Plasma Pistol

When rolling To Wound for a model that has the Breaching (X) special rule, or is attacking with a weapon that has the Breaching (X) special rule, for each To Wound roll equal to or higher than the value listed in brackets, the controlling player must resolve these wounds at AP 2 instead of the weapon’s normal AP value. This rule has no effect on models that do not have Wounds, such as models with the Vehicle Unit Type.

For example, a model with the Breaching (5+) special rule that rolls To Wound and rolls a result of ‘5’ or higher, the Wound inflicted gains an AP of ‘2’ regardless of the AP value listed on the weapon’s profile. Note that a weapon that has both the Breaching (X) and the Gets Hot special rules always uses the base AP of the weapon when rolls of ‘1’ To Hit inflict Wounds on the attacking model.

When firing a weapon that Gets Hot. roll To Hit as normal. For each unmodified To Hit roll of 1, the firing model immediately suffers a single Wound with an AP value equal to that of the weapon that was used to attack (Armour Saves, Invulnerable Saves and Feel No Pain rolls can be taken, but not Cover Saves or Shrouded rolls) - this Wound cannot be allocated to any other model in the unit. A Vehicle instead rolls a D6 for each roll of a 1 To Hit. If this roll results in a 1 or 2, the Vehicle suffers a Glancing Hit.

Gets Hot and Weapons that do not Roll To Hit 
Weapons that do not roll To Hit (such as Blast weapons) must roll a D6 for each shot immediately before firing. On a 2+, the shot is resolved as normal. For each roll of a 1, the weapon Gets Hot; that shot is not fired and the firing model immediately suffers a single Wound with an AP value equal to that of the weapon that was used to attack (Armour Saves, Invulnerable Saves and Feel No Pain rolls can be taken, but not Cover Saves or Shrouded rolls) – this Wound cannot be allocated to any other model in the unit. A Vehicle instead rolls a D6 for each roll of a 1 to Hit. If this roll results in a 1 or 2, the Vehicle suffers a Glancing Hit.

Gets Hot and Re-rolls
If a model has the ability to re-roll its rolls To Hit (including because of BS 6+ or the Twin-linked special rule), a Wound is only suffered if the To Hit re-roll is a 1; it may also re-roll Gets Hot results of 1 for weapons that do not roll To Hit.