The literary devise known as denouement is used by Jackson to reaffirm her original purpose for writing the story. Denouement is recognized as the climax, turning point, or crisis of the story. This is the part of the story which reveals its innermost complexities. Tessie Hutchinson holds the paper with the black dot on it. She has won "the lottery", however what is going to happen to her is only part of the unraveling of the story. The full intent of the story only reveals itself when little Davey Hutchinson, the son of Tessie, is handed stones by another to participate in the killing of his own mother. Davey is too young to comprend what he is witnessing, and by the actions of another in assisting him to "murder" his own mother only contributes to the perpetuation of this ritual. Davey complies without question or reservation because he is young as does what he is told. This reflects Jackson's commentary on the dangers complaisancy can have on a society. If as a society we accept everything we are told without question, on some level we cease to exist as a "civilization".
Another very prominent literary device, which I find more prevalent than irony, is symbolism. There are symbols everywhere in this story. I could not possibly name all of them, but a few are the black box, the black dot on the piece of paper Tessie draws, the three-legged stool that the box is placed on, the lottery itself, and the names of Mrs. Delacroix (which literally means "of the cross" in French), Mr. Summers, and Mr. Graves, along with Old Man Warner. I won't reveal what they each represent because I do not have enough space here LOL, but look at the section in this eNotes group on "Style."
The most prevalent literary device is irony at the end of the tale. Throughout the story, the lottery taking place seems to be a sort of annual game in which there is a winner. Tension mounts when Tessie doesn't want to draw from the box, and the reader begins to wonder what the problem is. Ironically, the "winner" of the lottery is stoned to death in some sort of sacrficial ritual. It is significant that the story takes place in the beginning of summer. In ancient civilizations, ritual sacrifices took place at this time and the blood of the victim was poured onto the ground as an offering. This was done to insure a good harvest. The people of the town may be participating in a similar type of ritual given the fact that the box is old and beat up, yet they still use it. The lottery is so ingrained in their culture that they cannot let go of it.