Aethel, the Sunken Core Inner Earth Sword & Sorcery Campaign Adventure Using both Castles & Crusades (C&C) and Night Shift: Veterans of the Supernatural Wars (NSW) Rpg

 So this blog entry picks right up from Tuesday, November 18, 2025  This campaign adventure uses the SIEGE Engine rules found in both Castles & Crusades and Night Shift: Veterans of the Supernatural Wars, making them highly compatible.The key difference is that C&C focuses on fantasy character classes, while Night Shift offers modern archetypes. The SIEGE Engine's core mechanic—rolling against the Challenge Base (CB) of 12 + the relevant Prime Attribute bonus for difficult tasks—remains consistent across both games. 

Campaign Setting: Aethel, the Sunken Core

The campaign is set within Aethel, a vast, unexplored subterranean realm located deep beneath the Earth's crust. This is not a place of friendly dwarves and tidy caverns, but a primordial, dangerous world of "Sword & Sorcery" adventure: lost civilizations, ancient magic, terrifying creatures, and competing factions vying for survival in the dim glow of a mini-sun.

• Atmosphere: Gritty, dangerous, survival-focused. Magic is rare and often perilous. Technology is anachronistic (lost Roman legions, ancient Atlanteans, cave-men).
• Central Hub: The Shattered City, a dangerous trading post built among the ruins of an ancient, petrified metropolis.

Character Integration (C&C and NSW)

Players can choose between classic C&C fantasy classes or Night Shift's modern archetypes, leveraging the SIEGE Engine's flexibility.

• Castles & Crusades Characters: Knights, Wizards, Rogues, etc., are assumed to be locals of Aethel, descendants of lost explorers, or explorers who found their way down from the surface.
• Night Shift Characters: Veterans, Academics, Techies, etc., represent a modern-day team that accidentally fell into Aethel through a portal or geological anomaly. Their modern knowledge and basic equipment will be highly valuable but often useless against the sheer strangeness of the Inner Earth.

Both groups must work together to survive and find a way back to the surface.

Adventure Arc: The Serpent Crown of X'othal

The primary conflict revolves around an ancient artifact, the Serpent Crown of X'othal, a powerful psychically-active relic that grants dominion over the realm's cold-blooded inhabitants (lizardfolk, dinosaurs, giant snakes).

The adventure is broken down into three parts:

Part 1: The Descent into Darkness

Goal: The characters must navigate the perilous vertical tunnel system (The Great Bore) to reach Aethel.

• Challenges:
  • Geological Hazards: Earthquakes, rockslides, and magma vents (use C&C/ NSW saving throws vs. danger/elements).
  • Stalkers: Feral troglodytes and giant spiders hunt the tunnels. Night Shift characters will find their firearms useful here, but ammo is limited (emphasize resource management).
  • The Guard Post: The remnants of a Roman legion, lost for centuries, guards the final passage into Aethel, demanding tribute or a fight.

Part 2: The Shattered City and Faction Play

Goal: Establish a base in the Shattered City, gather information on the Crown, and navigate local politics.

• Factions:
  • The Scaled Covenant: Lizardfolk who serve an ancient, unseen master, currently searching for the Crown.
  • The Atlantean Remnant: Decadent humanoids using advanced (magic-based) technology, believing themselves the rightful rulers of Aethel.
  • The Surface Scouts: A rag-tag group of explorers from the surface who have been trapped for years.
• Quests:
  • Information Gathering: Find the one sage who knows the Crown's location (requires social checks or espionage using NSW skills).
  • Resource Management: Trade modern goods (NSW players) or gold (C&C players) for essential supplies like medicine, light sources, and food.
  • The Arena: Participate in gladiatorial combat for the Atlanteans to gain prestige or freedom.

Part 3: The Temple of the Sunken God

Goal: Retrieve the Serpent Crown from the Temple of X'othal before the Scaled Covenant does.

• Location: An active, volcanic temple complex deep within a jungle swamp.
• Challenges:
  • Jungle Hazards: Acidic plants, quicksand, dinosaur encounters (use C&C monster stats).
  • Puzzle Rooms: Ancient Atlantean technology/magic traps and riddles (SIEGE checks for Intelligence/Wisdom).
  • The Final Boss: The High Priest of the Scaled Covenant has partially bonded with the Crown. The players must defeat him while the temple crumbles around them, threatening to collapse the entire region.

Conclusion

If the players secure the Crown, they must decide whether to use its power to force safe passage home, destroy it to save Aethel from tyranny, or simply try to escape the now-unstable Inner Earth. The adventure ends as they face the dangerous journey back to the surface.