Space Environment Quick Reference

Last Updated: 2026-01-16

Quick reference for space hazards. For full rules, see:
compiled/COMPILED_MODULE_PLAYER_RULES.md (Part VII - Space Environment)

Module Implementation Status

This is a rules-only reference document. Space environment rules are resolved manually by the GM using the tables below.

Feature	Status	Notes
Vacuum Effects	📖 Rules Only	GM applies damage and conditions manually
Radiation Hazards	📖 Rules Only	GM tracks saves and radiation sickness
Gravity Modifiers	📖 Rules Only	GM applies skill/speed modifiers
Atmospheric Hazards	📖 Rules Only	GM tracks affliction progression
Temperature Extremes	📖 Rules Only	GM applies damage per frequency
Scale Conversion	📖 Rules Only	Reference for mixed-scale combat
Survival Equipment	✅ In Compendium	Items in `tech-items` pack

Vacuum & Decompression

Vacuum Exposure Effects

When exposed without protection:

Hold breath for rounds = Constitution modifier (minimum 1)
Then begin dying (suffocation rules)
Take 1d6 bludgeoning damage per round (no save, no resistance)

Decompression:

All creatures take 3d6 bludgeoning damage immediately
Reflex save (DC 18) or be pulled toward breach

Result	Effect
Critical Success	Not pulled; act normally
Success	Pulled 5 ft toward breach
Failure	Pulled 10 ft; flat-footed until end of next turn
Critical Failure	Pulled 20 ft; prone and flat-footed

Breach Sizes & Seal DCs

Breach Size	Pull DC Modifier	Seal DC	Seal Time
Small (1 ft.)	-2	15	2 actions
Medium (5 ft.)	+0	18	2 actions
Large (10 ft.)	+2	22	2 actions
Massive (20+ ft.)	+5	28	2 actions

Vacuum Survival Checklist

Environmental seal active (armor/suit)
Capacity sufficient for mission duration
10-minute warning system functional
Backup oxygen available
Emergency beacon accessible
Rescue plan established

Extending Air Supply:

Rationing: DC 15 Survival check = +50% duration (must rest)
Sharing: Two creatures can share one suit's air at half duration each

Radiation

Radiation Levels & Effects

Level	Fort DC	Damage	Condition	Save Frequency
Low	15	1d4	Sickened 1	Per minute
Medium	18	2d6	Sickened 2	Per minute
High	22	4d6	Sickened 3, Drained 1	Per round
Severe	28	8d6	Sickened 4, Drained 2	Per round

Radiation Save Results

Result	Effect
Critical Success	No effect
Success	Half damage, no condition
Failure	Full damage and condition
Critical Failure	Double damage, condition +1 severity, Doomed 1

Radiation Sickness Stages

Stage 1 (1-2 failures): Sickened persists 1 day
Stage 2 (3-4 failures): Sickened persists 1 week; Drained 1
Stage 3 (5+ failures): Sickened persists 1 month; Drained 2; lose 1d4 HP/day

Radiation Protection

Protection	Effect
Standard Armor	+2 circumstance bonus to saves
Radiation-Shielded Armor	+4 bonus; reduces level by 1
Radiation Medication	Auto-succeed vs Low; +2 vs higher
Lead/Dense Barriers	Blocks Low; reduces others by 1

Treatment: Medicine DC 15 + (Radiation Level × 2), 1 hour

Critical Success: Remove all radiation conditions
Success: Reduce stage by 1
Failure: No improvement
Critical Failure: Condition worsens by 1 stage

Gravity

Gravity Categories & Modifiers

Category	Speed	Jump	Carrying	Athletics	Special Effects
Zero	Drift 10 ft	—	×10	-2 melee	Must push off surfaces; DC 18 to maneuver
Low (≤1/3)	Normal	×3	×2	+2 jump/climb	Thrown weapons ×2 range; ranged -2 beyond 1st increment
Standard	Normal	Normal	Normal	Normal	No special effects
High (≥2×)	×1/2	×1/2	×1/2	-2	Fatigued after 1 hour (Fort DC 18)
Extreme (≥5×)	×1/2	×1/2	×1/2	-2	1d6 damage/round; cannot stand from prone (DC 20); flying ends

Zero Gravity Maneuvers

Acrobatics or Athletics DC 18 to change direction or stop:

Critical Success: Move as intended; take other actions
Success: Move as intended
Failure: Continue drifting in original direction
Critical Failure: Begin spinning; flat-footed until stabilized

Atmospheric Hazards

Atmospheric Types & Effects

Type	Fort DC	Frequency	Primary Effect
Thin	15	Per hour	Fatigued (strenuous = 18 DC per 10 min)
Thick	15	Per hour	Sickened 1; ranged weapons -1 per increment
Toxic (Low)	15	1 min onset	Stage 1: Sickened 1 → Stage 2: Sickened 2 → Stage 3: Sickened 3, Slowed 1
Toxic (Medium)	20	3 rnd onset	Stage 1: Sickened 2, 2d6 → Stage 2: Sickened 3, 4d6 → Stage 3: Unconscious
Toxic (High)	25	1 rnd onset	Stage 1: 4d6, Sickened 3 → Stage 2: 8d6, Paralyzed → Stage 3: Death
Corrosive (Mild)	—	Per minute	1 acid damage
Corrosive (Moderate)	—	Per minute	1d4 acid damage
Corrosive (Severe)	—	Per round	2d6 acid damage
Corrosive (Extreme)	—	Per round	4d6 acid damage

Note: Standard environmental seals protect against Mild and Moderate corrosive atmospheres.

Temperature Extremes

Extreme Heat

Temperature	Damage	Frequency	Fort DC	Effect
Hot (95-115°F)	—	—	15	Per hour or Fatigued
Severe (116-139°F)	1d4 fire	Per 10 min	18	Damage on failed save
Extreme (140-179°F)	2d6 fire	Per minute	22	Damage on failed save
Burning (180°F+)	4d6 fire	Per round	25	Damage on failed save

Extreme Cold

Temperature	Damage	Frequency	Fort DC	Effect
Cold (40-0°F)	—	—	15	Per hour or Fatigued
Severe (-1 to -40°F)	1d4 cold	Per 10 min	18	Damage on failed save
Extreme (-41 to -80°F)	2d6 cold	Per minute	22	Damage on failed save
Freezing (-81°F or lower)	4d6 cold	Per round	25	Damage on failed save

Scale Conversion

Distance Scales

Starship Hexes	Personal Scale	Use Case
1 hex	200 feet	Close combat
1 hex	1,000 feet	Standard starship combat
1 hex	10 miles	Fleet action scale

Mixed-Scale Combat

Initiative & Timing:

1 starship round = 1 personal round
All combatants roll initiative normally
Ships and creatures act in initiative order

Personal Weapons vs Starships:

Cannot damage hull or internal systems
Can target exposed components (AC 12-20, HP 15-30)
Examples: Sensor array, external turret, thruster nozzle, viewport

Starship Weapons vs People:

Starship damage × 10 = Personal damage
Example: 2d4 starship damage = 20d4 personal damage
Cannot target individuals (50-foot minimum area)
All in area take damage (Reflex DC 20 for half)

Starship Collisions:

Creature takes 10d6 per starship speed
Starship takes no damage (unless creature is Gargantuan+)
Gargantuan+ creatures deal (level × 2) damage to ship

Exposed Components Targeting

Component	AC	HP	Effect if Destroyed
Sensor Array	15	20	System becomes Glitching
External Turret	18	30	Weapon disabled
Thruster Nozzle	16	25	Speed -1
Viewport	12	15	Breach (see Decompression)
Shield Generator	20	35	Shields drop by 1 arc
Comm Array	14	15	No long-range comms

Survival Equipment

Armor Environmental Seals

Seal Type	Duration	Radiation Bonus	Temperature Range
Basic	24 hours	+2 save	-40 to 140°F
Standard	72 hours	+4 save	-80 to 180°F
Advanced	1 week	+6 save	-150 to 300°F
Military	2 weeks	Immune to Low	-200 to 500°F

Emergency Equipment Quick List

Item	Effect	Level	Price
Emergency Bubble	1 hour vacuum protection	3	150 cr
Oxygen Canister	+8 hours air	1	25 cr
Radiation Medication	+4 radiation saves (1 day)	5	200 cr
Gravity Boots	Function in zero-G	4	300 cr
Thermal Suit	Resist extreme temps	6	500 cr
Emergency Beacon	Signal rescue (100-mile)	2	50 cr
Survival Kit	3 days supplies	1	25 cr

Breathing Apparatus

Type	Duration	Notes
Rebreather	4 hours	Filters Low toxins only
Oxygen Tank	8 hours	Compressed air supply
Recirculator	24 hours	Recycles exhaled air
Life Support Unit	72 hours	Full environmental support

Quick Procedures

Radiation Exposure Sequence

Enter radiation zone
Roll Fortitude save vs radiation DC
Apply damage and conditions based on result
Track failed saves for radiation sickness stages
Repeat saves per exposure frequency

Sealing a Breach

Make Crafting check vs Breach Seal DC (2 actions)
Critical Success: Breach sealed; can repressurize
Success: Partially sealed; pull DC reduced by 5
Failure: Breach not sealed
Critical Failure: Breach widens by one size category

Zero Gravity Movement

Push off surface (30 ft straight line)
Or use maneuvering thrusters (10 ft drift per action)
To change direction: Acrobatics/Athletics DC 18
On failure: Continue drifting in original direction
On critical failure: Begin spinning (flat-footed)

Quick reference - approximately 2-3 pages when printed