ST. LOUIS -- Monday's Winter Classic between the Chicago Blackhawks and St. Louis Blues started on time, but the potential for inclement weather led the NHL to set up contingency plans.

The forecast had called for rain and thunderstorms during the day at Busch Stadium.

The game will be deemed official once two periods have been played, awarding the win to the team that is leading when the game is called. If the game is tied and has to be stopped after two periods, each team will get a point, and the teams will hold a shootout. If the conditions do not permit a shootout at Busch Stadium, the teams will hold it before their scheduled game at the United Center on Feb. 26.

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If the game is started and must be stopped before two periods have concluded, the game will be postponed and played in its entirety Tuesday at Busch Stadium. If the weather doesn't cooperate then, the teams will meet at Scottrade Center at a date to be determined.

Normally, the game is played on New Year's Day, and if that had been the case this year, the weather would have been perfect for an outdoor game. Instead, the NHL celebrated its 100th anniversary with the Centennial Classic between the Detroit Red Wings and Toronto Maple Leafs on Sunday at BMO Field in Toronto. That game was delayed a half-hour because of sun glare on the ice.

The Winter Classic has never been postponed to the following day, but that had been an option. The NHL made the call Monday morning to go ahead as planned.

Players understand the challenges of playing outside and were prepared for a delay.

"You prepare like you would a normal game," Blackhawks captain Jonathan Toews said Sunday. "You don't really know how it can turn out, but at the end of the day, it's the same for both teams, and it comes down to who's handling the conditions the best. We played in a game at Soldier Field a couple of years ago, and it was snowing like crazy, and it was tough to even see the puck at times. It was slowing down on you, and it slowed the pace of the game down a little bit. If you don't make excuses and you just go play through it and know that it's a challenge both teams have to deal with, maybe you can take advantage of the rough conditions in some ways."

Players, including the alumni, have been impressed with the ice surface in St. Louis, and there haven't been any issues, but a significant amount of rain could change that.

"It's not an ordinary situation being outside your building, but obviously, we have to adjust to weather," Blackhawks goalie Corey Crawford said.