Technical Topic -- Starting With a Dream

Elsewhere, folks are discussing beginning the story with a dream sequence.

I have lots of stuff to say. 
Most of which I have already gifted to the world but am perfectly happy to say again.

So I go something like this:

Dear Dreamer,


When we approach a new story we ache to start with what happened to everybody in fifth grade and the history of the Seven Kingdoms and acting-out-stuff-we-could-tell-in-200-words. We are convinced the reader needs to know all this infodump and backstory to understand what's going on.

But this -- generally three chapters of -- backstory and infodump
doesn't belong in Chapter One.
Chapter One has lots of other stuff it needs to do,
and backstory gets in the way of doing that vital stuff.

A dream, even a recurrent dream that is important to the plot, sounds very much like backstory.

If you need the info contained in the dream, drop it in Chapter Eight:


Maurice looked up as she came in. "You look awful," he said.

"Another of those dreams."
 
He pulled over a new plate and put half his English muffin on it. Not the part he'd bitten into. The other half. "Tell me about it."
 
"I don't want to--"
 
"Tell me."
 
She dropped into the chair, propped her forehead in her hands and spoke, not looking at him. Not looking up. "It was ... 1943, I think. Or '44. I was a nurse, somewhere tropical. The South Pacific. They were bringing in sailors all mangled to bits. Some ship had been hit."
 
"And you were working on them. A bad enough dream." Maurice put milk in a cup of coffee. No sugar.
 
"I wasn't working. I was in ... a big browny-greeny tent. Hot. Sweaty inside. I was in my quarters in the tent, looking in a mirror. That was the worst, worse than what happened next. I looked in the mirror and it wasn't me."
 
"Like the other dreams."
 
"Like all the rest. I had a gun. I shot myself, looking in the mirror, seeing myself do it."
 
"Drink your coffee." Maurice set it down at her elbow.



That's 200 words. It conveys the information. It doesn't tangle the feet of Chapter One when Chapter One is busy doing other things.
It doesn't pull the reader out of the ongoing story to tell a little barely connected pocket story.
(If you absolutely must act out the info in the dream, this can become a flashback.)

And plopping the dream into the realtime of the story lets the protags immediately relate to the information of the dream.
That protag reaction gives the dream emotional meaning.