towards some thoughts on series

[swan_tower]

I've had discussions with other writers about how there's tons of advice out there on writing novels, but very little on writing series.

File this one under "stuff I know how to do, but don't know how to articulate or explain." But this one will be less polished than the pieces I wrote on the structure of paragraphs, scenes, and chapters, because I'm really thinking out loud as I go here.

Step one, I think, is to take a look at what a series is. A set of interconnected books, okay. But there are ways and ways of connecting things, and they're not all going to operate the same. After chewing on this for a while, I've decided that you can very roughly sort different types of series into a spectrum from discrete to linked (with two semi-outliers that I'll note as we pass them.) So:

The Non-Series

At the absolute discrete end, you've got books whose only connection is that a single author wrote them. Not actually a series; 'nuff said.

The Setting Series

In this type, the connection between the books is that they take place in a single setting, but otherwise they share no connection of character or plot. (They may not even share authors.) I'm having trouble thinking of any pure examples of this; most often this tends to be a superset of other series, e.g. Discworld or Valdemar being settings that contain both stand-alone novels and series within them, or a shared world like the Forgotten Realms. If you can think of an example that is purely stand-alone novels, whether written by the same author or different ones, let me know. (I think it would need at least three books to serve as a good example; two books in the same setting is a series by the most technical definition, but I'd like something stronger.)

The Cast Series

This is the type of series you commonly find in romance, where each book follows a different set of protagonists and a different plot, but characters from one book appear in another. (Romance often sets this up by presenting you with a group in the first book, e.g. a set of siblings, with the implicit promise that you'll get to see each of them get their own story eventually.) These naturally share a setting as well.

*The Reset Button Series

As the asterisk indicates, I think this one's an outlier. It's the Nancy Drew model: each book shares a setting and a core cast with all the others, but in between books the slate gets wiped clean, which means they have less plot continuity than the Cast Series. Nancy will always be eighteen; Ned will never graduate from college. I'm not sure this is very popular anymore, except maybe in children's fiction -- and maybe not even there?

The Episodic Growth Series

Closely akin to the Nancy Drew model, this has a core cast and a new plot with each installment, but there's no reset button. As a result, change and growth do happen over time. You see this a lot in mystery novels and police procedural TV shows, because it's very well-suited to those genres: each installment starts with a crime and ends with the crime being solved, while in the background there might might be some ongoing character-based subplot about the detective's marriage falling apart or whatever.

The Episodic Arc Series

This one is a hybrid between the previous and the subsequent types. It has self-contained episodic plots, especially early on, but there's also a longer-term metaplot that those episodes may be helping to set up, and the episodic structure tends to fall away toward the end. Examples include Harry Potter and each season of Buffy the Vampire Slayer (and yes, I realize the creators of both those works are not exactly looking great right now, but they're well-known illustrations of the model). Many trilogies feel at least a bit like this, because it's sensible from a business standpoint to write a more or less stand-alone novel that can serve as the foundation for the later two installments.

*The Perpetual Motion Series

Our other outlier, which I think I've only seen in soap operas on TV. Here there can be many arcs going at once, such that while an individual plot may end, the series as a whole doesn't (until it gets canceled). This would be an extraordinarily hard trick to pull off in traditional novel publishing, I suspect, though it could work in indie.

The Metaplot Series

Here there's no real attempt to wrap up a self-contained plot in any particular installment. From the start, you know you're getting a long-term story, and unlike that trilogy approach I described above, the first volume doesn't feel like it could stand on its own. A Song of Ice and Fire is a prominent example of this, along with TV shows like Lost.

The Single Book

And to cap off the other end, we have our other form of non-series: a single novel that just happens to have been published in multiple volumes, i.e. The Lord of the Rings. The difference between this and the Metaplot Series is that in theory the author of the latter type gives each book its own satisfying structure, even if that structure doesn't end in resolution; the author of the Single Book non-series just whacks it apart at the necessary intervals.

I think that covers the whole gamut. Obviously some things are going to straddle the divisions, because no system of categorization is ever perfect; the goal here is to distinguish what shifts of interconnection happen along the way, rather than to make clean boxes that absolutely everything will fit neatly into. And series can change over the course of their lifetime, e.g. what the author intended to be Episodic Growth sprouts an arc plot along the way. I'll chew more on those bits of the concept later. But for right now, I think this is a decent framework? Is there anything significant I'm missing?

(originally posted at Swan Tower: https://is.gd/KmOFjZ)

Comments

[green_knight]

For a while (I understand this has changed) Erikson's Malazan Book of the Fallen worked as an example of the Setting Series. I can't think of any other examples right now, either.

Personally, I'd see the Cast Series as separate from the roman-fleuve (nearest term I'd use is Saga), which is how I'd describe Discworld: a set of connected novels, many of which share characters (but the main character of one may be a walk-on part of another), and overall they chronicle world development (if you think of all the technological and ideological changes, DW moves on a lot over the course of the series.)

Re: Perpetual motion: a lot of Pern works like this: the first third is a recap of the previous novel, the last third leads into the next novel, so that of each novel only one third was truly unique. I stopped reading Pern at around that point...

[swan_tower]

For a while (I understand this has changed) Erikson's Malazan Book of the Fallen worked as an example of the Setting Series.

My impression -- formed entirely from what I've heard about it, mind you, as I haven't read it -- is that it was always planned to be more, so it only looked like that when it was still incomplete. But whether I'm right about that or not, I suspect there's a strong tendency for the Setting Series to be an early phase on the way to it becoming the superset of something else, because somewhere along the line the author decides to do more with those characters, or to bring those two stand-alone bits together into a third thing, etc.

Re: Perpetual motion: a lot of Pern works like this: the first third is a recap of the previous novel, the last third leads into the next novel, so that of each novel only one third was truly unique. I stopped reading Pern at around that point...

When did that start? I don't recall the books being much like that, but I also stopped reading around the time they found the AI.

[green_knight]

it was always planned to be more

I read the first when it came out on the understanding it would be a 10-part series, then read the second which was about completely different characters, and briefly picked up the third (different characters again) and never read it because there were *so many* characters I'd lost track.

I suspect there's a strong tendency for the Setting Series to be an early phase on the way to it becoming the superset of something else, because somewhere along the line the author decides to do more with those characters, or to bring those two stand-alone bits together into a third thing

Absolutely. One usually has more story than will fit into a book, and the temptation to write another book about a character/write a prequel or sequel/have them turn up in a cameo is just too great. I guess I should write a post about that, as my current WIP is part of a Saga arc. (I have two reasons to write this: one, I like the world and the people and it's something I can have fun with in times of stress or little brain, and two, I started out with a basically ok but in places pretty fucked-up culture. No single hero will come in and change everything; the change is part of a concerted effort of many people over a long time, so I'm writing about multiple protagonists who each make a contribution.

[Pern] When did that start?
After the AI thing. I can't recall how long it went on, I remember Dolphins being the one where I recognised the pattern and lost interest, though Moreta/Nerilka also had overlap IIRC, and I seem to recall that some of Jaxom's story overlapped with another book.

The book where I completely stopped reading Pern was Masterharper because it undoes a lot of earlier story, and I just Could Not with Robinton getting all of the credit. (I never read the books that were published after that. I see there's quite a few.)

[sovay]

After the AI thing.

It blew my mind even in high school that she wrote the series ending in All the Weyrs of Pern (1991) and then just . . . kept going. I accepted the existence of the collection The Chronicles of Pern: First Fall (1993) because it was all prequel. And then we hit The Dolphins of Pern (1994) and I tapped out for good.

Nerilka's Story (1986) is effectively a companion to Moreta: Dragonlady of Pern (1983) in that it covers much of the same material from a different character's perspective, hence the titling. The early novels are packed into the same time frame in a way that actually resembles the cast series model: the protagonists of one book are supporting cast in another, the same events affect different groups of characters, there's a lot of crossover but no exactly duplicated perspectives. Dragonsong (1976) and Dragonsinger (1977) are effectively concurrent with Dragonquest (1970). Dragondrums (1979) happens during The White Dragon (1978). I believe The Renegades of Pern (1989) revisits and is interwoven into this period, but it was written sufficiently later than the rest that it doesn't feel quite like the same phenomenon: McCaffrey was writing the two original trilogies at the same time and it shows in how tightly they're linked. [edit] Wikipedia reports that McCaffrey's preferred reading order had the Harper Hall trilogy spliced in between Dragonquest and The White Dragon.

[swan_tower]

Yeah, memory is suggesting to me that I either never read Dolphins or it was the last one I tried. There was a distinct feeling of "why is this still going???" (Obvious answer: "because there was money in it." I don't know if her reasons were mercenary, though; maybe she was genuinely excited about those later ideas.)

[sovay]

Yeah, memory is suggesting to me that I either never read Dolphins or it was the last one I tried.

It was given to me as a present, so I must at least have tried to read it, but I remember bupkes. I just remember seeing it in bookstores and not even understanding why it had been published.

[swan_tower]

I sort of hope I never wind up in a situation where I keep cranking out books in X series because they're too lucrative to say no to. I mean, that falls under "I should be so lucky" in the categorization of professional problems to have, but . . . it just seems soul-deadening.

[swan_tower]

I read the first when it came out on the understanding it would be a 10-part series, then read the second which was about completely different characters, and briefly picked up the third (different characters again) and never read it because there were *so many* characters I'd lost track.

This is one of the things I've been chewing on as part of this mass of topics: how to handle reader expectation, especially when the structure is unconventional (e.g. three seemingly separate books that are all setting up a connected story later). Marshall Ryan Maresca has been doing this with his Maradaine novels, where he's got multiple trilogies in the same setting -- which was great right up to the point where I finished the trilogy I'd chosen to read and discovered that its actual conclusion was in another castle. I didn't know that was coming, and it threw me for a not-good loop.

re: Pern, I think I stopped at Dolphins, either in the sense of that was the last one I read or I looked at it, said "wtf?," and didn't bother trying.

[alexseanchai]

does Anne McCaffrey's Ship Who series count as a setting series, given that characters from earlier books cameo in later ones?

[swan_tower]

I'd certainly peg that one down near that end of the spectrum, though not all the way at the end (which evidence suggests is a pretty rare position for any series to be in).

[edenfalling]

I cannot speak to this from personal experience, but I hear that Iain M. Banks's Culture books are pretty damn close to a Setting Series, with each being a standalone though there are occasional passing references to other books.

[swan_tower]

Good to know!

[sovay]

If you can think of an example that is purely stand-alone novels, whether written by the same author or different ones, let me know.

Le Guin's Hainish Cycle is as near as dammit. Planets and cultures recur, but individual characters do not except in the short stories "The Shobies' Story" (1990) and "Dancing to Ganam" (1993), which is the only instance I can recall across more than thirty years. If that disqualifies it, fair enough. None of the novels are so linked.

this has a core cast and a new plot with each installment, but there's no reset button. As a result, change and growth do happen over time.

A narrative model I really enjoy when done well and really resent when it gets short-circuited.

Here there can be many arcs going at once, such that while an individual plot may end, the series as a whole doesn't (until it gets canceled).

I haven't read them for myself, but C.J. Cherryh's Foreigner series has always sounded like this model, in that I believe it consists of interlinked trilogies across which larger movements of plot and people's ongoing lives take place; all loose ends are not tied up at the conclusion of each three-book arc. Anyone who actually reads the books should feel free to correct me.

From the start, you know you're getting a long-term story, and unlike that trilogy approach I described above, the first volume doesn't feel like it could stand on its own.

A narrative model I just resent.

[edenfalling]

Yes! Absolutely the Hainish novels.

It's nearly impossible to even set them in a chronological timeline, aside from The Dispossessed (which must be earliest because it involves the invention of the ansible) and then Rocannon's World, Planet of Exile, and City of Illusions happening in that order and being very late because of the telepathy and the Shing. And "Winter's King" does have a clear chronological relationship to The Left Hand of Darkness, though I don't remember off the top of my head which comes first. Other than that? Who knows!

[sovay]

And "Winter's King" does have a clear chronological relationship to The Left Hand of Darkness, though I don't remember off the top of my head which comes first.

"Winter's King" has to take place after The Left Hand of Darkness because Gethen has by then an established relationship with the Ekumen, but since neither story references the other, I have to come to this conclusion from internal evidence.

Other than that? Who knows!

It's true. I think it's one of the reasons Le Guin was ambivalent about calling it a "cycle," since that implied some kind of structure which the shared setting totally does not possess.

[edenfalling]

Yeah, 'cycle' implies FAR more structure than Le Guin bothered with. I vaguely recall her actually writing author's notes to the general effect of, "The Hainish Cycle is a massive tangled ball of yarn; please do not attempt to force continuity onto it; you will only give yourself a headache," for later novels.

*belated lightbulb moment* Oh, and "The Day Before the Revolution" connects to The Dispossessed, in that it's a story about Laia Odo's old age. While she's long dead by the time of The Dispossessed, her existence and her philosophy are very relevant to that book and frequently mentioned within it. But while that's a more clearly signposted link, it's still pretty indirect -- again, neither work directly references the other and both can and do stand alone.

[swan_tower]

While she's long dead by the time of The Dispossessed, her existence and her philosophy are very relevant to that book and frequently mentioned within it.

At which point I'd be happy to call it continuity of culture rather than character anyway. But when I write a more polished version of this for my site, I'm planning to note how much of a fuzzy gradient there is between the Platonic ideal of a Setting Series and series where characters from one story appear in another, in varying degrees up to the romance model I mentioned here.

[swan_tower]

Thanks for the Hainish suggestion -- I've read bits of that, but not enough to have known on my own whether it was a good example.

A narrative model I really enjoy when done well and really resent when it gets short-circuited.

I appreciate that this is the model which most closely resembles real life, but after a while I tend to lose interest because it doesn't feel like it's going anywhere. And depending on what type of story it is, I start wishing for the main characters that they could just stop, that they could lay down their weapons or tools and rest at last, rather than there always being some new problem to trouble them. You start to think after a while that those poor people would be traumatized wrecks from all they've gone through.

A narrative model I just resent.

I'm curious as to why. My instinctive reflex is to look to the surrounding circumstances, i.e. series like the Wheel of Time or A Song of Ice and Fire that just keep endlessly ballooning and the author gets slower and slower to put new installments out; it's massively frustrating to have closure eternally tugged out of reach like that. (And I frankly disagree with the attitude that says readers should basically shut up and be grateful for what the author gives them, though I understand that some of the backlash of that sort was born out of readers behaving like inexcusable assholes toward Martin for his delays.) Or you also run into situations where maybe all the books exist, but that doesn't mean you can get your hands on them. But do you resent that model in its own narrative right, even if all the components of it are done and available to you?

[sovay]

Thanks for the Hainish suggestion -- I've read bits of that, but not enough to have known on my own whether it was a good example.

Generally recommended, especially now that you can get the entire thing from the LOA.

I appreciate that this is the model which most closely resembles real life, but after a while I tend to lose interest because it doesn't feel like it's going anywhere.

I've never had the experience of really attaching to a series of this kind and then finding that it ran so long that I tired of its people or wished other lives for them. I don't like all nineteen of the Campion novels equally, but I like its central characters through to the end. My major grief with Torchwood is that there are slightly less than two seasons of an ensemble cast whose interactions and evolving relationships I really enjoyed in the midst of ridiculous alien weirdness plots. I have one open-ended, episodic series that I never returned to; it's the Dresden Files; I read as much of it as existed and I could lay my hands on while my grandfather was dying; Spiders Georg is an outlier and should not have been counted.

I'm curious as to why.

"Resent" is probably too strong; it just chimed irresistibly with the earlier assessment. I don't enjoy the inherent shapelessness of this model—I have read many first books of planned series which do not function as novels so much as whacked-apart portions of plot—and the absence of structure often makes me mistrust the writer's ability to catch up to their ambition. If it sticks the landing, great. But I'm having a hard time thinking of an open-ended, non-episodic series that's done it, even outside of cases where it's unfair to blame the author because they died. In the interests of fairness, because this is a mode of long-form narrative I don't especially enjoy, I haven't read tons of it.

[swan_tower]

I've never had the experience of really attaching to a series of this kind and then finding that it ran so long that I tired of its people or wished other lives for them.

I wouldn't say I've had it happen to anything where I was passionately attached, but there have definitely been episodic series that palled for me before they ended. More on TV than in books, though; where it happened with books, it was most often with things like Valdemar or Pern where the setting as a whole is more than a single series. I enjoyed early Anita Blake, though, and then it just . . . slid inexorably off a cliff.

"Resent" is probably too strong; it just chimed irresistibly with the earlier assessment. I don't enjoy the inherent shapelessness of this model—I have read many first books of planned series which do not function as novels so much as whacked-apart portions of plot—and the absence of structure often makes me mistrust the writer's ability to catch up to their ambition. If it sticks the landing, great. But I'm having a hard time thinking of an open-ended, non-episodic series that's done it, even outside of cases where it's unfair to blame the author because they died. In the interests of fairness, because this is a mode of long-form narrative I don't especially enjoy, I haven't read tons of it.

And in fairness, I can't presently think of any examples of a successful metaplot-style series that didn't at least have their first installment feel reasonably self-contained. I don't believe it has to be inherently shapeless; just as there can be substructures within a single novel, I think there can be substructures within a multi-book series. But we don't have a large number of models to follow, the way we do with other types, and the most prominent models we do have (e.g. the Wheel of Time and A Song of Ice and Fire) are . . . kind of rolling disasters when it comes to their structure, because the authors visibly made some very bad decisions about how to approach the work. So I'll admit that in its pure form, I can't name any good examples of this off the top of my head. (Though I'm going to ponder and try to find some.)

[sholio]

And in fairness, I can't presently think of any examples of a successful metaplot-style series that didn't at least have their first installment feel reasonably self-contained.

Yeah, I was just trying to think of one too. Even back in the sprawling fantasy epic days, they tended not to be entirely lacking in some ability to stand on their own, if only because it was a lot riskier for a publisher to take a chance on the first book of an open-ended series that might or might not do well if it couldn't be marketed at least somewhat independently.

About the closest I can think of are some shortish series (trilogies/quadrologies) that function as a fairly tightly plotted unit, basically a single book that's 400K long - like Julian May's Pleistocene Exile, say, where the first book (IIRC) very much does not feel like a book that is complete in itself, but the series doesn't wander on for 20 books either.

I think this model does exist in manga, but doesn't really seem to have caught on in Western publishing. And even there, the first few installments are usually at least somewhat standalone until it becomes evident that the series has legs.

[swan_tower]

if only because it was a lot riskier for a publisher to take a chance on the first book of an open-ended series that might or might not do well if it couldn't be marketed at least somewhat independently.

Right -- these days there's definitely a strong push to sell a stand-alone book "with series potential." If you try to do something that's metaplot out of the gate, there's a much bigger risk of leaving your readers hanging if the publisher says, on second thought, nah. I don't know if that was equally true, say, thirty years ago.

About the closest I can think of are some shortish series (trilogies/quadrologies) that function as a fairly tightly plotted unit, basically a single book that's 400K long - like Julian May's Pleistocene Exile, say, where the first book (IIRC) very much does not feel like a book that is complete in itself, but the series doesn't wander on for 20 books either.

That's my suspicion, too -- that if I dredged my brain not for the famously long series, but for trilogies and the like, I'd find some examples where it's more clearly a continuous story (without being a clusterfuck of bad pacing and structure). But trilogies in particular have been stamped so very strongly with what I think of as sonata structure -- which I could have sworn I wrote an essay about already, but my website shows no evidence of such a thing having ever existed -- basically a stand-alone movement in a major key, a complication in a minor key that ends without resolution, and then the recapitulation of the theme, now Bigger! and Better! and in a major key once more -- so you're going to get a lot of the "well done; medals for everybody" endings in the first book.

I think this model does exist in manga, but doesn't really seem to have caught on in Western publishing. And even there, the first few installments are usually at least somewhat standalone until it becomes evident that the series has legs.

Now I'm thinking of Chinese webnovels -- except that my impression of those is that they tend to be published a chapter at a time, without the additional layer of structure imposed by separate volumes. (I could be wrong, though; what I know about those comes secondhand.)

[benbenberi]

I'd classify Cherryh's Foreigner series more as a form of "Metaplot Novel" in this schema. There are only 2 POV characters in the whole series so far, one of them introduced as a young child, and a handful of ongoing storylines that each get some time as the main focus of attention then recede for a while, then come back to the center. The trilogy structure originally tracked these changes of focus pretty closely, but not so much anymore: I wouldn't actually consider them trilogies at all any more, except perhaps for accounting purposes. The story just continues from volume to volume.

[davidgoldfarb]

Lawrence Watt-Evans' Legends of Ethshar is pretty close to a "Setting Series". It's not absolutely pure: some characters who star in one book will guest-star in later books, and there's a noticeable sub-series about the start and end of a particular kind of magic. (Although even in that sub-series, the star of one book won't be the star of the next.)

The first dozen or so of Piers Anthony's Xanth seems like it also qualifies — I limit it to that because I have no idea what he's done with the series since the late '80s.

[swan_tower]

I have as near as makes no difference jettisoned my memories of Xanth, so I couldn't tell you. :-P

[marycatelli]

The danger of the last two was warned about as long ago as Aristotle.

"Again, a beautiful object, whether it be a living organism or any whole composed of parts, must not only have an orderly arrangement of parts, but must also be of a certain magnitude; for beauty depends on magnitude and order. Hence a very small animal organism cannot be beautiful; for the view of it is confused, the object being seen in an almost imperceptible moment of time. Nor, again, can one of vast size be beautiful; for as the eye cannot take it all in at once, the unity and sense of the whole is lost for the spectator; as for instance if there were one a thousand miles long. As, therefore, in the case of animate bodies and organisms a certain magnitude is necessary, and a magnitude which may be easily embraced in one view; so in the plot, a certain length is necessary, and a length which can be easily embraced by the memory. "

[swan_tower]

There are many points upon which I disagree with Aristotle . . .

[edenfalling]

It occurs to me that the Oz books are somewhere between a setting series, a cast series, and a reset button series. There is clearly some continuity -- new characters are introduced, people have and use items they pick up in previous books, people move to Oz -- but it's also a fairy country where people don't really age. And especially once you get into Ruth Plumly Thompson's continuation books, they often move away from Baum's core cast and explore random new corners of Oz and minor background characters from previous books.

[swan_tower]

I'll confess I've never read any of them -- only seen the movie and various other Oz-based media.

[edenfalling]

I'm not sure how I'd react reading any of the Oz books as an adult with no childhood nostalgia, but I've found they hold up fairly well if you enjoy highly episodic plots and a lot of whimsy.

[jreynoldsward]

I have found in writing series (three so far!) that the main story arc really does come to a conclusion at some point, and when you reach that endpoint, it's either time to start a new series in that world or move on.

Interestingly, of my three series, only the fantasy series has a "new series in that world" prospect. The first science fiction series, The Netwalk Sequence, really has a full arc and while I might write about different characters in that world, the most I might do is write a short story or two about those characters. We'll see what happens because I plan to do new covers, fix a few tech issues, and reissue this fall.

So it's somewhat interesting to look at series from this perspective. I can't imagine working on an open-ended or reset series (though suddenly I have a notion about how such could be...entertaining...) but I know other people who couldn't do anything else.

The most recent science fiction series, The Martiniere Legacy, is a mix. The first three books (Inheritance, Ascendant, Realization) are a definite trilogy. The fourth book, The Heritage of Michael Martiniere is a standalone that takes off from the trilogy but does not require reading the trilogy to know what's going on. Broken Angel: The Lost Years of Gabriel Martiniere (out late April/early May) is a prequel to the trilogy but again, does not require reading the trilogy first.

As far as the fantasy series is concerned, I'm getting ready to write another trilogy in that world because while major arcs were concluded at the end of the Goddess's Honor series, there was enough left over to kick off another trilogy.

It's interesting thinking about series from the writer's perspective. While I can't imagine writing an open-ended series or a reset series (though I just got an interesting notion about how to do that and have some fun with it) I know that there are other writers who do like writing those series. Mileage varies.

[swan_tower]

Yeah, a truly open-ended, episodic series holds no interest for me as a writer. I want to feel like I'm building toward something larger, even as I try to make each component interesting and satisfying in its own right.

[carbonel]

Patricia Wrede's Lyra novels count as a Setting series, I think. There are five of them, all unconnected and distributed in time, though there are occasional references to events in others of the books.

https://en.wikipedia.org/wiki/Patricia_Wrede#Lyra

[mindstalk]

The Chalion novels are close to a Setting series. 3 novels, 3rd one is centuries before the other 2. 2nd promotes a minor character from the 1st into the main character, and others get mentioned, but it's still a big jump; none of the 1st mains appear on page.

But the same world has the Penric series of novellas, Episodic Growth I guess?

I second the Culture series, it's pretty Setting. Diziet Sma pops up in a couple of books, that's about it.

Some shared world settings might try for Setting series: Merovin Nights, maybe Thieves' World, Man-Kzin Wars? Wild Cards does share characters among stories, I think.

Oh! People mentioned Foreigner but overlooked Alliance/Union. That's pretty close to Setting. Signy Mallory shows up in 2-3 books though she's only POV in 1, but there are a lot of cast-distinct books.

[swan_tower]

The shared worlds I'm familiar with tend to contain trilogies and the like within them, but it's not a requirement for the approach, certainly.

[tortoise]

Claire North's most recent book (The Pursuit of William Abbey) has a paragraph in which someone lists a bunch of rumors of weird events, and they're essentially North's past bibliography. I guess this straddles the boundary between setting series and non-series.

A couple other variants of cast series are:

-One secondary character who shows up in everything. I feel like this may be a kids-book thing; the two examples I can think of are the Chrestomanci series (originally, before it started developing more continuity) and Bruce Coville's magic shop books.
-The thing Tana French did with the Dublin Murder Squad books: each protagonist after the first book was a secondary character in a previous book, so by the time you get to the last one I think they're three or four degrees of separation away from the original protagonist. I can't think of any other examples of this, but I wish I could!

[swan_tower]

That last is sort of a daisy-chain approach! No examples of it come to mind for me, but that's interesting.

[lokifan]

One secondary character who shows up in everything. I feel like this may be a kids-book thing; the two examples I can think of are the Chrestomanci series (originally, before it started developing more continuity) and Bruce Coville's magic shop books.

I was about to mention this! DWJ seems to have done it a lot - Howl and a couple of paired books do this.

[mindstalk]

Steven Brust slips Devera into all his books, across genres and universes, though she doesn't always get named or speak.

I think Death appears in all the adult Discworld books.