First, I should define some terms. What is the Initiating Incident? It’s that moment when your character is jarred out of their rut, their life changes and story truly begins. In screenwriting terms, this is when the character passes from the Old World into the New World of the story.
Some authors advocate always using an establishing shot of the Old World, some always starting with the Initiating Incident. Both can work. Both have advantages and disadvantages.
A beginning that starts with an Initiating incident is often more action-packed and interesting. They raise immediate questions in the reader’s mind. What is going to happen next? Will the hero prevail? The drawback is that the reader doesn’t care about the characters yet. Mindless action alone doesn’t engage.
However, it is possible to write an action-packed beginning that makes your reader begin to care about your main character. Karen Robards does it all the time with her romantic suspense books. Goblin Emperor by Katherine Addison starts with an initiating incident (the arrival of an airship with the new that Maia’s father and older siblings have died and he is now the emperor) and yet also immediately engages reader sympathy (Maia has been in cold lonely exile for his entire life.)
The advantage of an establishing shot beginning is that you have an opportunity to show what the character is like before their life is upended and thus can show how devastating or necessary or frightening that change is to them. The disadvantage is that with many characters their Old World simply isn’t very interesting. (This depends on the character. James Bond movies always start with an action-packed establishing shot of Bond doing spy stuff. His normal world is interesting.)
So how do you know when to use which? It depends on the particular demands of your story.
For example, I chose not to do an establishing shot for my novel Through Fire & Sea. I would have had to start off showing Leah scrubbing floors and I deemed it too boring.
In another novel, Gate to Kandrith, the Initiating incident is when Sara finds out she’s being sent to Kandrith as an ambassador. This is how my first draft started, bang, dive right in. But the published version starts two chapters earlier: while rewriting I discovered that I needed time to introduce the decadent, corrupt world of the Republic and develop some of the characters that lived there because they were important to the book’s ending. This was absolutely the best way to start this story. Otherwise when the villain showed up at the end, the reader would have been “Who IS this guy?”
Different mediums may require different beginnings. Movies are much more likely to use the Old World, New World method. People decide to go see a movie based on the trailer. They’ve paid for their ticket. They’re not likely to get up and leave the theater if the first five minutes are a little slow. Books are a different ballgame. People will put down a book if the first two pages don’t grab them.
Think about the difference between the opening for The Martian by Andy Weir and the movie. Both were smash hits, but I honestly believe the book wouldn’t have grabbed as many readers if it had started in the same place that the movie did: before the accident leaving the hero stranded.
Of course, Initiating incident and Establishing shot aren’t the only options. There are a couple of hybridizations.
The Hunger Games starts off with a tease. We are told that it is the day of the Reaping but not what that means until after ten pages of Katniss’s Old World. The drawback to a tease is that the reader won’t wait forever for the payoff.
Another solution is to have a bridging conflict, so that something of interest is happening to your character while you establish their Old World. This is what I ultimately used in Gate to Kandrith, showing Sarah at a very tense political dinner.
Remember, the first beginning you write isn’t chiselled in stone. I usually rewrite my beginning more times than the rest of the novel. Don’t be afraid to take several stabs at it until you hit one that accomplishes what you want. Good luck!