So, for instance, in most of Dark Tower 1, you have "The Gunslinger" and "The Man in Black." I do similar things in my novel, but I'm not sure at what risk I do it. I am doing it quite a bit, because I think it adds to the mystery of the character, and I can reveal who exactly they are at the precise moment, but at some point, I'm sure having "The Man," "The White Spirit," "The Wanderer," "The Cloaked Boy," "The Mastermind," is just overkill (no, I'm not using all of those in my book, just an example). Thoughts and comments?
Brilliant metaphor from Cogito. There are many ways to do this. You can even a single character using several different descriptions AND several different proper names. You could make it into a thing that everytime you mention a certain character you always use a new chacacteristic to refer to him/her with. Using this for more than one or maybe two characters in one book is probably a bad idea, though. It also depends greatly on what kind of person the narrator is and how much is known about the chacter in question etc. You should also think about why you feel this urge to use these descriptors. If it's really just because you want to show off your language skeelz it's probably a terrible idea. If it's for "thematic", in lack of a better term, reasons, though, you might be all good. Try to put yourself in the mind of the readers and consider 1. what they will understand and 2. what they will enjoy. Sometimes, probably most times, it's just as poignant just to use their names and get on with the story. And that last part's important as the longer time you spend describing one character the audience will more and more suncounsciously think he or she will become important either right away or further down the road. Be careful about putting readers off like that.
Christopher Nolan's debut film, Following, has fifteen characters listed in the credits. Only one of them has a name (simply "Cobb"), and it's not even his real name. Other main characters include "The Young Man" (the narrator), "The Bald Guy," and "The Blonde." But the film is so well-done that it never becomes confusing, it never gets on your nerves, you don't even realize the lack of names until you see the credits at the end. Of course there are movies that try to do that and fail miserably - this worked because Christopher Nolan is an outstanding director. With the novel I'm working on right now, only three of the eight or nine characters are ever given names, and the ones who do have names either have a first name or a last, not both. And because of the unreliability of the narrator, these probably aren't even their real names to begin with. Yet I haven't had anyone tell me that it's hard to follow the cast of characters, or that it gets annoying. It's all about how you write it.
The answer, as so often, is: it depends. I personally don't like books where there are too many characters mentioned through their description alone. Saying that I will immediately contradict myself, because I quite like the Game of Thrones where a lot of characters are really only mentioned through their description. So I suppose it really depends on how you do it and how integral those characters are to the plot. Personally I would like to have the protagonists of stories given a name to identify them - and other characters could quite easily just be known by what they do, look like or other characteristics.
You'd better be very sure your intended audience will follow. The more characters you have, the harder it is to keep track of the alternate descriptions and references. Even using a full name one place, the first name another, and the last name somewhere else can be confusing, more so if you also refer to them by description in other places. I'm reminded of a piece by J.K. Galbraith on economics where in one paragraph he used something like "Jefferson thought", "the view from Monticello," and "the Virginian did". I guess he was trying to avoid repeats, but if even if you are enough of a student of history to recognize these references, it still gets in the way of making the point.
Hi, I don't know as the others have said, whether there's any true limit. It's more a question of how important the characters are to the story and how many times they appear and reappear throughout it. Also the description needs some specificity. For example if you had a character called 'The Guard' and then he went to work in a prison, suddenly you'd have lots of guards, all of whom could be confused with The Guard. And The Gunslinger might work, until you put him in a wild west down with lots of other gunslingers. There was a film however, Alien Visitor, in which the entire film has only two characters, and neither has names. One is 'The Man' and the other is 'She'. And because there are no other characters and its well done and there's only short bits of narration, it works quite well, and you don't realise that they are nameless until you read the credits. Cheers, Greg.
I think it would also depend on the context of your story. If you have no names for any of your characters, identifying each of them through their role could work out - especially if that role is what defines them: the Cloaked Boy might have some power pertaining to that cloak, I guess. Alternatively, you could have "Jack", who just so happens to also be referred to by the narrator or other characters as "the man". I would agree with psychotick that it's relative to the other characters as well.
What Stephen King does with those characters is gives them descriptors based on how others see them. The Man in Black is referred to as such by Roland because Roland has known him by so many other names; Marten Broadcloak, Walter O'Dim, Randall Flagg. They're all the same guy. But Roland is following a man dressed in black. It's not King himself who is naming him "The Man in Black" per se. I mean, technically he is, but really it's more than a name. It's his identifier. When you look at the people around you, you don't always know their name immediately. When people look at Roland, they don't see The Gunslinger. They just see a gunslinger. I don't think anyone ever actually refers to Roland as "The Gunslinger" with that sort of implied inflection (making it a proper noun and such). I know the Man in Black refers to him as "gunslinger". The title works as "The Gunslinger" because he's the last Gunslinger of the Eld, but it's not really his identifier like The Man in Black is. His identifier is just "gunslinger". So if you're asking how many characters you could name in that way, essentially by some sort of trope, you could do it with all of them. But I think it's important to recognise the difference between a name and an identifier, and when either is applicable.