Board Thread:Clean up Concerns/@comment-34097347-20160924191552/@comment-366087-20161209202158

I've always encountered "Immortal" as having 2 tiers.
 * 1) Cannot be harmed or killed by mortals
 * 2) Will not die of "natural" causes, or at least causes natural to them. Mortals can hurt or kill them with effort and usually in limited ways ("the only way to kill x is by doing y") or by use of an artifact from their kind/realm. Preternatural creatures such as vampires are of this tier, and as mentioned, Highlander-type human/mortals.

I stipulate "by mortals" as typically fictional immortals of the same kind are depicted as able to kill each other.