Papa John's Super Bowl Coin Toss 2013 is a rare opportunity to get free pizza from the popular pizzeria.

For at least the second year in a row, Papa John's has set up a contest in which the pizza company will award a free pizza to American voters who guess the Super Bowl XLVII coin toss correctly online after simply signing up to be Papa John's Rewards members.

But you've got to be in it to win it, so be sure to log on to the official Papa John's Super Bowl Coin Toss website and cast your vote for "heads" or "tails" by 11:59 p.m. PST Saturday, the day before the big game between the San Francisco 49ers and the Baltimore Ravens.

The official coin toss will take place shortly before the game kicks off at the Mercedes-Benz Superdome in New Orleans, La., at 6:30 EST on Sunday, and at that moment entrants will know whether or not they are winners of the coin toss prize, namely one large one-topping pizza.

It's actually a fairly simple process. Start out by simply visiting the official Papa John's Super Bowl Coin Toss website by clicking this link.

Next pick "heads" or "tails" and fill in the required information in order to sign up with Papa John's Rewards and inform them of what email address you would like for the chain to send the promotion code for a free pizza.

Then simply click "Vote Now," and you're all set!

The website provides the following explanation of some of the rules of the game:

"Winners will receive a promotion code good for a FREE LARGE 1-TOPPING PIZZA, which can only be redeemed at papajohns.com. The promotion code will be emailed to winners on Monday, Feb. 4, by 11:59 p.m. PST. One Vote Per Person."

Last year, the coin landed on "heads," which meant the many thousands of customers who entered the contest were treated to the free meal.

"America, you called it right!" the coin toss contest website read after the toss last year.

If you are lucky enough to guess the right side of the coin this year, you may be reading a similar congratulatory message come Super Bowl Sunday and eating a free pizza shortly after that.