While watching the men’s hockey tournament, there are a few differences that will appear compared to your normal NHL game. You may have heard that fighting is banned in international hockey – a scrap will result in automatic ejection – but there are other differences in the International Ice Hockey Federation (IIHF) rulebook that arguably have a bigger impact when the puck is in play.

We saw one play of those out in the very first game of the tournament, when Finnish defenseman Olli Maatta immediately sprinted to the bench after his helmet fell off. In the NHL, players are allowed to finish their play for a few seconds before heading off. In international play, they must leave the ice right away.

If a game goes beyond regulation in the round-robin, you’ll recognize the five-minute, 3-on-3 overtime and (if necessary) shootout structure. However, it’s worth noting teams don’t switch ends of the ice at the end of regulation like they do in the NHL, making it much easier for players to change with their benches still near the defensive zone, and therefore harder to wear out the opposition and create scoring chances.

The round-robin standings will be set using the following formula – three points for a regulation win, two for an overtime or shootout win, one for losing in OT or a shootout, and none for a regulation defeat. In the NHL, a win is worth two points regardless of how look it takes, although the 4 Nations Face-Off used this same methodology.

Additionally, shootouts consist of five rounds instead of three. If the teams are still tied at five rounds, players who previously shot can go again. In the NHL, every player must go once before a player repeats, something that’s only happened once. That’s how T.J. Oshie was able to take six attempts – and score four times – against Russia in 2014 (although back then, a standard shootout was only three rounds instead of five).

In the elimination round, overtime will stretch to 10 minutes before a shootout starts. However, the gold medal game will feature unlimited 20-minute overtime periods if the game is tied after 60 minutes. In both instances, though, OT will still be 3-on-3. That's a stark difference from the Stanley Cup Playoffs, where all overtimes are 20-minute periods played at 5-on-5.

One more thing to consider: while video replay does exist, all reviews will come from a team challenge, increasing the importance of video coaches. Teams can challenge go or no goal calls for factors such as offsides or goaltender interference, as well as overturning a delay of game penalty for shooting the puck over the glass from the defensive zone without a deflection.

Teams have unlimited challenges, but there’s a penalty for getting one wrong – a two-minute minor for the first unsuccessful challenge and a four-minute double minor for all subsequent upheld calls.

In general, games are officiated a bit tighter at the international level. Reckless hits and play around the crease are two areas where referees may blow the whistles in situations where they may not in the NHL. Some of the officials do come from the NHL, but not all of them. So, there will be some adjusting on their end as well as the tournament kicks into high gear.