New York City is using ranked choice voting in its Democratic mayoral primary election. Here's how it works: Rather than pick just one candidate, voters get to rank several in order of preference.

The winner of the Democratic primary will face Adams, Republican candidate Curtis Sliwa, and independent candidate Jim Walden come November, but is likely to become the next leader of the city, which has selected a Democrat in the past three mayoral elections. Polls are open in the city until 9 p.m.

Andrew Cuomo and Zohran Mamdani are the leading candidates in the Democratic primary, but don't expect to know the winner Tuesday night.