It doesn't really matter, it's a dime store, carnival level prophecy that is entirely based on a technicality of word play. I mean, this is a lich, a wraith lord of the dark lord sauron, one of the elder beings of power from the dawn of time. A being that has infused his will into items of power, and used them to enslave the souls of people of power across the realms, chaining them to him for millennia....capable of dark and terrifying powers of divination and corruption.....and the prophecy this wraith king gets, from whoever he gets it from (seriously is that actually established? I mean tolkien was really anal about detailing out ALL that shit from the dawn of time, so it wouldn't surprise me), is able to trick him with an elementary bit of gender word play? I mean, come on.
The fact that this is a common trope of fortunetelling (this is in response to the above posts saying it gets used a lot, as if that's somehow a mark of quality), doesn't make it good, it just makes a commonly used thing, that's still just as dumb.
Macbeth falling for it I can believe, because he's just a mortal dude, who is established as being somewhat arrogant and vain. But I mean, the beings in LOTR are ancient beings of cosmic and terrible power. But apparently they get their divinations from an automated gypsy machine at a carny. It's just dumb.
Respectfully, Happy, I feel that you have a fundamental misunderstanding of the concept at play. Prophecy as a rule has always been built on technicality and wordplay because at the end of the day it's built on a foundation of bullshit. At best, prophecy is a mix of cold reading and educated guesses bolstered by flowery language that encourages creative interpretation. Simply put, the basic presumption of the credulous regarding prophecy is that a correctly interpreted prophecy is always correct,
but understanding and correctly interpreting the prophecy is an uphill battle at the best of times. And really, anyone with even a passing understanding of historical divination shouldn't be surprised by that. Ancient Greek seers and oracles only 'interpreted the signs of the gods' through methods like inspecting the entrails of sacrificed animals. Ancient Romans interpreted the behavior of birds. The ancient Chinese during the Shang dynasty inscribed questions onto bones, heated them until they cracked and then interpreted how the cracks reflected on the questions. Mesopotamians interpreted dreams.
The list goes on and on, but the long and short of it is that, in history, divination and prophecy has never been treated as being so straightforward as just knowing the future. It was a guessing game based around reading greater meaning into semi-random events. Usually it was treated as a matter of asking the gods/spirits for guidance and them responding through indirect means that required interpretation, like causing a specific stick relating to a relevant verse in the I Ching to fall out of a shaken cup. Or making educated guesses on how the metaphorical meaning of the Tower card in the upright position applies to the life of the person that the tarot reading is for. In fiction, authors tend to keep to the "fortune cookie" spirit of its source material in the sense that prophecy is treated as accurate but rarely fully understood until it is too late to affect the events they describe. As a bonus, the resultant "oh shit,
that's what it meant" element that results from it tends to yield a greater narrative payoff than "you
knew this would happen".
But let's review your bone of contention for a minute. Leave us not forget that this is a prophecy - a statement of what is and would be - not a protective charm. Said prophecy was made by Glorfindel, warning Eärnur not to give chase to the Witch-King, for it was not and never would be his destiny to defeat the ringwraith.
Earnur now rode back, but Glorfindel, looking into the gathering dark, said, "Do not pursue him! He will not return to this land. Far off yet is his doom, and not by the hand of man will he fall." These words many remembered; but Earnur was angry, desiring only to be avenged for his disgrace.
The Witch-King obviously learned of this prophecy, and circumstantial evidence suggests that he made the classic mistake of assuming the prophecy had broader scope than it actually did, and meant he was effectively invincible. That said it is perhaps notable that, when Eowen reveals herself, the story does suggest that he immediately grasped the possible ramifications and then chose to fight anyways. In his defense, he
was a very formidable opponent and the battle could easily have gone the other way. Just because she wasn't a man didn't mean that she was innately capable of killing him. The prophecy was that he would not fall by the hand of man, not that he'd lose if he ever fought someone who was not a man. There's quite the difference between those two statements.