So I realized I have spent a lot of time fleshing out a world, and have a story planned for it. But it has no sequel opportunity, and I just don't want to abandon the world. So let's assume I get my one story published(just pretend please!), is it possible to work on publishing another story that is in the same world but otherwise unrelated. Even if the first is of no success?
I believe it is possible to write a sequel to a book, even though it does not seem to have lose endings to the first one. You can use the antagonist as the protagonist and write from the antagonist's prospective instead of the protagonist. Another way you can do it is by having the antagonist to try to win the goal after the protagonist has already defeated his/her opponent.
Tamora Pierce: Tortal: The Beka Cooper Series, Song of the Lioness, The Immortals, Protector of the Small, Tricksters Duo Relationship: Beka Cooper series is about a character from the Song of the Lioness and Tricksters Duo, George Cooper's ancestor, Song of the Lioness focuses on Alanna who is mentioned (and met breifly) in The Immortals, Protector of the Small and Tricksters Duo. Protector of the Small centers around Kel, and mentions and breifly meets characters from the other books (and technically speaking the Tricksters Duo takes place across the sea from Tortal). I mean technically you can read each series alone because when you meet the characters from the other serieses enough back story is provided. So yeah, it can be unrelated books for the world, but if they meet characters from the other book, just give enough backstory that you don't have to read the first book (but at the same time make them interested in the first book.)
You can use your fictitious world for EVERY book you write and not link them in any way at all. YOU created the place. It is YOURS to use however you see fit.
Still, don't get so locked in to your one setting to the extent that you won't create an entirely new one if a story requires it. Particularly if you are writing speculative fiction, the setting you create is often intimately tied to the story, so you should be prepared to create a whole new world, or even universe, to best frame your story.
Yes, it is very possible. I am thinking of doing the same thing. I have spent a lot of time on developing my background universe (and I still do), and I see many possibilities there. The next book you write can for example take place in another time period than the first book, or in the same time period, if you like. Just came to think of this: The hobbit, LOTR, Silmarillion. I think this way of writing (using the same universe/background world, yet jumping between time periods) works perfectly for fantasy or scifi. I can't really think of any authors of other genres who have done that though. But Cogito is right: you must not lock yourself so much to your background world that you won't create a new one. Why not have many background worlds? If you manage to, good luck to you. I can only say I have one background world that is developed, but if it felt right for a story's setting, I wouldn't hesitate to create another. Maybe I would even have two or three background worlds interact with each other.
As long as you don't make annoying references, it should be good. Like, if the first story has something to do with a war, and then in the second story, characters pass an ancient battlefield and one of them starts regaling the others with details of the war? Yeah. Don't do it.
Actually I would say you should make references to other works set in the same setting. Sure don't go into massive detail but if you have a war in one story it's logical that people in the next are going to know about it. Else it will just feel detached. Besides people like little nods like this so long as they don't get in the way. Like Frodo and co. going past Bilbo's Trolls.
I almost feel that I won't openly connect them, I don't want them to be held back if the other earlier ones are much worse(by comparison).