His experiences as an advance scout in the Battle of the Bulge, and in particular his witnessing of the bombing of Dresden, Germany whilst a prisoner of war, would inform much of his work. This event would also form the core of his most famous work, Slaughterhouse-Five, the book which would make him a millionaire. This acerbic 200-page book is what most people mean when they describe a work as "Vonnegutian" in scope.
These structural experiments were continued in Breakfast of Champions (1973), which included the many rough illustrations, lengthy non-sequiturs and an appearance by the author himself as a Deus ex Machina. Many hostile reviewers found the book formless, but it became one of his best sellers, and was later filmed.
Although many of his later novels involved science fiction themes, they were widely read and reviewed outside the field, not least due to their antiauthoritarianism, which matched the prevailing mood of the United States in the 1960s. For example, his seminal short story Harrison Bergeron graphically demonstrates how even the noble sentiment of egalitarianism, when combined with too much authority, becomes horrific repression. A case could be made for Vonnegut's form of political satire through extrapolation and exaggeration requiring a science fiction theme, simply as a milieu for proposing alternative systems, while remaining essentially political satire nonetheless. In this sense Vonnegut's work is no more or less science fiction than is Swift's Gulliver's Travels.
In much of his work Vonnegut's own voice is apparent, often filtered through the character of science fiction author Kilgore Trout (based on real-life sci-fi writer Theodore Sturgeon), characterized by wild leaps of imagination and a deep cynicism tempered by humanism. In 1974Venus on the Half-shell, a book by Philip José Farmer; aping the style of Vonnegut and attributed to Kilgore Trout, was published. This action caused a falling out of the two friends and considerable confusion amongst readers.
"There is no reason why good cannot triumph as often as evil. The triumph of anything is a matter of organisation. If there are such things as angels, hope that they are organised along the lines of the Mafia."
(From Mother Night)
"Drawn crudely in the dust of three window-panes were a swastika, a hammer and sickle, and the Stars and Stripes. I had drawn the three symbols weeks before, at the conclusion of an argument about patriotism with Kraft. I had given a hearty cheer for each symbol, demonstrating to Kraft the meaning of patriotism to, respectively, a Nazi, a Communist, and an American. 'Hooray, hooray, hooray,' I'd said."