Rending (X) "With a Weapon that has the Rending (X) Special Rule, there is a chance that a Hit Test may result in an automatic wound."
When any Hit Test is made for an attack with the Rending (X) Special Rule, if the result of the Dice roll, before any modifiers are applied, is equal to or greater than the value of X attached to this variant of the Rending (X) Special Rule, then if a Hit is inflicted by that Hit Test, that Hit becomes a 'Rending Hit'.
When required to make a Wound Test for a Rending Hit, no Dice are rolled and the Wound Test succeeds automatically regardless of the Weapon's Strength or the Target's Toughness Characteristic. The Wound Test is treated as if the result had been '6' for the purposes of any Rules that would be triggered on certain results of a Wound Test. Wounds caused by a Rending Hit use the AP and Damage Characteristic of the Weapon used to make the attack and retain any Special Rules that Weapon had.
If the Target Unit for an attack made with a Weapon that has this Special Rule includes any Models with the Vehicle Type, then this Special Rule has no effect.
Poisoned (X) "A Weapon with the Poisoned (X) Special Rule has a chance to cause a wound regardless of the target's Toughness Characteristic."
When making Wound Tests for Hits that have the Poisoned (X) Special Rule, if the result of any Dice rolled is equal to or greater than the value of X attached to the specific variant of this Special Rule then a wound is caused automatically, regardless of the Toughness Characteristic used to determine the Target Number. A Hit that has this Special Rule may still inflict a wound by passing a Wound Test as normal, instead of using this Special Rule, but never inflicts more than 1 wound if it would both pass the Wound Test and trigger the Poisoned (X) Special Rule. Wounds caused using the Poisoned (X) Special Rule retain the AP and Damage Characteristics of the Weapon and Saving Throws and Damage Mitigation Tests may be made to discard them as normal. The Poisoned (X) Special Rule has no effect on Models that have the Vehicle Type, and limited effect on Models with the Automata or Walker Types (See the Rules for Walkers and Automata in the Warhammer: The Horus Heresy - Age of Darkness Rulebook).