Blood Feud All units with the Veterans of the Long War special rule re-roll failed To Hit rolls in every round of close combat when attacking Space Wolves units. However, all Space Wolves units have the Hatred (Thousand Sons) special rule.
Fear At the start of each Fight sub-phase, a unit in base contact with one or more enemy models that cause Fear must take a Leadership test (called a Fear test) before any blows are struck. If the test is passed, all is well and there is no effect. If the test is failed, the unit succumbs to fear - all models in the unit have their Weapon Skill reduced to 1 for the remainder of that Fight sub-phase. Note that a model that causes Fear is not itself immune to Fear, and will still need to take a Fear test if it is base contact with any enemy models that cause Fear.
