The reason "The Lottery" has lasted so many years and is often anthologized and placed in lists of "greatest American short stories," and the like, is that it is a beautifully organized work with each page building suspense and just enough foreshadowing for the reader to understand that something bad is going to spoil this pristine scene Shirley Jackson has created.
A short story doesn't just happen. An author spends countless time choosing each and every word, organizing each plot point, describing each character and then deciding that something just doesn't fit and begins revising again. I have to imagine that happened to an extreme extent with Jackson's "The Lottery."
When discussing author's craft, one of the most ignored items in a story or a novel is the title. Jackson titled this story "The Lottery" because of all of its positive connotations, including the idea of being lucky to win. While the reader doesn't know Jackson is using this title ironically, Jackson plays on the idea that this event is a lucky one.
So, Jackson sets the readers up with the idea that something good is going to happen with the lottery and continues building up the readers' expectations by beginning the story with a serene setting as the day was "clear and sunny, with the fresh warmth of a full-summer day."
However, in the opening two paragraphs, Jackson includes the lightest foreshadowing of danger as "Bobby Martin had already stuffed his pockets full of stones, and the other boys soon followed his example, selecting the smoothest and roundest stones." But Jackson tempers this feeling of anticipation as she includes a sentence about typical young romance as "The girls stood aside, talking among themselves, looking over their shoulders at the boys..."
Jackson also includes characters in her story that add to the foreshadowing of the events to come. Old Man Warner warns about how dangerous it is that other towns are getting rid of their lotteries. While not stated, it's implied because the lotteries were being eliminated because they were doing something that might not be looked upon kindly in the modern world.
Jackson's characters in "The Lottery" are also relatable to the readers. Besides Old Man Warner, each character seems like he or she would fit in in modern society. This creates empathy among readers and increases the terror and shock when "a stone hit [Tessie Hutchinson] on the side of the head" and she kept repeating, "It isn't fair, it isn't right."
Without crafting this story exactly, "The Lottery" would be incapable of providing the shock needed and the shock for which Jackson clearly aimed. Jackson's masterful use of narrative technique and characterization created a story that caused maximum effect.