I have read that, Settings are centrally important to the novel. They have to be generally motivated, as they are integral to the plot and storyline. Unless you are writing a picaresque it is unwise to have more than three settings.
I have four Settings in my historical fantasy novel.
Many novels have one Setting, where for example the events take place in a city, town or on a boat.
In Wuthering Heights by Emily Bronte, the Settings are Wuthering Heights and Thrushcross Grange, which are four miles apart and separated by the heath which is integral to the plot and storyline.
I think any writer who considered all these rules as they sat down to write would end up with a very formulaic book at the end. I set no boundaries at all and just try to visualise the end as a sprinter might. When I edit I then consider all the rules and how many of them I might be able to make my MS obey!
Incidently, someone told me they know a reader who can tell whether someone has taken the masters in creative writing by their opening chapters. It seems the rules are so strict on the first three that someone who adheres to every single one stands out as the well-studied one. She didn't say the reader discounted them for that reason and I seriously doubt they do, but it does make me think that if book openings are becoming so regimented the obvious differences of self-published kindle works might be appealing to readers simply because they are so different.
Adrian is asking these questions to trigger debate, Louise. Anytime you want to put as much time and effort into our community, feel free.
As usual I have to shamefully admit to excess. My characters are travelling so each chapter is a different location. Although, with Louise's definition in mind, perhaps I can simply enter the setting as the world!
I have to say, though, I mostly chose easy to picture locations so there is very little description in each place.
I agree that three is good, Ciprian. The contrast between two Settings, with the third as a fulcrum.
It is the atmosphere of the Setting that stirs the imagination. The comparisons in society: status, wealth, poverty, and social justice. Dickens makes superb use of his Settings in many of his novels.