Intractable This special rule applies to all Dark Angels with the exception of the Deathwing, who are already Stubborn, and members of the Ravenwing. Intractable models that fail a Morale check as a result of taking 25% casualties in the enemy Shooting phase will not fall back as per the normal Morale rules. Instead, they will not be able to move in their next Movement phase, or assault in their next Assault phase, but may fire as per the normal shooting rules. All other Morale checks are taken in accordance with the rules given in the Warhammer 40,000 rulebook.