Some captains and warchiefs in Middle-earth: Shadow of Mordor are invulnerable to range but can be damaged by fire. The question is whether fire arrows will do damage to warchiefs and captains that are invulnerable to range bu vulnerable to fire damage.
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Do Fire Arrows Damage Warchiefs Invulnerable to Ranged?
The answer is that the arrow itself does no damage but the captains and warchiefs will still get set on fire which does dot damage (damage over time). So captains and warchiefs that are invulnerable to ranged can be damaged by fire arrows.