Contagion damage only affects characters. Further, a contagion does not initially inflict numerical damage and cannot inflict critical injuries, but rather represents potential exposure and a variety of subsequently debilitating effects.
When a contagion is delivered by contact, an unwilling target is exposed with a successful melee or unarmed attack.
When a contagion is delivered by ingestion, a target is exposed when he consumes contaminated edibles or fluids.
When a contagion is delivered by injury, an unwilling special character is exposed if the lethal damage from a prepared attack with a contaminated weapon reduces his wound points by 1 or more (after damage reduction and resistance are applied). An unwilling standard character is exposed when he makes a successful Damage save by 5 or less. Alternately, either character type may be exposed with a prepared syringe and a successful Called Shot.
When a contagion is delivered by inhalation, an unwilling target is exposed when he breathes contaminated air, commonly because he’s failed a Fortitude save to hold his breath.
Contact- and inhalation-delivered diseases may be contagious. A character is exposed if he comes in contact with any person infected with a contact-delivered contagious disease, or lingers within 100 ft. of a person infected with an inhalation-delivered contagious disease for 10 rounds or more.
A heldA held character is vulnerable and may not move or take any non-free action except to attempt a full action Athletics (Str) check to escape the hold. This check possesses the Armor Check Penalty tag. , helplessA helpless character is vulnerable. Further, attacks targeting him within Melee Range gain a +4 bonus. Finally, he may be targeted with a Coup de Grace action., sleepingA sleeping character may take only passive actions and is also considered blinded and helpless. A character loses this condition immediately upon being touched, suffering any damage, or making a successful Notice/Awareness check., or unconsciousAn unconscious character is helpless and may take no actions. A character loses this condition after 2d4 full hours of sleep. target may be exposed to any contagion with 1 half action. This requires a ready method of delivery (i.e. an infected weapon, a syringe containing the contagion in solution, etc.). Contagion damage delivered in this fashion has the armor-piercingThis quality applies to weapon damage, reducing damage reduction. (all) quality.
Each exposed character incubates the contagion for its Primary Onset Time, after which he must make a Fortitude save against its Primary Phase Save DC. With success, he shrugs the entire contagion off and is no longer subject to its effects. With failure, he suffers the listed Primary Damage/Effect and incubates the contagion to its Secondary Onset Time, when he must make a second Fortitude save, this time against the Secondary Phase Save DC. With success, he shrugs the contagion off and is no longer subject to its effects. With failure, he suffers the listed Secondary Phase Damage/Effect and incubates the contagion to its Secondary Onset Time, when he must make a third Fortitude save, this time against the Secondary Phase Save DC. This cycle continues until the character successfully saves against the Secondary Phase DC, dies, or the cycle otherwise naturally ends (per the specific contagion’s description).
Any character who is exposed to a contagion’s antidote automatically recovers.
Each time a character loses 1 or more attribute points to contagion damage, he also suffers an equal amount of stress damage.
When a character is exposed to 2 or more doses of the same contagion, he suffers a –1 penalty with saves made against the contagion for each dose to which he’s exposed beyond the first (maximum penalty –10).
Action dice may not be spent to boost contagion damage.