"In a more rational society, an ability to write would be of great help to [Carrie]. But here, the only people who could read her writing would be those who might punish her for being able to write" (105) (Situational Irony)
It is ironic that in a world of slavery and prejudice, literacy–typically a tool for self-advancement–merits punishment when in the hands of blacks. This is no surprise: literacy is a form of power, and the social structure is designed to keep power in the hands of whites.
"I had almost come to welcome the hard work. It kept me from thinking. White people thought I was industrious. Most blacks thought I was either stupid or too intent on pleasing the whites" (162) (Situational Irony)
It is ironic that Dana eventually comes to (almost) enjoy the grueling work of slavery, which is forced labor. This demonstrates just how much one's environment can distort one's perception: with everything else that happens on a slave plantation, the hard work suddenly doesn't seem that bed.
America's Bicentennial (Situational Irony)
It is ironic that Butler sets her book in 1976 at the bicentennial; Americans celebrated how far the country had come, but when one takes a keen look at race relations, it is a sobering reality that things have not come that far at all.
Dana's Familial Relations (Dramatic Irony)
The novel is filled with the general irony that derives from Dana being related to Rufus and Alice and them not exactly knowing that. It is also ironic that Dana has to save her oppressor's life.