Sons of Guilliman

Use this Stratagem when an ULTRAMARINES INFANTRY or ULTRAMARINES BIKER unit
from your army is chosen to shoot with in your Shooting phase or fight with in the Fight phase.
If that unit has the Troops Battlefield Role, until
the end of that phase, when resolving an attack
made by that unit, you can re-roll a hit roll. Otherwise, until the end of that phase, when
resolving an attack made by that unit, you can
re-roll a hit roll of 1.