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The Incandescent Grottoes
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The Incandescent Grottoes


A bubbling stream cascades into a hole in the earth, leading to a series of underground watercourses and scintillating grottoes. Adventurers who delve within may discover odd mosses and fungi, a ruined temple complex, and the lair of a crystal-eating dream dragon.

A classic expedition into the Mythic Underworld for characters of 1st to 2nd level.

  • 57 keyed areas, rumour table, loot summary, dungeon background info, suggestions for expanding the dungeon.
  • Keyed in a quick-reference, bullet point format.
  • Statted for Old-School Essentials (B/X), usable with any vintage adventure game.
  • Unlabelled map included for VTT use.
The Incandescent Grottoes can be linked with The Hole in the Oak to form a large, 3 level dungeon with over 115 keyed encounter areas!

The Incandescent Grottoes was awarded the coveted "The Best" rating by Bryce Lynch of!

Print version: A deluxe, sewn-binding hardcover edition of this book (+ free PDF) is available from Exalted Funeral, along with all of the other books in the Old-School Essentials line. Note that there is no print-on-demand edition of this book.

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Reviews (2)
Discussions (4)
Customer avatar
CHRISTOPHER T April 02, 2022 3:50 pm UTC
Would this be a good intro adventure for 2 kids aged 10 or do you need more players/older more experienced players?
Customer avatar
Necrotic G April 04, 2022 7:12 am UTC
The adventure's designed for a group of around 5-6 characters, so if you only have 2 players then it'd be advisable to have some retainers accompany them. In terms of player age, there are some gross / mild horror elements in the adventure (slime, oozes, disintegration), so it'll depend on your players' sensitivity to such topics.
Customer avatar
Michael A June 17, 2021 2:19 pm UTC
Are there any plans to post the labelled map for download similar to what is available for The Hole in the Oak? Great work on this module by the way!
Customer avatar
Necrotic G June 17, 2021 3:06 pm UTC
I'm not quite sure what you mean, I'm afraid. Unlabelled maps for VTT use are provided for both adventures, but labelled maps aren't provided as separate files (they're in the PDFs, of course).

Glad you're enjoying the adventure!
Customer avatar
Michael A June 24, 2021 4:48 pm UTC
For clarification: When downloading Hole in the Oak here on DriveThru I downloaded three files: PDF, the gridded map without labels, and the gridded map with labels and corresponding key numbers. I really enjoy the Grottoes inclusion of the map sections within the text, but also like having a map open that includes the labels and key numbers; when using the PDF for this purpose the map is broken up between pages.

This is just a minor thing because I can always just load the provided maps into an editor and slap the numbers and labels on top. Thanks again for the product! Your modules are setting a great standard for playability and table use.
Customer avatar
Necrotic G June 25, 2021 6:43 am UTC
Ah I see. Hole in the Oak doesn't include that file any more, hence the confusion. I guess I thought it served little purpose when the exact same content is included in the PDF (unlike the unlabelled map, which doesn't appear in the PDF). The PDFs are designed to be viewed in "two page view" mode, by the way (and automatically open in the mode), so you should see the whole map displayed together. If you want the map as a separate file, maybe just make a screenshot of those 2 pages of the PDF?
Customer avatar
Michael A July 08, 2021 1:31 pm UTC
Yeah it's no big deal, I haven't gotten the display to work exactly correctly but I just took the provided tabletop maps and added my own labels. Cheers!
Customer avatar
Wagner V March 22, 2021 5:21 pm UTC
Hello Gavin, this was probably asked before but, are there any plans of releasing print versions of this adventure and the other OSE Official Adventure Scenarios, to buy via Exalted Funeral?
Customer avatar
Wagner V March 22, 2021 5:54 pm UTC
Nevermind... I didn't read the description!

"Print version: A print edition of this adventure is being produced and will be available from the Necrotic Gnome publisher website (link in the sidebar) in the summer."
Customer avatar
Simon P March 07, 2021 4:19 pm UTC
Is it possible to get a gridless version of the map? The grid provided VTT map is impossible to align with any of the VTT software I use and suspect any VTT software.
Customer avatar
Necrotic G March 09, 2021 9:14 am UTC
We'll look into it. (It depends on whether the artist has a version without the grid or not.)
Customer avatar
Alex D March 13, 2021 1:15 am UTC
Hi! I bought it today and there is a gridless map! :-)
awesome content btw!!! Love it!!
Customer avatar
Alex D March 13, 2021 8:29 pm UTC
One thing I just realized after printing my version, is that monster stats block prints using weird characters. I guess I have issue with true type Fonts on my printer. Fixed it by printing as image (in my advanced print settings) and reprinting the pages that had stats.

Sharing here for people to pay attention.
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File Last Updated:
September 27, 2021
This title was added to our catalog on March 03, 2021.