New D&D Underdark Sourcebook Likely Coming in Late 2027

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If you really want to know what’s coming next for Dungeons & Dragons, there are few better place to look than Wizards of the Coast’s ongoing Unearthed Arcana playtests. We knew for example, that both Ravenloft and Dark Sun books were coming long before they were officially announced due to to several major UAs.

Now, all signs are pointing downward to a new D&D Underdark supplement. That’s because we’ve just seen back-to-back releases of two subterranean playtest packets: Underdark Options and Underdark Options 2 . This suggests that Wizards of the Coast is indeed laying the groundwork for a major return to the realms below.

So is the writing on the cavern wall or is something else brewing in the darkness? Below, we go deep and look at why a new D&D Underdark supplement is likely in the works.

What will the new D&D Underdark book be about?

To be clear, Wizards of the Coast has not officially confirmed that a new Underdark supplement is in development and no such product is listed for the 2026 and 2027 roadmap of upcoming D&D books. That being said, based on what we’ve seen in the two Underdark playtests released in August and September 2026, it’s likely we’ll be getting one (or more) books with the following player and GM-facing content:

• New Subclasses: So far we’ve seen six subclasses: Path of Unlight Barbarian, Freedom Domain Cleric, Circle of Spores Druid, House Agent Rogue, Faerzress Sorcery Sorcerer and Imaskarcanist Wizard. It’s possible some of these may be dropped and other subclasses added based on player feedback, but given how much effort goes into producing this content, they almost certainly will be published in a player-facing supplement. Notably five of these are brand new, while the Circle of Spores Druid is an update of a subclass that first appeared in 2018’s Guildmaster’s Guide to Ravnica and was later updated in 2020’s Tasha’s Cauldron of Everything, 
• New Species: We’ve also got five new species: the Deep Imaskari, Drider, Illithidkin, Kuo-toa and Myconid. All of these are completely brand new and have not appeared as playable species in any previous D&D 5E materials.
• New Magic: In the playtests, we’ve seen two new types of magic: Unlight (a type of unnatural, contagious magical radiance) and Faerzress (magical radiation left behind by the spider goddess Lolth). Both of these systems tie-in to several of the subclasses and it’s likely we’ll see new spells, magic items and mechanics built around them.
• New Lore: The playtest spends a significant amount of time covering the Imaskar Empire, an ancient nation of humans that abandoned the surface world thousands of years ago and settled in the Underdark, using Unlight to grow crops and protect their city. While Imaskar has been briefly touched upon in some D&D supplements over the years, there’s never really been a deep dive.
• A return of the Drow: The new Unearthed Arcana playtest material also covers dark elves and the city of Menzoberranzan. Notably, in D&D 5.5E drow became a playable race, rather than being represented as stereotypically evil. They were, however, eventually included as the “Drow of Lolth” stat block in the Adventures in Faerûn supplement, paving the way for their return in a dedicated supplement.
• New Feats: The playtest introduces the new Path of Ceremorphosis (similar to the Path of the Lich and Path of the Death Knight), which features the Mindflayer, a classic Underdark monster.

It’s possible that we may also see two books: a general supplement with character options and a tie-in campaign, much like how we saw the Arcana Unleashed supplement and the accompanying Arcana Unleashed: Deadfall adventure.

When will the new D&D Underdark book be released?

Based on past publications, there’s usually over a year from the first Unearthed Arcana playtest to the final product being released. With Ravenloft: The Horrors Within for example, the first UA was launched in May 2025, the product was officially announced in March 2026 and it finally hit shelves on June 2026.

If this new D&D Underdark book follow a similar development cycle, that means we can likely expect an official announcement in the early summer of 2027 and an official launch several months after in the late summer or early fall of 2027.

Final thoughts

It’s been over a decade since Wizards of the Coast released Out of the Abyss, the last supplement focused exclusively on the Underdark. Yet the setting remains as popular as ever, appearing in the Honor Among Thieves and Baldur’s Gate 3. Given that, it’s not surprising that the Underdark has resurfaced for D&D 5.5E.

We’ll be keeping a close eye on this possible new product in the days ahead and will update this page with new information as it’s made available.

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