The supreme irony in "An Occurrence at Owl Creek Bridge" is that Peyton Farquar is hanged from a bridge he didn't succeed in destroying. He was approached one day on his plantation and told by a man—who later turned out to be a Union Army scout—how easy it would be to burn down the bridge. And so Farquar did what he thought was his duty, or at least tried to. However, far from dealing a mighty blow to the Union forces as he'd hoped, Farquar's actually signing his own death warrant by carrying out such a hare-brained scheme.

In "Chickamauga" it's ironic indeed that the little boy should be scared of a harmless rabbit, but not the raggle-taggle band of bloodied soldiers returning from battle. The boy has no conception of the harsh realities of war; if he thinks about it at all, it's only as one gigantic adventure. He's so far removed from what's really happening at the front that he thinks the wounded soldiers' blood is just paint, like the kind that clowns wear.

Irony is an important literary element in both of Ambrose Bierce's stories. In fact, it is pretty central to most of his writing. In "Occurrence," the irony is two-fold. One aspect is that Peyton thinks that destroying the bridge will help the situation, when ultimately, that is where he meets his death. In addition, it is ironic that just as the noose tightens around his neck, he thinks he escapes, when in reality, he dies.

In "Chickamauga," the irony is that while the young boy plays soldier, there are grown soldiers in real life all around him. Bierce makes a statement that war adversely affects everyone and when we show children how to wield swords and fight, they will one day take part in real wars and die. In both stories, Bierce effectively uses irony to convey a sense of the tragedy and consequences of war.