In this excerpt from Shirley Jackson's "The Lottery" the repeated references to stones are best described as an example of metaphor
What is lottery? A lottery is a type of gaming in which numbers are drawn at random in hopes of winning a prize. Some governments forbid lotteries, while others support them to the point that they hold a federal or state lottery. Government regulation of lotteries to some extent is quite prevalent. The most typical rule is that sales to minors are prohibited and that lottery ticket sellers need a licence. Although lotteries were popular in the US and a few other nations throughout the 19th century, by the start of the 20th century, the majority of gambling activities, including lotteries and sweepstakes, were prohibited in the US, much of Europe, as well as many other nations. This held true until a long time after World War II.