The Core XII

 Discover what the Universe of Strings has in store for you...

The City of Strings

Be welcome, planeswalker, to the greatest bastion of knowledge of the current era! Discover the many secrets guarded within the City of Strings itself!

Meet the Threadmasters that lead our organization, fight the powerful monsters that threaten it, and save Ariadne herself from the clutches of strife and betrayal in this extra large entry!

This is our full May 2024 release, with a length of 125 pages of lore, art, encounters, and game mechanics ready to be used in your D&D games. It has a surplus of monsters and items! 

This entry has a pretty big amount of CR 30 creatures and beyond! It is our best (and longest!) work yet.


The Tectonic Netherdepths

Delve into the depths of the world and discover the long forgotten halls of an ancient civilization! Explore even deeper, through the Undermountain, and find the monstrosities that dwell in these underground caverns!

Traverse the darkness with your fellow adventurers, fight the cults of the old gods, and unveil the secrets of creation itself, all the while being stalked by the red eye of the Beast!

This is our full April 2024 release, with about 80 pages of lore, art, encounters, and game mechanics ready to be used in your D&D games. It has a surplus of monsters and items!


The Emerald Crown

Sail to the Fae-touched Isles, an archipelago of mystical creatures, knights devoted to nature, and a court of dryads and faeries. 

Discover the secrets of the Emerald Queen, ruler of both dark and light fae, who mysteriously disappeared, leaving her kingdom in strife and chaos. Encounter the great tricksters of fairy tales, battle the nightmarish monsters of the paledark, and piece together the last artifact that can bring peace to the land  the Emerald Crown itself!

This is our full March 2024 release, with about 90 pages of lore, art, encounters and game mechanics ready to be used in your D&D games.


The Last Bastion

Ascend to the floating city of Uldann, where elder magics of unimaginable power endure against the winds of time. A city-state of constructs, philosophy, and very turmoiled politics... Define the fate of this illustrious bastion of civilization as you discover an intricate plot taking place upon its ancient stones.

This sourcebook is our second longest work, challenging the description of "mini" we usually give them, grazing 100 pages! It is complete with a fully fledged storyline, interwoven with the many monsters, spells, items, feats and encounters you know and love. We hope you enjoy!

This is our full February 2024 release, with about 100 pages of lore, art, encounters and game mechanics ready to be used in your D&D games. 

Allfather's Ink

Delve into the ruined land of Midgard, where the corruption of the Mad God has transformed a once beautiful kingdom into a realm of horrors! Climb to the top of the Blackbark and confront Odin, the host of the nightmare!

This edition has been illustrated (and inspired!) by the amazing Kim Diaz Holm and his dark fantasy art! From top to bottom, this booklet is as much a D&D sourcebook as it is an art showcase of his incredible work. We are proud to say the graphic design and artwork is the best we have produced so far!

This is our full January 2024 release, with about 75 pages of lore, art, and game mechanics ready to be used in your D&D games.

Library of Underside

Delve into the Underside, a dungeon of ancient, cursed knowledge, aberrations from beyond the confines of reality, and deathless casters gone mad with the passage of centuries! Discover the secrets of Eternity's prison, the City of Strings itself, and the megastructure that hides beneath!

This entry has a surplus of magical items and monsters compared to most of our releases, reflecting the ancient riches and perils contained within the oldest, most primeval dungeon in our burgeoning D&D universe!

This is our full December 2023 release, with about 80 pages of lore, art, and game mechanics ready to be used in your D&D games. One of our longest and most ambitious entries!

The Rippling East

Travel to the Rippling East, a land of ancient kingdoms and divine dragons! Join the fight against the perilous Yokai and their terrible Oni Emperor, and discover the lands of the eastern kingdoms!

In addition to all the content you know and love from Ariadne's Codex, this edition has a surplus of monsters and magic items, to spice up your games with great variety of mechanics and encounters! This Deluxe Edition also contains a mini adventure: to Restore the Narak, that puts many of the monsters and mechanics found in the entry to use!

This is our full November 2023 release, a fan favorite, with about 90 pages of lore, art, and game mechanics ready to be used in your D&D games.

The Nova Cluster

Enter the Nova Cluster, a miniature galaxy in the Astral Sea, teeming with ancient artifacts buried in its asteroids, powerful Gaardmen, and unscrupulous spacefaring pirates! Fight the creatures born of the Eminent Star and discover the truth behind the power of Gyreon, God of Order!

In addition to all the content you know and love from Ariadne's Codex, this edition has a surplus of monsters and magic items, to spice up your games with great variety of mechanics and encounters!

This is our full October 2023 release, with about 70 pages of lore, art, and game mechanics ready to be used in your D&D games. Another fan favorite!


The Molten Crucible

Enter the Molten Crucible, a volcanic expanse teeming with ancient artifacts buried under rivers of magma, greedy warmongering devils, and relentless elementals of fire and lava! Discover nine devil cities, meet the Gods of the Crucible, and help resolve a tragic conflict of divine stakes!

In addition to all the content you know and love from Ariadne's Codex, this edition has extra storytelling and narrative content for you and your party to enjoy a unique, extraordinary D&D experience.

This is our full September 2023 release, with 70 pages of lore, art, and game mechanics ready to be used in your D&D games.


The Soulfrost Expanse

Venture into boreal forests, dazzling frozen heights, and the unknowable deep frost in the Soulfrost Expanse, an expansion of arctic goodness! Meet the Isark tribes, the Iceborn, and the terrible Herald of the Killing Frost, Yharel, the Elder Wyrm.

In addition to all the content you know and love from Ariadne's Codex, this edition has plenty of variant rules and other experimental content for you and your party to enjoy a unique, unusual D&D experience, including a new class! Get the latest Shaper version on our Free Release Library, under Entries.


This is our full August 2023 release, with 70 pages of lore, art, and game mechanics ready to be used in your D&D games. 


 Citadel of Radiance

Discover the holy citadel of Lyntas: walk its glorious streets, see angels living among men, and learn its dark secrets... Meet the starfolk, born of the cosmos, and discover a conspiracy led by the Wielder of Anarchy himself!

This is our second ever entry into the universe of the Codex of Strings, and it sorely needs a revamp. We are working on a remastered edition! A freshly revised, up to date version of this sourcebook will arrive... eventually. We are still very proud of this entry, however! It is a particularly wacky concept for a setting. Check it out!

This is our full July 2023 release, with 60 pages of lore, art, and game mechanics ready to be used in your D&D games. 


 Ichorous Peninsula

Venture into the perilous marshland of Selem: discover its harrowing history, aberrant monstrosities, and steadfast protectors. Delve into the Sombrian with Chief Sentinel Selena and find the secrets behind the Ichorous Corruption!

Our first ever entry! Since June, we have remastered this sourcebook to bring it up to speed with our current quality and length. We are very fond of it!

This is our full June 2023 release, with 70 pages of lore, art, and game mechanics ready to be used in your D&D games. 


Get The Deluxe Editions


Autumn Deal: The Dark Collection

Discover the Universe of Strings with its many eldritch and cursed settings ! Find yourself amid the dark marshes of Selem, in the heart of accursed Asgard, and in the depths of the material plane! The Threads of Divinity await! This promotion includes the following products: From our CORE XII settings: - The Ichorous Peninsula: Remastered Edition ($24.99) - The Library of Underside ($24.99) - Allfather's Ink ($24.99) - The Tectonic Netherdepths ($24.99) From our newest releases: - The Court of the Afterlife ($16.99) - Angels of Tartarus ($16.99) - Splinters of Death: Ultimate ($24.99) In addition, this promotion contains  Ariadne's SRD   V.1.3  for free! 110+ pages taken from all our entries, with updates and improvements to previous content, and much, much more. 

$49.99 $120.00

Deluxe Editions Promo Pack: Pick Any Two Releases!

For the most knowledge-hungry planeswalkers! Select our two Deluxe Edition releases that caught your eye the most, and get them both at a discounted bulk rate! Will you mix the hallowed boulevards of Lyntas with the murky waters of the Ichorous Peninsula? Or perhaps the frozen peaks of the Soulfrost Expanse with the fiery pits of the Molten Crucible? It's your choice! In addition, this promotion contains  Ariadne's SRD   V.1.3   for free!  110+ pages taken from all our entries, with updates and improvements to previous content, and much, much more.  Make sure not to accidentally submit the same choice more than once: delivery systems get confused easily!

$34.99 $50.00

Deluxe Editions Jumbo Pack: Pick Any Three Releases!

The very best deal we offer! Select the three Deluxe Edition releases that caught your eye the most, and get them all at a 50% off bulk rate! Will you mix the hallowed boulevards of Lyntas with the murky waters of the Ichorous Peninsula? Or perhaps the frozen peaks of the Soulfrost Expanse with the aberrations that stalk Midgard in Allfather's Ink? It's your choice! In addition, this promotion contains Ariadne's SRD V.1.3 for free! 110+ pages taken from all our entries, with updates and improvements to previous content, and much, much more.  Make sure not to accidentally submit the same choice more than once: delivery systems get confused easily!

$39.99 $80.00