Veterans of the Long War

Veterans of centuries or millennia, the Long War's
most embittered warriors have learnt how best
to focus their need for vengeance.
Use this Stratagem in your Shooting phase or
the Fight phase, when a Traitoris Astartes Infantry
or Traitoris Astartes Biker unit from your army
is selected to shoot or fight. Until the end of that
phase, each time a model in that unit mackes an
attack, add 1 to that attack's wound roll.