Asyndeton is the omission of conjunctions where grammar would normally supply them. Items are set side by side with nothing between them but commas, and the list arrives all at once rather than one piece at a time.
Where polysyndeton slows a sequence down, asyndeton compresses it. The effect is speed, and often finality — a list that does not pause to connect its parts sounds like a list that did not need to.
Caesar's report of a campaign, in full: “Veni, vidi, vici.” I came, I saw, I conquered. No conjunction anywhere, and the omission is the message — three stages of a war delivered as though they followed each other without effort or interval.
Asyndeton and tricolon frequently coincide, as they do in Caesar's line. The three-part shape and the missing conjunctions are separate devices doing complementary work.
Asyndeton's compression carries an implicit claim: that the relationship between the items is obvious enough to go unstated. Conjunctions do semantic work — and adds, but contrasts, so concludes — and removing them removes the writer's obligation to say which relationship holds.
That is the device's rhetorical advantage and its hazard. “Taxes rose, investment fell, unemployment climbed” invites a causal reading without ever asserting one, which means it also cannot be challenged as a causal claim. The sequence does the arguing while the grammar stays innocent.
Read carefully, an asyndetic list is a place to slow down and ask what the missing conjunction would have been, and whether the writer could have defended it. Often the answer is and, and nothing is hidden. Sometimes the answer is therefore, and a great deal is.
