Poisons and toxins are substances that attack the body's natural systems causing harm. There are endless varieties of poisonous substances within the Calixis Sector; from natural venoms to toxic pollutants that can kill as quickly and surely as any blade. In game terms, poisons and toxins are divided into three factors; their speed, their strength and their effect.
The following has been copied from the official Dark Heresy GM Screen.
Speed defines how quickly the poison will enter the victim's system.
Instant: the poisons effects occur as soon as the victim is exposed; venoms and poisoned-attacks operate at this speed unless noted.
Swift: the effects of the poison will occur 1d5 hours after exposure; includes subtle poisons such as those favoured by assassins to taint food.
Slow: the effects of the poison will occur 1d5 days after exposure; includes environmental poisons and taints.
In order for the poison to take effect, the victim must fail a Toughness Test. The strength of the poison is the modifier to this Test. Some relatively weak poisons will provide a bonus rather than a penalty to the Test. Note that "-" denotes that the poison has no Toughness Test modifier.
Poisons are grouped into four types of effect; however numerous "more unique" effects are also possible.
Lethal: these poisons cause harm by directly attacking the body's functions; damaging the nervous system, causing cardiac arrest, etc. The victim suffers 1d10 temporary Toughness Damage plus a further 1d10 per degree of failure. if reduced to "0" Toughness they will die unless they receive immediate medical help (or burn a Fate Point to avoid such a demise). Additionally, if more than half the victim's Toughness is lost they will also become comatose for 1d5 hours.
Paralytic: these poisons paralyse the musculature, rendering the victim immobile or helpless without rendering them unconscious. The victim suffers 1d10 temporary Strength damage plus a further 1d10 per degree of failure. If reduced to "0" Strength they are completely paralysed and unable to act. This paralysis and Strength Damage wears off in 2d5 minus the victim's Toughness Bonus in hours.
Sedative: these poisons incapacitate and render the victim unconscious. Those failing the Toughness Test are Stunned for 1d10 minutes, however, if the Test is failed by 3 or more degrees the victim falls unconscious for 1d5 hours.
Necrotic: these poisons cause localised damage to the body by corroding or otherwise damaging tissue and cells. Many acids and industrial pollutants cause damage this way, as do many natural types of venom intended to liquefy and digest flesh. Victims failing a Toughness Test against this form of poison suffer a variable amount of extra Damage to their Wounds (usually 1d10) with no reduction for armour or Toughness Bonus.