Asteroid field

Asteroid field
Eros, a near-Earth asteroid 34 km long, by the NEAR Shoemaker probe · NASA/JPL/JHUAPL (color version published at Planetary Society), Public domain, Wikimedia Commons

Tumbling rock from pebbles to mountains, spread over more space than any eye can hold. Miners, smugglers and hermits hollow out the big ones, sensors lie, and a careless pilot meets a rock at the speed of a bullet.

Light
Dim
Going
Hard

Hear it

Hazards

  • Vacuum. No air at all: an unprotected person stays conscious for about ten to fifteen seconds, the moisture on the tongue boils, and death follows within minutes. A suit, a helmet that seals and an air supply are the price of every step. D&D 5e: With no breath to hold, a creature without air gains 1 Exhaustion level at the end of each of its turns until it can breathe; it then loses all the Exhaustion it gained this way. Starfinder 2e: Vacuum (GM Core): no breathable air, so the creature suffocates, and it takes minor bludgeoning damage (1d6 to 2d6) every minute; with no propulsion it is untethered. Armour environmental protections cover vacuum for a number of days equal to the armour's item level (minimum 1). Archives of Nethys
  • Weightlessness. Nothing falls. A person drifts in the direction they last pushed, tools float away if not tied down, and a fight is a matter of handholds. D&D 5e (House rule): House rule: a creature without a Fly Speed moves only by pushing off a surface, at its Speed in a straight line, until it meets another. Each attack it makes without a handhold has Disadvantage unless it has trained for weightlessness. Starfinder 2e: Zero gravity (GM Core): creatures are clumsy 1, off-guard and untethered; they move by Push Off from something their size or larger, or with propulsion. They lift and carry ten times as much, and thrown ranges are multiplied by 10. Archives of Nethys
  • Micrometeoroids. With no air to burn them up, grains of rock and metal arrive at many kilometres a second. Most are dust; now and then one punches a hole in a suit or a dome. D&D 5e (House rule): House rule: once a day outside, roll a d20; on a 1 a random creature's suit is holed. Patching it takes an action and a DC 10 Dexterity check with tinker's tools; until then the creature is in vacuum.
  • Tumbling rock. Big rocks spin, slowly but with the mass of a hill. Landing on one is a matter of matching its turn; a careless approach is a collision. D&D 5e (House rule): House rule: matching a rock's spin to land or dock takes a DC 14 Dexterity check with vehicle (space) proficiency; on a failure by 5 or more the craft takes 4d10 Bludgeoning damage.

What may happen

  1. Two rocks graze each other silently in the distance, and a cloud of gravel spreads toward the ship.
  2. A hermit's hollowed rock hails the ship and asks for news, and for coffee.
  3. A claim beacon warns that this rock belongs to a mining outfit, and that trespassers will be fired upon.
  4. A ship-sized contact on the scanners vanishes when a rock passes in front of it.
  5. A dark rock turns out to be ice under a crust of dust: water for months.
  6. A mining crew of six works a nickel-iron rock, tethered to its surface like climbers on a cliff.
  7. Two prospectors argue over the radio about who planted the first beacon on a rock. Both ask the party to witness.
  8. The target rock is tumbling end over end. The pilot must match its spin to land.
  9. There is almost no gravity on the rock. Every step must be anchored, or a boot pushes the walker gently off into space.
  10. Drilling raises a slow cloud of dust that does not settle; it hangs round the rock for hours like a halo.
  11. A hollowed rock has been turned into a home, with a door set in the stone and a window box of herbs behind the glass.
  12. An ore tug crawls by, pushing a rock the size of a house toward the refinery, its crew waving from the cab.
  13. The local channel is full of miners swapping jokes, prices and the scores of a game played three stations away.
  14. A drill head floats free beside a rock, its tether cut clean. Its owner would pay to have it back.
  15. An old survey beacon still blinks on a small rock, listing its minerals in a format thirty years out of date.
  16. A bar in a hollow rock serves drinks in squeeze bulbs. The regulars push off the walls to reach the counter.
  17. A large rock drifts between the ship and the sun, and the light through the viewports dims and returns.
  18. A big rock has been hollowed and set spinning. Inside, its miners walk on the curved wall in something like gravity.
  19. A mass driver on a rock flings buckets of ore toward a distant catcher, one every few seconds, in perfect silence.
  20. Sealed crates tumble among the rocks, freshly dumped. Someone was in a hurry to be rid of them.
  21. An empty suit is tethered to a rock, its visor open to space, its oxygen gauge at zero.
  22. A broken rock shows bands of bright metal in its face, crossed by a criss-cross pattern like frost on a window.
  23. The assay office on the refinery rock has a queue of miners and one assayer, a sharp-eyed woman who trusts nobody’s samples.
  24. The radar screen is so crowded with rocks that a real ship could hide among them and nobody would know.
  25. A miner has found a lump of ice in a rock and sells shaved water ice by the litre, flavoured with whatever she has.

Adventure hooks

  1. A hermit offers a map of a safe route through the field in exchange for a message carried home.
  2. A mining claim has been jumped, and the claim-jumpers have taken the original miners hostage.
  3. One rock is not tumbling: it holds its attitude perfectly, as if something inside steers it.
  4. A smuggler's cache is hidden in a hollow rock, and three crews have a third of the map each.

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, 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, Lava foundry

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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