With the AFC Championship tied at 31 after four quarters, it'll take overtime to decide whether the New England Patriots or Kansas City Chiefs represent their conference in Super Bowl LIII. This after the Rams and Saints took the NFC Championship into overtime.

So here's a quick refresher on the rules for overtime in the NFL playoffs:

Unlike in the regular season, playoff OTs feature 15-minute periods until a winner is declared. Each team still receives at least one possession unless the first team with the ball scores a touchdown or records a safety.

You can follow along with the end of Patriots-Chiefs in our live blog of the game.