Damage Mitigation
Damage-reduction externals turn one-shots into survivable hits. Tanks use them for busters; healers use them to save squishy DPS.
Specs that bring damage mitigation
Vengeance Demon Hunter
Darkness
Protection Paladin
Blessing of Dawn
Protection Warrior
Rallying Cry
Restoration Druid
Cenarion Ward
Preservation Evoker
Rewind
Mistweaver Monk
Life Cocoon
Holy Paladin
Aura Mastery
Discipline Priest
Pain Suppression
Holy Priest
Divine Hymn
Restoration Shaman
Earthen Wall Totem
Devourer Demon Hunter
Darkness
Havoc Demon Hunter
Darkness
Retribution Paladin
Blessing of Dawn
Assassination Rogue
Iron Wire
Enhancement Shaman
Earth Shield
Arms Warrior
Rallying Cry
Fury Warrior
Rallying Cry
Augmentation Evoker
Zephyr
Devastation Evoker
Zephyr
Beast Mastery Hunter
Spirit Mend
Shadow Priest
Vampiric Embrace
Elemental Shaman
Ancestral Guidance