Mainly this applies to long series, or multiple series with the same themes. I’ve written both, and noticed some of the same problems in each. Some advice to keep the characters changing, in the service of change rather than static formulas.

(Of course, static formulas may be fun depending on the genre. Mysteries and romances often thrive on them. But if it’s not obvious by now, I think fantasy can be more than that. Yes, I am biased. Fantasy kicks much ass).

1) Make sure to change your lead character’s personality over time.

This is one reason I find it hard to read hard-boiled detective series; the detective always seems to have the same baggages, the same methods of doing things, the same lines. They evolve beyond character quirks into strict outlines the character must fit- or rather, they don’t evolve at all, which is the problem. The only one of these series I ever managed to enjoy was Raymond Chandler’s Philip Marlowe series, probably because of Chandler’s language.

This static nature can kill a fantasy series, since very few of them have the structure of repeated adventures that a detective series does (another of Chandler’s saving graces). Most fantasies tell an advancing story, about saving the world or completing a quest or fighting a war or building a society- or should. An unchanging main character is a grand way to make it seem as if the story isn’t advancing at all.

Give your lead character problems that alter him permanently. Make him suffer. Make him grow (or lose) in magic. Shake his whole world up in one novel and show him dealing with that in the next. Above all, don’t let healing processes take him right back to the person he was before. I detest the scene- and it comes in most fantasy novels- where a character wakes from a coma or returns from a mission or comes out of depression, and “smiled the same way he always did.” He wouldn’t smile the same way he always did. It might not be weaker, if the experience strengthened him, but it should be changed.

I think the need for change is greater, not less, when dealing with immortal characters and long stretches of time in a book or between one book and another. Otherwise, your immortal characters become lifeless caricatures, a la most fantasy elves, and the years mean literally nothing. Only if you’re really going for this should you leave immortal characters the same, and that makes it all the harder for readers to relate to them. Most authors don’t hesitate to give immortal characters physical advantages. Why strip all emotional complexity from them as a punishment?

2) Keep count of the years.

If you have a ten-year-old character at the beginning of the novel, and by the end seven years have passed, the character should be seventeen. I know, this is probably the most obvious thing you ever heard in your life, but it gets ignored in a lot of fantasy series. To an extent the blame can be laid at the feet of series in other genres, such as the endless high school series like Sweet Valley Twins where the characters never age, but a lot of it is people not wanting to alter their characters again. The seventeen-year-old acts as calm and submissive, or as defiant and nasty, as the ten-year-old, with no change at all.

A lot of people do try to make some adjustment for teenagers, but even there, change happens up to a certain point and then stops. The hero who lost his “true love” at sixteen will still be brooding about this ten years later, when he’s twenty-six, with no sign that he’ll ever stop, unless the author just as mechanically strips him of grief and brings in a new “true love.” Time doesn’t appear to touch the character’s personality at all, never mind his wounds.

A comparison with yourself can be valuable here. Imagine what you were like ten years ago. What did you care about? Now ask yourself how many of those same things you still care about.

Most people lament the passing of favorite cartoons, fads, foods, toys, concerns, and so on with, “Oh, yeah! I remember that!” Why not adapt that to the fantasy world? Why does the hero always recognize the heroine at once when she comes walking up to his door ten years later? Why not have him squint his eyes, stutter around her, and perhaps even have forgotten that incident she was referring to?

3) Incorporate mortality as well as eternity.

Often, deaths in fantasy are excused with some tale of an afterlife, or the idea that “Well, they died in the service of a higher purpose, so it’s all to the good.” This diminishes grief, and, I think, is one of the reasons that fantasy characters can seem to go unmarked (except in the most superficial ways, such as the frozen PTSD-like reaction I mentioned earlier) by death and loss. Mortality is tucked away. Loss dies a death. Characters are deposited in front of elves to watch them sing, say, “Oh, how sad,” and then hustled away to a new pretty thing, without ever thinking of the elves again.

I don’t usually think much of Tolkien as a characterizer, but he manages to evoke sadness with a master’s hand. The Fellowship sees beautiful things (Lothlórien, for example) that are dying, and then the Elves leave Middle-earth, and the appendices of the books conclude with the dying or passage over the sea of the major characters. It’s one of the things that makes Middle-earth seem like a complete world, that it can have an end.

Mortality can change your characters. If your sheltered princess, who’s never been in any danger before, comes near an assassin’s knife, what is she going to think? It should affect her far more profoundly than a little faint and screaming fit, and it shouldn’t be completely soothed away by one of the other characters saying he’ll protect her.

4) Don’t contain change just because the story is self-contained.

Don’t end a story or series or book with the assumption that the character isn’t going to change any more. I roll my eyes when the characters appear to be perfectly in love, when the royal pair is perfect for the throne, when everyone predicts perfect children and no more threats for them. The story ends there, and with it, the characters cease to live. There should be at least doubt for them off the page.

Many authors know the sensation of characters running away from them in the story. The end is your chance to let them run away from you forever. Let the reader wonder what is going to happen. Implant seeds of arguments, perhaps not ones that would tear the couple apart but ones that would happen. Don’t try to imagine their family life; after all, especially if they come from abusive or tragic backgrounds, there’s no guarantee they’ll be perfect parents. Don’t make it clear what kind of life is waiting for them. It could be anything. This is much better than one of those stupid epilogues taking place a few years later that makes it clear the characters have no enemies and the most beautiful children and the most wonderful lives imaginable.

It’s hard to achieve a balance of this and satisfying your readers, of course, but my favorite authors all manage it. Their characters are people, not models the authors are positioning on their stage for their own amusement.

5) Challenge yourself.

This is the best way of avoiding repeating themes. Written two books or two series about saving the world? Do something different next time. Force yourself to write from the perspective of a character who’s the complete opposite of your previous main character. Tackle a different fantasy subgenre. Do research in a different direction. If you wrote an all-human society the first time, do this one from within a non-human society.

Sometimes all that’s needed is a change of setting. I’ve completely ignored Terry Brooks’s Shannara series for a while, because he seems to repeat the same themes and pattern of saving the world in all of them. (His concentration on a few families doesn’t help this). But he wrote an urban fantasy trilogy that I actually enjoyed (Running with the Demon, Knight of the Word, Angel Fire East), because, even though it was also about saving the world, he dealt with a much darker canvas, two main characters in unpredictable patterns, and evil forces not incarnated in mystical objects, the way they tend to be in Shannara.

The comforts of writing a familiar world are, of course, comforts. That can’t be overstated. I know that I’m in danger of being trapped in minutiae in the first world I created; I’m no longer in need of establishing huge political and historical structures, so I write stories that delve into things happening around the edges instead. But these end up connecting back to other stories I’ve already written. I’ve gotten suspicious of myself there. In new worlds, I’m forced to cope with different races and geography and circumstances, and not rely on what I’ve already established.

6) Know when to let go.

I’ve lost all respect for authors like Jordan and Goodkind and R. A. Salvatore, Laurell K. Hamilton and Mercedes Lackey. It went first for their writing ability, and now I get impatient with the way they’re stretching their series. Either they’ve lost all control of their casts of characters, or they’re milking them for money, or both.

It’s probably possible to stretch any story, and even easier with fantasy than with most of them, since they often have a whole new world to play in, large casts of characters to show off, and magical systems to explore. But at some point, you have to leave. Your characters have their own lives to lead (see point 4). If you’re writing a biographical fantasy that’s with them from birth to death, at some point they still have to die. If you’re writing about their children (must you?) those children will pass beyond you, too, especially if you’re faithfully paying attention to point 2 and aging them. Family-centered or dynasty-centered fantasies can be fun, but only if the characters have their own personalities and aren’t just repeats of their ancestors. Too many of them are. At that point, it’s time to wave them on into their own sunrise and go on into your own.

This is a reason that it’s a good idea to develop a sense of the length of a series. If you know that a trilogy will contain it best, don’t start changing your mind about that just to spend more time with the characters, no matter how much you love them. And don’t write another trilogy in continuation if you don’t have something truly new to say.

There’s a special situation that applies when an author isn’t stretching a series for money, love of the world, or love of a family, but because of falling in love with a character. This is yet another reason out of the grand panoply of them to avoid falling in love with your character. Writing book after book about the same character because they’re who you love turns comfortable and boring and eventually unreadable. Most series disintegrate in quality as they lengthen. The only exception I can think of is Terry Pratchett’s Discworld series, and he pays attention to time and past experiences, doesn’t spend every book on the same group of characters, and has changed his writing style from one filled mostly with humor to one filled mostly with satire that cracks down all the harder for being thoughtful and not a joke-a-minute. (And even then, there are people who don’t like his newer books).

Know when to say good-bye, unhood the falcon, and let it fly.

It’s a shame, really, how many stories are spoiled by the characters always being the same over book after book.