Mariani and Rhoads will each pick a numbered ball out of a basket to settle the race on Friday. Lowest number wins.
Lancaster County election officials tell WGAL-TV such a scenario is unusual.
Mariani says she's surprised there isn't a runoff instead. Rhoads says the idea of casting lots seems odd to him, but he isn't sure how else to pick a winner.
Both candidates say the race wouldn't have come down to chance if they had campaigned just a little harder.