In any sport, there's a "code" among players that simply cannot be broken.
If a hitter gets plunked in a baseball game, odds are that his pitcher will bring the same noise back.
When a superstar takes a hard foul, your team's best player will probably get hit on their next trip to the hoop.
If you take a shot at the quarterback, you're putting your quarterback at risk for the rest of the game.
And in hockey, if you break one of these 13 rules, there might be hell to pay.