NHL preview: New rules for the 2015-16 season

Fans will notice two significant changes this season: a 3-on-3 overtime intended to decrease the number of shootouts and a coach's challenge. Here are the details:

• The 4-on-4 is being replaced with a sudden-death 3-on-3 overtime for an additional point in the standings. If nobody scores, there will be a shootout. In the preseason, 3-on-3 led to several odd-man rushes and teams trading entertaining scoring chances. The Wild played four, winning three (Zach Parise, Matt Dumba and Erik Haula scored the goals) and playing to a scoreless tie in one. Joked Wild goalie Niklas Backstrom, "Fans love it, I don't know if the coaches love it, players probably love it and goalies hate it."

• Teams switch sides at the end of the third period, meaning there's a long line change like the second period.

• At no time can a team have fewer than three skaters. If a minor penalty is assessed, teams play 4-on-3. If a second minor penalty is assessed, teams play 5-on-3.

There are three scenarios in which a coach can request a challenge:

1. Offside play leading to a goal: Goals will be reviewed for a potential offside infraction if, 1) the puck does not come out of the attacking zone again; 2) all members of the attacking team do not clear the attacking zone between the time of the offside play and the time the goal is scored. If a goal is reversed, the clock, including penalty time, will be reset to the time an offside should have been called.

2. A goal where the defending team asserts the goal should have been disallowed due to "interference on the goalkeeper," as described in the NHL rule book.

• A team may request a challenge only if they have their timeout available (likely will cause coaches to think twice about burning their timeout on icings) and it must be initiated prior to the resumption of play.

• If the challenge does not result in the original call being overturned, the team exercising the challenge will forfeit its timeout.

• If the challenge results in the call being overturned, the team will retain its timeout.

• In the final minute of the third period and any point in overtime, NHL Hockey Operations will initiate the review of any scenario that would be subject to a coach's challenge.