Many events in the book are repeatedly described from differing points of view, so the reader learns more about each event from each iteration, with the new information often completing a joke, the setup of which was told several chapters previously. The narrative's events are out of sequence, but events are referred to as if the reader is already familiar with them so that the reader must ultimately piece together a timeline of events. Specific words, phrases, and questions are also repeated frequently, generally to comic effect.
Much of Heller's prose in Catch-22 is circular and repetitive, exemplifying in its form the structure of a Catch-22. Circular reasoning is widely used by some characters to justify their actions and opinions. Heller revels in paradox, for example: "The Texan turned out to be good-natured, generous and likable. In three days no one could stand him", and "The case against Clevinger was open and shut. The only thing missing was something to charge him with." This atmosphere of apparently logical irrationality pervades the book.
While a few characters are most prominent, notably Yossarian and the Chaplain, the majority of named characters are described in detail with fleshed out or multidimensional personas to the extent that there are few if any "minor characters."
Although its non-chronological structure may at first seem random, Catch 22 is highly structured. It is founded on a structure of free association, ideas run into one another through seemingly random connections. For example, Chapter 1 entitled "The Texan" ends with "everybody but the CID man, who had caught a cold from the fighter captain and come down with pneumonia." Chapter 2, entitled "Clevinger", begins with "In a way, the CID man was pretty lucky because outside the hospital the war was still going on." The CID man connects the two chapters like a free association bridge and eventually Chapter 2 flows from the CID man to Clevinger through more free association links.
Yossarian comes to fear his commanding officers more than he fears the Germans attempting to shoot him down and he feels that "they" are "out to get him." Chief among the reasons Yossarian fears his commanders more than the enemy is that as he flies more missions, Colonel Cathcart increases the number of required combat missions before a soldier may return home; he reaches the magic number only to have it retroactively raised. He comes to despair of ever getting home and is greatly relieved when he is sent to the hospital for a condition that is almost jaundice. In Yossarian's words:
- The enemy is anybody who's going to get you killed, no matter which side he's on, and that includes Colonel Cathcart. And don't you forget that, because the longer you remember it, the longer you might live.
While the military's enemies are Germans, none appear in the story as an enemy combatant. This ironic situation is epitomized in the single appearance of German personnel in the novel, who act as pilots employed by the squadron's Mess Officer, Milo Minderbinder, to bomb the American encampment on Pianosa. This predicament indicates a tension between traditional motives for violence and the modern economic machine, which seems to generate violence simply as another means to profit, quite independent of geographical or ideological constraints. Heller emphasizes the danger of profit seeking by portraying Milo without "evil intent." Milo's actions are portrayed as the result of greed, not malice.