Lava foundry

Lava foundry
Lava fountains on the lava lake inside Halemaʻumaʻu crater, at the summit of Kīlauea, Hawaii, September 2021 · USGS Hawaiian Volcano Observatory, Public domain, Wikimedia Commons

A factory on stilts over a sea of lava: furnaces, cranes and assembly halls on a steel platform that creaks in the hot wind, lit orange from below. Ore comes in by barge across the molten rock, and war machines go out the other end, finished or not. Near the edges the heat kills in minutes, ash falls without end, and the lowest decks glow when the lava rises. The lines may still be running, whether or not anyone is left to give the orders.

Light
Lit
Going
Slow

Hear it

Hazards

  • Lava sea. Molten rock as far as the haze lets anyone see, crusted with black plates that crack and glow. It flows, slowly in the open and fast in a channel; its heat burns at a distance, and nothing that falls in comes out. D&D 5e (House rule): House rule: a creature within 3 m (10 ft) of open lava without cooled protection takes 1d10 Fire damage at the start of each of its turns. A creature that enters lava or starts its turn in it takes 10d10 Fire damage. Starfinder 2e: Lava flows (GM Core): lava usually moves 5 to 60 feet per round over normal ground, and up to 300 feet per round in a steep tube or channel. Its heat deals minor fire damage before it touches anyone, and immersion deals massive fire damage each round. Archives of Nethys
  • Creaking gantries. The platform flexes in the hot wind: bolts shear, plates buckle and walkways sag over the lava. Most of the creaks mean nothing; the people who worked here learnt which ones did. D&D 5e (House rule): House rule: when a gust hits, a creature on an open walkway makes a DC 12 Dexterity saving throw or has the Prone condition. When a walkway gives way, each creature on it makes a DC 14 Dexterity saving throw to catch a rail; on a failure it falls to the deck below and takes Falling damage, or into the lava where there is no deck.
  • Searing heat. Hot enough to melt lead. Electronics fail within hours, and only active cooling, at a great cost in power, keeps anyone alive. D&D 5e (House rule): House rule: a creature or device without cooled protection takes 10d10 Fire damage at the start of each of its turns. A cooled suit protects for as many hours as its power lasts; Fire immunity protects the wearer, not the suit's electronics. Starfinder 2e: Incredible heat (GM Core, 60 °C / 140 °F or hotter): fatigued after 2 hours of travel and moderate fire damage (4d6 to 6d6) every minute. Starfinder has no band beyond this one; a superior thermal capacitor is the least a visitor needs. Archives of Nethys
  • Eruption. A vent opens or a plume fountains: lava floods a valley, and sulphur and rock rain down far around. The ground is never quite the same two days running. D&D 5e (House rule): House rule: a creature caught by falling debris makes a DC 15 Dexterity saving throw, taking 4d10 Bludgeoning damage on a failure or half as much on a success. A creature that enters lava or starts its turn in it takes 10d10 Fire damage.

What may happen

  1. The whole platform creaks in the hot wind, a slow complaint of steel that never quite stops.
  2. The lava lights everything from below: faces, girders and smoke all glow orange from underneath.
  3. A crane swings a ladle of molten metal across the gangway, on a schedule nobody has stopped.
  4. A war machine frame hangs in its cradle, half armoured, its weapon mounts empty and its sensor lit.
  5. Fine ash settles on every rail and sleeve, grey with flecks that still glow.
  6. A section of walkway has fallen, leaving a three-metre gap over the lava.
  7. A horn sounds the change of shift for workers long gone, and the conveyor lurches forward.
  8. The foreman’s office hangs above the floor in a glass box, its production board still counting units nobody collected.
  9. A ladle tips somewhere overhead and a spray of slag rattles across the roof.
  10. Heat shimmer bends the far end of the hall, so the machines there seem to sway.
  11. A test range at the platform’s edge is lined with scorched targets, and one turret still tracks movement.
  12. A bubble the size of a shuttle swells on the lava sea and bursts, flinging gobbets against the pylons.
  13. A coolant line hisses white vapour across a stair; the frost on the rail is gone within a second.
  14. A row of heat-warped lockers, each with a name tape and a photograph curling at the edges.
  15. One of the pylons groans and drops a few centimetres; the floor tilts toward the lava.
  16. The assembly line still runs, fitting arms to torsos and sending them, finished or not, to the loading bay.
  17. A heap of rejected war machine parts lies by a chute; a servo in it still turns, slowly.
  18. An empty ore barge creeps across the lava on its cable, heading for the dock.
  19. Sulphur fumes roll up through the grating when the wind turns.
  20. Sirens wail, and blast doors begin to close along the main hall, one after another.
  21. The control tower’s screens show a production order: three hundred machines, a delivery date, and no buyer’s name.
  22. The lava sea rises against the lowest deck, and the bottom stair begins to glow.
  23. Heat suits hang on a rack, their silvered faces blackened.
  24. The wind pulls threads of volcanic glass from the spray of the lava, and they drift by like golden hair.
  25. Fresh prints in the ash along a catwalk: large, heavy and three-toed.

Adventure hooks

  1. A broker wants the last war machine off the line before its buyer comes to collect it.
  2. The foundry’s control system is still filling an order for a war that has ended, and switching it off trips its defences.
  3. A welder’s daughter wants her mother’s locker emptied, and it hangs above the lowest deck.
  4. The pylons are failing one by one, and the company has already sold the foundry for scrap, with the scrappers already aboard.

Who and what is met

Each is an SRD stat block under another name, as game masters reskin them.

Other places among the stars

Orbital station, Derelict ship, Colony outpost, Precursor ruin, Asteroid field, Gas giant orbit, Deep space relay, Terraforming works, Prison hulk, Research lab, Crashed freighter, Nebula, Neon city, Junktown, Spaceport, War front, Alien hive, Living ship, Undersea base

This work includes material from the System Reference Document 5.2.1 ("SRD 5.2.1") by Wizards of the Coast LLC, available at https://www.dndbeyond.com/srd. The SRD 5.2.1 is licensed under the Creative Commons Attribution 4.0 International License, available at https://creativecommons.org/licenses/by/4.0/legalcode.

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