Question: If you're writing a book and you have a planned sequel in your head like 7 books and you get the first one published do you tell your publisher that that's your plan? Or how does that work?
Another question. Is it ok to plan a sequel even if you haven't written the first book but you have an idea and know you want a sequel and even know how each of those are going to play out? Is also ok to have ideas for spinoffs and prequels because you already have ideas for them? Or is that just planning way to far ahead? I know the mortal instruments series is the second series in a planner 5 and there's already been a prequel and the next is another sequel that's first book comes out next year. So that's pretty far planning. Right? Isn't it kind of the same or is it different because that author is already signed?Answer:
The key is to sell that first book. If the publisher really likes the first book and is considering making you an offer, they may ask if you have ideas for a sequel. They would have to really, really like the first book to offer you a multi-book deal right away, especially if it is your first novel, but knowing that you have ideas for a sequel can be a little plus.
If they buy the first book and it sells well, they may then
come to you with an offer to buy a sequel or with a multi-book deal to complete the series.
For these reasons, it doesn't hurt to have some ideas for a series. You might even plan out the multi-book story arcs. Write down these ideas in case you are fortunate enough to sell the first book.
Knowing what happens in the prequel offers another advantage in that it may actually help you in writing the first book.
However, actually writing a sequel or prequel for a book that hasn't sold yet may not be advisable. What if the first book never sells? What if publishers decide the concept behind the first book isn't marketable? That might mean the sequels aren't marketable either, and you will have wasted a lot of effort that could have been spent more productively.
Instead of working on a sequel for an unknown quantity, you could spend that effort writing a novel that's completely unrelated, which you could try to sell even if your first book gets completely rejected. In fact, it's good to work on a different project while you are shopping your first manuscript to different agents and publishers.
Psychologically, it feels better not to have all your eggs in one basket--or in one story world. When you get rejections (and most writers get quite a few of these before selling their first book) you can comfort yourself with the knowledge that you are working on another project that's pretty exciting.