bends Unlight to both devastating and restorative ends. This subclass allows you to weave Unlight into your spellcasting, swapping traditional elemental damage types for pure radiant damage while manipulating light levels. Additional features like Unlight Restoration let you expend Hit Point Dice to heal allies or purge harmful conditions like paralysis and blindness. At Level 14 you also get access to Doom of Unlight, which infuses enemies with the volatile and corrosive radiant energy that literally tears them apart.

Path of Ceremorphosis (Feat)

Similar to the Path of the Lich and Path of the Death Knight materials that appeared in recent Unearthed Arcana Playtests, the Path of Ceremorphosis allows you to gradually become a Mind Flayer. The path and its features are in part influenced by Baldur’s Gate 3, which allows players to potentially become an Illithid.

Characters begin this process at level 4 or higher with the Tadpole Host feat, which grants an Intelligence increase, the Mind Sliver cantrip and a pool of Psionic Energy Dice that fuel abilities such as Psionic Overload. As you progress, you can select intermediate feats like Illithid Thrallmaker, Tadpole’s Safeguard or Ulitharid’s Might to upgrade your dice to d8s, gain telepathy and unlock thematic features like retaliatory psychic damage or extended physical tentacles.

Upon reaching level 12 or higher and selecting at least two prior feats, you can then take the Full Ceremorphosis feat to finalize your transformation into an Aberration. This capstone stage upgrades your Psionic Energy Dice to d10s or d12s and lets you choose from specialized illithid talents. These also grant access to powerful psiconic abilities, including enhanced tentacle attacks that can grapple foes, and innate spellcasting featuring spells like Mind Blast.

What is the city of Deep Imsaskar?

Deep Imaskar, also known as the City of the Great Seal, is a hidden and highly isolated city located in the lower Underdark of the Forgotten Realms. It was founded thousands of years ago by human refugees fleeing the destruction of the ancient Imaskar Empire.

The city is now inhabited by tall, thin pale-skinned humans who refer to themselves as Deep Imaskari and utilize extensive extradimensional spaces so that buildings are much larger on the inside than they appear on the outside.

Over the centuries, Deep Imaskar has been ruled by various councils and nobles known as “Planners” (including the Body of Planners and High Lord Planners). The settlement maintains its secrecy through a massive magical barrier called the Great Seal, which convinces outsiders that the Imaskari Empire has been completely destroyed, with no traces remaining.

In the real world, Deep Imaskar has appeared in several sourcebooks and novels over the years. For D&D third edition it appeared in the Underdark supplement in 2003 as well as in Lost Empires of Faerûn in 2005. It was also mentioned in the 4th edition Forgotten Realms Campaign Guide in 2008, which detailed its geography, society, and post-Spellplague state.

The city was also featured prominently in the 2006 D&D Forgotten Realms novel Darkvision by Bruce R. Cordell, which centered around a crisis involving the breach of the Great Seal.

Final Thoughts

It has been over a decade since D&D visited the Underdark, with the 2015 Out of the Abyss campaign book being the last time a 5E product really explored the subterranean realm. Wizards of the Coast has also had a somewhat complicated relationship with drow in the past few years, having moved away from treating them as a race of evil monsters and viewing them more as a playable species. That too, however, recently changed when the 2026 Adventures in Faerûn supplement introduced the Drow of Lolth monster stat blocks. How D&D approaches the Underdark and its inhabitants going forward, however, will remain to be seen.

We’ll be keeping a close eye on what comes out of this UA in the days ahead, but it will likely be several months before we learn what new book (if any) these subclasses will be published in.

In the meantime, you can check out all the material for yourself via the Unearthed Arcana page or download the PDF directly. Player feedback opens on August 27th, 2026.

Below is also an interview from the official D&D YouTube channel featuring an interview with designer Leon Barillaro.

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