NCAA hockey follows a rulebook that closely resembles the NHL, but with several key differences. An outline of the most significant differences is included below.
NCAA Rulebook  (.pdf)
Overtimes and tie games. Overtimes are five minutes, sudden death, played five-on-five (unless penalties carry over from regulation or are called during overtime). Teams switch ends for overtime (guarding the same net as they did in the second period).
College games can end in ties, although conferences may elect to use alternate formats (three-on-three, shootouts) to award points in league standings after the initial five-minute OT. Those that have elected to do so use the following formats after the initial five-minute OT:
Big Ten: A three-person shootout follows the initial overtime; if still tied a sudden-death shootout follows
NCHC: Five-minute 3-on-3 overtime; if still tied move to a sudden-death shootout (not best of three; can end as quickly as one shooter per team)
WCHA: Five-minute 3-on-3 overtime; if still tied move to a sudden-death shootout (not best of three; can end as quickly as one shooter per team)
Atlantic Hockey, ECAC Hockey and Hockey East games that are tied at the end of the first five minutes of overtime end in ties.
Non-conference overtime formats, beyond the first five minutes, are agreed upon by the head coaches prior to the game. There is no "dry scrape" before overtime in the college game.
Goal scored during delayed penalty. If a team scores a goal during a delayed penalty call, that call is still enforced and the penalty served. The ensuing faceoff takes place at center ice.
Contact to the head. Any time a player makes direct contact with the head or neck of an opponent it is a major penalty and game misconduct at a minimum. The responsibility lies with the player making the hit to avoid contact with the head and neck area of an opposing player. A player delivering a check to an unsuspecting and vulnerable player puts themselves in jeopardy of being penalized under this rule.
When the initial force of the contact is a shoulder to the body of the opponent and then slides up to the head or neck area, this is not classified as contact to the head. This type of action may still be penalized, at the referee’s discretion, as another penalty (e.g., charging, roughing, elbowing, etc.).
No trapezoid. There are no restrictions on where a goaltender can handle the puck behind his goal line.
Puck shot directly out of play in defensive zone. There is no automatic penalty for clearing the puck over the glass in the defensive zone, although a delay of game penalty can be called at the discretion of the officials if the action was deemed to be intentional.
Hand passes in the defensive zone. Hand passes are not allowed in the defensive zone in NCAA play, with those situations whistled down as they would be elsewhere on the ice. When the infraction takes place in the defensive zone the offending team will not be able to change players prior to the ensuing faceoff.
Pucks directed/deflected off of the skate. In the summer of 2012 the NCAA rules committee adopted an approach very similar to the NHL when it comes to pucks entering the net off an offensive player’s skate. Goals are allowed unless the referee determines that the puck was intentionally kicked.
Fighting. Fighting is penalized with a five-minute major and a game disqualification, meaning that the offending player is out of that game and the next game.
Face shield. All players are required to wear an approved face mask or shield.
Contact After the Whistle. The NCAA committee has emphasized strict enforcement on altercations after the whistle. Additionally, when altercations occur, players must respect and follow the direction of game officials. Players must not resist an official or persist in continuing an altercation after the player has been ordered to stop. Rule 6-1-l calls for a misconduct, game misconduct or disqualification at the referee’s discretion in this area.
Faceoffs. In faceoffs in an offensive zone, the defending team will put their stick down first for the faceoff. In all neutral-zone faceoffs, the visiting team puts their stick down first.
Video replay. During the season, at a conference’s discretion, video replay may be used by the on-ice officials using a monitor at the scorers’ table. All goals are reviewed initially by a replay official. Should a situation occur that the replay official believes requires a review (or if the on-ice referee decides to review a play), the replay official will offer information and assist in the review. The on-ice referees will review the play at the scorer’s bench and make the decision.
In the NCAA Tournament and in conference tournaments or regular-season games with suitable facilities, a video replay official will be assigned to a booth in the arena, much like in the NHL.
Video replay may be used, if available, to determine if a play that led to a goal was offsides or if the attacking team had too many men on the ice. During the regular season, prior to the final two minutes of regulation and overtime, these reviews require a coach's challenge.
During postseason competition, officials may use video replay during a game to review penalties that would result in the removal of a player to ensure proper enforcement.
Goaltenders. Teams may dress up to three goaltenders in a game.