At the annual dinner of Kollel Toras Rashbi there was a limited raffle for a plane ticket to Israel. “Only 100 raffle tickets will be sold,” the sign read. “$25 and you might be at Rabi Shimon bar Yochai’s kever in Meron next year!”

Toward the end of the meal, Mr. Simon, the director of the Kollel, announced: “And now, the Meron raffle!” He put the raffle tickets into a box, mixed them around and pulled out a name. “Mr. Strauss!” he declared. “Enjoy next year in Meron!”

While Mr. Strauss was being congratulated, Yankel noticed a raffle ticket lying on the floor. “Hold it!” Yankel said to Mr. Simon. “There’s a raffle ticket belonging to Hillel that was not in the box.”

Mr. Simon examined the raffle ticket. “You’re right,” he said to Yankel. “Hillel’s ticket was left out inadvertently.”

Mr. Simon asked Hillel to come over. “We’ll refund your money,” Mr. Simon said to him.

“I want a fair chance at the plane ticket,” objected Hillel. “If the raffle was erroneous, you’ll have to redo it!”

Meanwhile, Mr. Strauss overheard the discussion. “I’m willing to share the prize with you,” he offered Hillel. “I’ll give you $100; it’s much better for you than the 1-percent chance of winning if we redo the raffle.”

Hillel thought for a minute. “OK, deal” he said. “Leave it as is,” he said to Mr. Simon.

Yankel complained, though. “The lottery was not done properly,” he said. “It’s got to be redone.”

“What’s wrong?” Mr. Strauss said to him. “Hillel doesn’t mind. You didn’t lose out. If anything, your chances were higher because Hillel was left out!”

“Nonetheless,” said Yankel, “the lottery was erroneous and needs to be redone!”

“Rabbi Dayan is sitting here with us,” Mr. Simon said. “Let’s ask him!”

“Hillel’s ticket was omitted from the raffle,” Mr. Simon said to Rabbi Dayan. “The winner is willing to settle with him, but another participant wants to invalidate the lottery entirely. Must it be redone?”

“If the lottery was done improperly, it is null and void,” replied Rabbi Dayan. “Any participant can insist that it be redone.”

“What is the source for this?” asked Mr. Strauss.

“The Gemara (B.B. 106b) teaches that if two brothers divided their inheritance through a lottery, and a third, unknown brother arrived later, the lottery is null and void and must be redone,” answered Rabbi Dayan. “The Shulchan Aruch rules, based on Tosafos, that this is true even in the following case: There were three fields and two brothers initially took one field and half of the third, and the heretofore unknown brother received the third field through a second lottery. The two brothers can insist on redoing the lottery also on the remaining two fields, even though the third brother has no claim on those fields” (C.M. 175:3).

“How does that apply here?” asked Mr. Simon.

“The Chavos Yair (#61) applies this to our case, where a name is omitted from the raffle,” explained Rabbi Dayan. “Any participant can invalidate the lottery, even though he suffers no direct loss to warrant that the lottery be redone on account of the mistake. The same is true if someone’s name is entered twice, whether that person won or not” (see Pischei Teshuvah, C.M. 175:1; Pischei Choshen, Kinyanim 21[32].)

“What is the logic?” asked Mr. Simon.

“The Chavas Yair explains that a lottery is dependent on the good fortune that Hashem grants,” replied Rabbi Dayan. “It says in Mishlei (16:33), ‘[When] the lot is cast … its entire judgment has been decided by Hashem.’ Thus, when the lottery is not just, it cannot be expected that Divine assistance was associated with the lottery.”

“What if no one complains?” asked Mr. Simon. “Must the lottery still be redone?”

“Mishneh Halachos (3:193) infers from the Chavas Yair that only if someone demanded redoing the lottery is it necessary,” answered Rabbi Dayan. “However, if all the participants accepted the results of the lottery, it is not necessary to redo it, despite the error.”