5.2. Planetary atmosphere

The planetary atmosphere will not affect a PC's personal characteristics as such, but he may obtain certain advantages or disadvantages from living in a given atmospheric type during his formative years:

1d20

Roll Effect of Native Atmosphere

on Player Character

Modifier

1

Managed atmosphere: The PC has lived in a dome city, IRSOL Star city, etc., because the external atmosphere is unbreathable (too thin, excessively contaminated with dust or toxic compounds, or even vacuum). Conditions within the protective environment are carefully controlled and monitored to maximize favourable factors. There is a fairly good chance that dome cities, space cities, and similar installations in vacuum or near vacuum conditions are maintained at pressures significantly below 760mm Terran standard pressure. This minimizes the effects of sudden decompression from sudden blow outs 'bends,' excessive loss of breathable atmosphere, and so forth.

PC would have a 35% chance of developing expanded lung capacity and will be able to breathe efficiently in atmospheres with Oxygen pressures as low as 50mm IPP.

2-3

Low pressure atmosphere: The PC is a native of a planet with atmospheric pressure under 500mm, but with oxygen levels at least 75mm. He will have expanded lung capacity and can breathe effectively when oxygen pressure in the lungs is as low as 40mm IPP, Such an atmosphere is equivalent to high altitude conditions on Terra.

PC will evidence adaptations similar to those of Indians living high in the Andes Mountains. Relative immunity to hypoxia when oxygen pressures are low is exchanged for distinct discomfort in dense atmospheres. When atmospheric pressures exceed 1000mm, excessive fatigue will occur because the PC's metabolism will 'burn' inspired oxygen too efficiently and may exhaust body energy reserves more quickly than normal. Oxygen pressures over 500 IPP in the lungs will be dangerously toxic.

4-5

Low pressure atmosphere, with contaminants: The PC is a native of a planet similar to that described for No. 2, above, only the atmosphere will be characterized by significant concentrations of dust or toxic gases.

PC will evidence greater tolerances of such contaminants than normal for off-planet types of the same or similar races, Alternatively he will be expert in the use of breathing apparatus, protective clothing, and recognition of hostile conditions. In the first instance, the PC will be 'adapted' to his environment (No, 4 result on the roll) and evidence similar adaptations as outlined in No 2, above, with the addition of higher tolerance levels to contaminants. PC normally lives in a 'managed atmosphere' but can tolerate external conditions 35% of the time, as outlined in No. 1 above, but without special tolerance to contaminants.

6-13

Standard pressure atmosphere.

PC is used to an atmosphere of more or less Terran quality, with pressures from 500mm to 1000mm at ‘sea’ level. His oxygen tolerance range is 60mm to 400mm IPP in the lungs.

14-15

Standard pressure atmosphere, with contaminants.

PC lives in an atmosphere more or less as described for standard pressure atmospheres, only excessive contaminants are also present. A No. 14 result means that the PC is somewhat adapted to these contaminants and bas a higher than normal tolerance. A No. 15 result means that the PC must use some form of protective measures (filters, gas masks, etc.) when contaminant concentrations are high. In both instances, the PC will be expert at detecting and dealing with adverse conditions when they do occur, which is generally on a sporadic rather than chronic basis. PCs in No. 15 conditions will likely live in sealed or filtered homes and use similar mobile units to minimize risks.

16-17

Moderately high pressure atmosphere.

PC lives in an atmosphere up to 2000mm pressure. His oxygen tolerance is 75mm to 550mm IPP in the lungs. Low pressure atmospheres are not particularly comfortable, and fatigue mat' set in quickly in low oxygen environments.

18

Moderately high pressure atmosphere.

PC lives in an atmosphere as described in No. 16, but significant atmospheric contaminants are present. He bas a 50% chance of higher tolerance levels. See No. 12-14 for general guidelines on handling contaminant problems.

19

High pressure atmosphere.

PC lives in an atmosphere with pressures in excess of 2000mm pressure. His oxygen tolerance is 90mm to 800mm IPP in the lungs. Low pressure atmospheres are distinctly disagreeable, while standard atmospheres are not comfortable. There is a 75°/ chance of atmospheric contaminants, with a 50% chance that a PC bas higher tolerance levels. See No. 12-14 for general guidelines on handling contaminant problems.

20

Exotic atmosphere: Very unusual concentrations of constituent atmospheric gases occur on the PC's home planet.

50% chance that the PC is adapted to these conditions as outlined in No. 14-15. If not adapted, appropriate precautions must be taken. Pressures tan be modified as the StarMaster desires.

A fair degree is 'tailoring' of home planet atmospheres will be required. This tan be done by the StarMaster, or the player tan be entrusted with the task. The entire section 15.8 on Breathable Atmospheres should be consulted when designing the atmosphere. It should be noted that a PC is either a full 'native' whose race evolved on the planet or else a 'native-born' colonial whose people either have adapted to local conditions or are in the process of adapting. Where adaptation is not complete, a PC will not have the capacity of truly native life forms to survive (or at least thrive) in the worst conditions that might exist.

Tell me more.

[previous step]

[back to top]

[next step]