Space Patrol: Atmosphere

Mar 19, 2015
đź“• 4 min.

The effects of nonstandard atmospheres depend on two factors: pressure and composition. Both are summarized below, though details (like exact pressures and chemicals) are ignored.

Atmospheric Pressure

Vacuum/Trace: You can’t hold your breath in vacuum – and you may rupture your lungs if you try (1d of injury). If you exhale and leave your mouth open, you can operate on the oxygen in your blood for half the time listed under Holding Your Breath (p. B351). After that, you begin to suffocate (see Suffocation, p. B436).

Very Thin: The air is too thin to breathe. Earth’s atmosphere becomes “very thin” above 20,000 feet. If you lack protection (e.g., the Doesn’t Breathe advantage, or a respirator and oxygen tanks), you suffocate. Vision rolls are at -2 without eye protection.

Thin: Thin air is breathable if oxygen is present in Earthlike percentages, but it is hard on unprotected individuals. Increase all fatigue costs for exertion by 1 FP. Vision rolls are at -1 without eye protection. Finally, anyone who breathes thin air for an hour or more must check for “altitude sickness.” Make a daily HT roll at +4. Critical success means acclimatization – do not roll again. Success means no effect today. Failure means headaches, nausea, etc., giving -2 to DX and IQ. Critical failure means the victim falls into a coma (p. B429) after 1d hours. Roll against Physician skill once per day to revive the victim before he dies.

Normal: Within a human-tolerable range. No effects.

Dense: The air is breathable, with some discomfort: -1 to all HT rolls, unless you have a pressure suit. If the air contains more than 50% oxygen, you must wear a “reducing respirator” that lowers oxygen partial pressure, or suffer -2 to DX due to coughing and lung damage.

Very Dense: As “dense,” but a reducing respirator is required if the air is more than 10% oxygen. After spending any time in a Very Dense atmosphere, you must undergo decompression for 48 hours. If you fail to decompress slowly enough, make a HT roll. Critical success means no ill effects. Success means severe joint pain, causing agony (see p. B428); roll vs. HT hourly to recover. Failure means unconsciousness or painful paralysis; roll vs. HT hourly to regain consciousness, with each failure causing 1d of injury. Once conscious, you suffer joint pain, as described above. Critical failure results in painful death. Recompression to the highest pressure experienced lets you roll at HT+4 every five minutes to recover from all effects short of death.

Superdense: As “very dense,” but the atmospheric pressure is so great that it can actually crush someone who is not native to it, unless he has Pressure Support or an armored suit that provides this advantage; see Pressure (p. B435). Such atmospheres are often toxic, which presents a separate problem. You must also decompress after exposure, as for Very Dense, but the time required is increased to 120 hours (5 days).

Anyone with Pressure Support 1 can ignore the effects of atmospheres up to Very Dense, but not Vacuum/Trace. Pressure Support 2 or higher ignores Superdense as well. Vacuum Support provides total protection from Vacuum/Trace atmospheres. Space Patrol standard uniforms provide both Pressure Support 1 and Vacuum Support with the included gloves and flexible helmet.

Atmospheric Composition

Corrosive: The atmosphere reacts with exposed flesh. Those with the Sealed advantage are safe. Small concentrations in otherwise breathable air require a roll at HT to HT-4 every minute to avoid 1 point of corrosion damage. Victims suffer coughing (see p. B428) after losing 1/3 their HP, blindness after losing 2/3 their HP. Atmospheres made up mostly of corrosive gases have effects comparable to immersion in acid (see p. B428) and count as suffocating.

Toxic: The atmosphere is poisonous. Individuals without respirators, Doesn’t Breathe, Filter Lungs, etc. are susceptible. Ordinary airborne industrial pollutants might require a daily HT roll to avoid 1 point of toxic damage. Lethal gases would call for a HT-2 to HT-6 roll every minute to avoid 1 point of toxic damage. If such gases make up most of the atmosphere, they inflict at least 1d toxic damage per 15 seconds (no resistance possible) and count as suffocating.

Suffocating: The atmosphere is unbreathable. For humans, this means it lacks oxygen. Those without Doesn’t Breathe or an air supply start to suffocate (see p. B436).

The Space Patrol standard uniform grants Sealed with the included gloves and flexible helmet.

Explosive Decompression

When an area suddenly goes from normal pressure to little or none (a “blowout”), body fluids boil, blood vessels rupture, and eardrums pop. Take 1d of injury immediately, and roll vs. HT to avoid decompression effects as for Very Dense atmosphere, p. 00. Also roll vs. HT+2 for each eye; failure means One Eye or Blindness, as appropriate. Finally, roll vs. HT-1 to avoid Hard of Hearing. Use the Duration of Crippling Injuries rules (p. B422) to determine how long these disadvantages last. Vacuum Support protects against these effects.