The surprise in Shirley Jackson's short story, "The Lottery," is that unlike lotteries today that give away large sums of money to the winners, in this story, the person whose name is chosen is not a "winner," but definitely a loser.
The person who gets the paper marked with the black spot is the one whose life is sacrificed as everyone picks up stones and hurls them at that person until he or she is dead. Even the children are encouraged to participate in the stone throwing. Strangely, the event first seems like a gathering of townsfolk for a picnic or festival. People chat and act as if it is any other day. It is not until late in the story that the reader starts to get an idea that this is anything but a normal day.
The story is not clear as to why they carry out this tradition. It has been going on for a very long time—since the village was first settled. People in town accept it; for example, when Tess, who is chosen, starts to complain (in an understandable panic), her husband tells her to "shut up." Some people discuss that nearby towns have been talking about doing away with the lottery, but this town does not show these signs. When the Adamses convey this information to Old Man Warner, he replies:
Next thing you know, they'll be wanting to go back to living in caves. There's always been a lottery.
Old Man Warner does say "Lottery in June, corn be heavy soon." The inference we can make there is that this about sacrifice for a good harvest so that the town is able to survive the winter.