In hard Vacuum unsuited: hold breath CON rounds, then Fort saves vs ebullism (1d6/round + Sickened) and suffocation.
A character exposed to hard Vacuum -- a hull breach, an airlock failure, a
suit puncture, or simply being pitched out an airlock -- is dying on two
clocks. They can hold their breath for a number of rounds equal to their
Constitution (minimum 2). Each round beyond that, they make a Fortitude save
(DC 15) or take 1d6 damage as their body fluids begin to vaporize (ebullism)
and gain the Sickened condition; failing by 5 or more drops them unconscious.
After Constitution + 2 rounds without air, they suffocate and begin dying
(see Bleeding (Unconscious at 0 HP)). A punctured suit loses its seal; the character or an
adjacent ally can patch it with a Reflex save (DC 15) or a Mechanics check as
a standard action. The only real fix is to re-pressurize or don a sealed
suit. Constructs do not breathe and ignore the suffocation clock.
Rules Reference
Field
Value
Duration / Default Formula
until re-pressurized or sealed; ticks each round unsuited
Duration / Type
variable
Prevented By
Sealed suit / vac-rated armour, Construct physiology (does not breathe)
Prevents
Speech, Sound-based communication
Stacking
replace
Effects
description: After held-breath rounds: 1d6 ebullism damage per failed Fort save.
Field
Value
description
After held-breath rounds: 1d6 ebullism damage per failed Fort save.
modifier
-1d6/round
target
hp
description: Fortitude save DC 15 each round beyond held breath; fail by 5+ = unconscious.
Field
Value
description
Fortitude save DC 15 each round beyond held breath; fail by 5+ = unconscious.
modifier
fortitude-repeat
target
saving-throw
description: Gains Sickened while exposed (body fluids vaporizing).
Field
Value
description
Gains Sickened while exposed (body fluids vaporizing).
modifier
sickened
target
skill-check
description: After CON + 2 rounds without air, suffocates and begins dying (COND-BLEEDING).
Field
Value
description
After CON + 2 rounds without air, suffocates and begins dying (COND-BLEEDING).
modifier
suffocate
target
condition-trigger
Remove Conditions
description: Re-pressurize the area or move into a pressurized compartment.
Field
Value
description
Re-pressurize the area or move into a pressurized compartment.
description: Don a sealed suit, or patch a punctured suit with a Reflex save (DC 15) or Mechanics check.
Field
Value
description
Don a sealed suit, or patch a punctured suit with a Reflex save (DC 15) or Mechanics check.
description: Fortitude saves each round sustain the character until air is restored.
Field
Value
description
Fortitude saves each round sustain the character until air is restored.