It is the sixth work in a series of eight linked modules unofficially referred to as the Sunless Citadel adventure path. It consists of The Sunless Citadel (2000), The Forge of Fury (2000), The Speaker in Dreams (2001), The Standing Stone (2001), Heart of Nightfang Spire (2001), Deep Horizon (2001), Lord of the Iron Fortress (2002), and Bastion of Broken Souls (2002).
Centuries ago, the desmodus—bat-like humanoids inhabiting the Underdark—fought the drow in a war which threatened to destroy them. They sealed off their home caverns by re-routing a lava flow, destroying the drow city in the process. Nearly everyone assumed that the entire desmodu race had been destroyed.
Three months ago, an earthquake re-opened a path to the desmodus' domain, unveiled the lost drow city, and sparked conflict between the desmodus and their former trading partner, a colony of salamanders. The salamanders have struck an alliance with beholders who have taken up occupancy in the drow city. This in turn has led to political conflict within desmodu society as differing political factions disagree over the best way to handle the new threat.
The player characters descend into the Underdark and reach the ruins of a drow city, now occupied by beholders who have taken desmodu slaves. The desmodus lead them to an enclave of their people, leading to a murder investigation. Next, they lead an attack on a lair of salamanders. Alogn the way, they encounter rival factions of desmodu, each with their own agenda.
Deep Horizon was written by Skip Williams, with art by Brom and David Roach.
The module was previewed at Gen Con 2001, held from August 2-5 of that year..
On January 22, 2013, Deep Horizon was given a digital re-release at DriveThruRPG, and as of November 2020 was rated an electrum best seller at the site.
Influence on other works
Deep Horizon is the sixth in a series of eight adventure modules: The Sunless Citadel (2000), The Forge of Fury (2000), The Speaker in Dreams (2001), The Standing Stone (2001), Heart of Nightfang Spire (2001), Deep Horizon (2001), Lord of the Iron Fortress (2002), and Bastion of Broken Souls (2002). The concept of a series of linked adventure modules taking a character from level 1 to 20 would be come to be known as an "adventure path", a term first used by James Wyatt to describe this series in an interview in Dragon #281 (Mar 2001). Dungeon Magazine went on to publish its own adventure paths beginning in Dungeon #97 (Mar/Apr 2003). Following Dungeon's closure in 2007, adventure paths formed a core feature of Paizo Publishing's Pathfinder product line, which at one point surpassed Dungeons & Dragons in sales.
This adventure module introduced the desmodu to Dungeons & Dragons, later appearing in Monster Manual II (3e) (2002).
Kevin Kulp described Deep Horizon as an oldschool-style adventure module, focusing on exploration and combat. He described occasional complaints that the initial adventure hooks were lackluster, but the adventure itself was fun and offered flexibility for the DM to insert their own content.
|Sunless Citadel series|
|The Sunless Citadel • The Forge of Fury • The Speaker in Dreams • The Standing Stone • Heart of Nightfang Spire • Deep Horizon • Lord of the Iron Fortress • Bastion of Broken Souls|
|Dungeons & Dragons 3.0|
|Player's Handbook • Dungeon Master's Guide • Monster Manual • Dungeons & Dragons Adventure Game|
|Arms and Equipment Guide • Book of Challenges • Book of Vile Darkness • Defenders of the Faith • Deities and Demigods • Enemies and Allies • Epic Level Handbook • Fiend Folio • Ghostwalk • Hero Builder's Guidebook • Living Greyhawk Gazetteer (Dungeons & Dragons Gazetteer) • Manual of the Planes • Masters of the Wild • Monster Manual II • Oriental Adventures • Psionics Handbook • Savage Species • Song and Silence • Stronghold Builder's Guidebook • Sword and Fist • Tome and Blood|
|The Sunless Citadel • The Forge of Fury • The Fright at Tristor • The Speaker in Dreams • The Standing Stone • Return to the Temple of Elemental Evil • Heart of Nightfang Spire • Deep Horizon • Lord of the Iron Fortress • Bastion of Broken Souls • City of the Spider Queen|