Aetherial Expanse is a campaign setting for Dungeons & Dragons 5th Edition published by Ghostfire Gaming, themed after sails, cannons, empires and high piracy.
The eponymous Aetherial Expanse is a sea of aetherial liquid floating in the endless void of the Astral Plane, where portals leading to other planes regularly open and close. The aether is toxic to most creatures, except those that mutated to survive in the depths. In some places, the aether crystalises into aetherium, a material that can be used to power various magical devices. The Aetherial Expanse is dominated by two mighty nations from different planets of the Material Plane: the Karelagne Empire and the Kingdom of Ayris, whose galleons and privateers strike fear into the hearts of those foolish enough to cross them. Between these two nations are the free pirates of the Isle of Drakes.
The Aetherial Expanse was first introduced as the setting of Pirates of the Aetherial Expanse, a six-part adventure campaign published as part of Ghostfire Gaming's Fables line. In 2023, a crowdfunding campaign was held on Kickstarter to release the Aetherial Expanse as a full-fledged setting book.
This game contains examples of:
- Alien Sea: The Aetherial Expanse is named because its seas aren't made of salt water, but of aether, which looks like shimmering, liquid starlight. The sea of aether acts similarly to normal saltwater seas, but differs in several key aspects.
- Dowsing Device: When an aetherium dowsing staff is activated, if there's a deposit of aetherium (other than the staff) within 1000 feet of it, the staff responds by tilting toward it.
- The Empire: Both superpowers fighting over the Aetherial Expanse are oppressive institutions that kill without mercy to dominate, colonise and pillage the islands.
- Endless Daytime: Areas of the Aetherial Expanse with strong, consistent elemental activity, like the Isle of Drakes, live in perpetual daylight because the aether vapour in the sky glows brightly as it reacts with the power of the Elemental Planes. People who live here must become comfortable with sleeping in daylight.
- Fictional Currency: Most magic item traders deal only in aetherium, the rarest and most valuable form of aether in the Aetherial Expanse and beyond.
- Fire-Breathing Weapon: The flamethrower is a short-ranged gun that draws directly upon the flames of the Elemental Plane of Fire.
- Floating Continent: A thousand islands are said to float in the Aetherial Expanse.
- Merchant City:
- Thousands of merchant vessels swarm around Windcrown like biting flies around a cow. The Ayrissian crown longs to make it an interplanar hub of trade, where merchants from all corners of the cosmos can buy and sell their exotic wares, but at present it's got a long way to go.
- Port Majeure is a major trade port and a military hub for the Karelagne Navy and a handful of privateer vessels. Ayrissian merchant ships frequently dock here too, despite lingering tensions from the recently concluded war between Ayris and Karel.
- Lightning Gun: A coilgun channels magically generated electricity until it leaps from the coil like a bolt of lightning.
- Monster Organ Trafficking: When elementals are killed on the Astral Plane, their bodies coalesce into a mote of energy that can be used for various purposes. Hunting elemental beasts for their motes is acceptable; killing an intelligent elemental for this purpose is considered akin to cannibalism.
- Perpetual Storm: At the heart of the Aetherial Expanse lies the Maelstrom, an aetherstorm whose unending fury has given rise to countless legends.
- Playing Both Sides: Many privateers slip into true piracy, often by accepting letters of marque from both Ayris and Karel. Privateers who operate like this are usually caught and rightly hanged as pirates.
- Practical Currency: Aetherium, which is accepted as a black market currency, is valuable both because of its rarity and its use as an energy source or weapon.
- Privateer: Letters of marque issued by either the Ayrissian or Karelagne government permit privateers to freely prey upon merchant vessels and towns without fear of reprisal from the government which issued the letter, as long as they don't attack those who fly their employer's flag.
- Space Cold War: Two great nations battle for control of the Aetherial Expanse: the Kingdom of Ayris, a small realm on its own world that maintains its power through trade, and the Karelagne Empire, which dominates much of its home world and now seeks to spread its influence onto other planes. Even after their hot war ended, the rivalry has persisted, and their privateers constantly harass the other nation's merchant vessels.
- Taken for Granite: The corpses of those who die of aether poisoning harden entirely into aetherium crystal.
- Totalitarian Gangsterism: The Isle of Drakes is a haven for all pirates across the Aetherial Expanse. Together, they're powerful enough to hold the privateers and bounty hunters of Karel and Ayris at bay, but not organised enough to establish a permanent pirate realm.
- Weird Weather: Aetherstorms occur when a rare planar alignment causes portals to all four Elemental Planes to overlap. Magic explodes outward and is amplified by the aether in a feedback loop that creates a storm of thundering clouds, fist-sized hailstones, raining fire and quaking earth.
