The irony of von Rauffenstein's affection for Captain de Boëldieu
Captain von Rauffenstein (a member of the German army) and Captain de Boëldieu (a member of the French army) are fighting each other in World War I. They should be avowed enemies; however, von Rauffenstein has great affection for Captain de Boëldieu (who he also treated extremely well), which is deeply unexpected.
The irony of von Rauffenstein's lunch invite
Most captors would not invite their prisoners to a wonderful lunch with delicious food. However, von Rauffenstein unexpectedly invites the two captured French soldiers to lunch.
The irony of von Rauffenstein shooting de Boëldieu
When von Rauffenstein shoots de Boëldieu, he aims for his legs. Ultimately, though, he ends up shooting him in the stomach—something unexpected because no friend would shoot another friend anywhere.
The irony of Lieutenant Maréchal's sacrifice
Despite falling in love with Elsa and promising to start a life with her, Lieutenant Maréchal decides to head to Switzerland with Lt. Rosenthal, a man who he barely knows. Normally, a man who had found the woman of his dreams would not leave her to be with a man who he barely knows to help him escape.
The irony of wealth
Ironically, it is the characters in the film who do not come from money that end up the happiest. They are much happier, in fact than the characters that do not come from wealth. This is unexpected: the film's wealthy characters often make it seem like they are better and happier because they are wealthy.
