Every good novel needs conflict, something that prevents its hero from achieving his or her aim.
Superman wants a safe world, Lex Luthor wants to take it over and doesn’t care who he kills to do it. Girl wants boy, but they are prevented by their fathers’ ongoing feud.
The hero must have a goal. It’s not necessary for the plot to slavishly follow the hero’s journey as laid out in Christopher Vogler’s book on writing, entitled The Writer’s Journey (though, by golly, this works), but the hero must want something — even if what s/he wants is for something not to happen, e.g. the comet hitting the planet and ending the world as we know it.
By the way, what the hero wants usually defines the genre. For example, boy wants a particular girl (Romance). Sherlock Homes wants to find out who dunnit. (Crime/Mystery).
Real conflict is where the hero encounters circumstances — or people — who prevent him from saving the world, solving the crime, getting the girl. It is NOT the hero having an ongoing personality conflict with another character so that the novel is filled with lots of petty arguments between these two.
This is not what the mavens mean when they talk about conflict. It does not advance the plot, and becomes mighty irritating after a while.
Beware also of writing scenes that deliver information, rather than containing conflict and moving the plot along. I see this one a lot: two people sit down at a table, and over cups of tea talk about something the writer wants us to know. Maybe it’s the hero’s childhood, why he is like he is today. If all your scene does is convey information, watch out. Every time you do this, the momentum of your plot slows to a crawl.
There are usually better ways to convey information rather than through dialogue. While I’m not a big fan of flashbacks because they interrupt the forward motion of a story, a well written flashback is a more interesting way to present back story information than via dialogue. But of course, anyone who’s good with dialogue finds it much easier to write a conversation with that information in it, rather than actually writing the scene these people in the kitchen are talking about— which could’ve been a real scene with real conflict.
Think about it.
“Oh dear, Mavis, he must’ve been soo scared, him being only five an’ all at the time” is not nearly as exciting as showing us the scene in which our five-year-old hero is scared.
There’s an even better way to tell the reader something and that’s to tell it. Yes, I know: tell has become a dirty word these days. But if you do it succinctly, in one or two sentences, you’ll get away with it: Jimmy was traumatised at the age of five by his mother’s lingering illness and death. There, it’s done. Without interrupting the forward flow of the novel and taking an entire scene to convey.