The answer is about double a regular book. Every branch needs to tell a good story and we try to make all our endings interesting and quirky and fulfilling. So first we edit for story.
Usually an author writes the first thread and a little of a second thread and sends it to the author snake pit. The other YSWW authors look at how interesting the first choice is and the potential for different and exciting threads. We might tighten up the start at this stage and identify issues the writer might encounter.
For instance our first history story (Duel at Dawn) might have had an almost entirely male cast. History tends to be all about what men did and often assumes an all male cast. So Kevin Berry had to think about how he would use female characters. He did a great job and now we are thinking about more historical YSWWs.
When most of the YSWW has been written we do knowledge and tools check. The editor has to track everything a character knows about and the skills and tools they have through each thread. For instance in In the Magicians House you acquire a portable hole in one thread. That hole could get you out of danger in other threads – have you got it or not? Check, check, check…
Then there’s the business of endings. Sometimes you just die. But you can still die in an interesting way – or have something unexpected happen. Eileen Mueller was talking to a reader about her book Mystic Portal and the reader told her that her favourite ending was when you get buried with sand but get rescued to work in an hour glass factory. You have to sign an employment agreement that says you will work there until the sand runs through a big sand timer standing a the end of the factory. After you sign you find out it only drops one grain of sand a day. We wrote that ending very late in the process.
Our readers tell us that these quirky endings are what they love about the stories and that they keep them going back to try new paths.
Another interesting ending that was written in edits happens in Between the Stars. In that ending some passengers finish the journey early when they decide to live on a marginal planet. They do this because they are rescuing a sentient plant and that plant is what might help them to survive. At this stage we’d already published Secrets of Glass Mountain and Blair Polly had a sequel underway. Glass Mountain is a fascinating world and we suddenly saw a way to connect the two books and gain a rich back story. So when you read Volcano of Fire you’ll find more connections between the books.
If you want to write your own interactive fiction you can check out a book I’ve written about the process. I’ve learned that editing is the best part of writing a book, all you can ever do is make it better and you always know you are nearly done.