Massacre in a dream: what does it mean?
Dreams of mass killing are reported by people who have witnessed such things and by people who have only watched the news, and the two are not the same dream.
How do the four traditions read it?
Each reading below comes from a named tradition and a cited source, so you can see where it came from and decide what fits your dream. The four often disagree, and that is the point: a symbol rarely means one fixed thing, and the distance between Freud, Jung, modern research and myth tells you more than any single verdict could.
Freud
Freud's account was built on individual life and does not extend well to this. Saying so is more honest than stretching it, and the stretch has been tried often enough to know how it reads.
After Freud, The Interpretation of Dreams (Brill trans., 1913), public domain.Jung
A Jungian reading would treat collective violence as collective material rather than personal, which is one of the places where the framework has something to say, and would be careful not to make it the dreamer's fault.
Our summary of a Jungian reading, in our own words, not Jung's. See Jung, ed., Man and His Symbols (1964).Modern
For people with direct experience, replaying and near-replaying dreams are documented and tend to change as waking distress changes, and treatment for that exists and works. For everyone else this is media residue, and it is common. If these dreams are frequent or you are not sleeping, that belongs with a doctor rather than with a dictionary.
Our summary of trauma-dream research. See Barrett, ed., Trauma and Dreams (1996). Dream content is not treated in that literature as evidence of past events.Mythological
Traditions record massacres constantly, usually from the side that survived, and the reader of any such account is being told what somebody wanted remembered.
Rosmerta Publishing editorial synthesis (after Frazer; Bulfinch).How can writers use this symbol?
The same symbol, read as craft material rather than as a dream. What it does on the page, how genres use it differently, and what happens when you turn it inside out. Written for novelists, screenwriters and poets who need the symbol to actually work, and it ends with something to try.
In literature
Fiction about atrocity has a well known problem of scale: one death can be written and a thousand cannot, so nearly every serious treatment narrows to one and hopes the reader does the arithmetic.
Rosmerta Publishing editorial synthesis. Our own words; no quoted text.What it does in a story
It removes the individual antagonist, which leaves a story with responsibility and nobody to put it on.
Genre conventions
Historical fiction reconstructs. Testimony refuses to, and the refusal is a position rather than a failure of craft.
How to subvert it
Write the week afterwards in a place two valleys away, where the news has arrived and nothing else has.
Try this
Write four hundred words of a list being checked against a list.
Only the first of these names a source. What a symbol does in a story, how genres treat it, how to invert it and what to try are our editorial judgement as writers and editors, not findings from a body of research. They are offered as craft opinion and should be argued with.